How to Charge Batteries in Parallel With Different Capacity

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  • Опубликовано: 16 ноя 2024

Комментарии • 215

  • @cleversolarpower
    @cleversolarpower  6 месяцев назад +3

    🎁 Free Diagrams: cleversolarpower.com
    📖 My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified
    💵Use coupon code: clever6 to get 6% discount for Litime batteries: cleversolarpower.com/litime (cheaper than amazon)

  • @bradk8702
    @bradk8702 8 месяцев назад +7

    Thank you so much for the generous candid info that is presented so CLEARLY.
    Received your book from Amazon three days ago 👍

  • @mrhalfstep
    @mrhalfstep 3 месяца назад +4

    I wasn't searching for this topic exactly, but your site was the first hit that I got. You didn't address the issue that I was asking about, but I bet that you are the guy that can answer my question, all the same, and other folks may also have the same question, so if I might....
    I have an assortment of 12.8 volt LFP batteries that are of various ages, but none have seen a lot of use. They also vary in their capacities from 100AH to 300AH. I have them to connect to various inverters as I need them when my power goes out, rather than all connected together to one big grid down backup system. It's just the way it has evolved for me as I started fooling around with LFP batteries. They keep getting cheaper and lighter and smaller and I keep buying them. My issue is that I want to have them stored in a convenient place with some sort of charger that will keep them at a good maintenance charge until I need one of them. I'm old and I just don't trust myself to remember to go around and charge each one if I suspect I'm going to need it during a spat of bad weather, for instance. I want them to always be at the ready when they need to be put into service. They won't have any load on them, they will just be sitting on shelves.
    My vision is a 20 amp charger set to 14 volts or so, connected to 2 solid aluminum bus bars, about 3/8 X1/2 inch in cross section, with a bunch of 12 AWG wires with small alligator clips connected to them so that I can unclip a battery, use it, leaving the other batteries connected, and then return it to be reconnected when I'm finished with it. Maybe even several batteries at one time. I may make it a little more sophisticated than that, but that's the basics. My question is, do I need to be concerned with keeping wire lengths the same and fusing each charging lead, since I'm not going to be actually discharging them while they're in the rack?
    Thanks very much for any help you can offer.

    • @cleversolarpower
      @cleversolarpower  3 месяца назад +3

      Try to have the same wire lengths. You have to fuse every wire.

  • @aaronb483
    @aaronb483 8 месяцев назад +1

    i never considered all those issues. Everything you said made complete since to me.

  • @MirandojrUnciano
    @MirandojrUnciano 8 месяцев назад +4

    Very well explained

  • @philbrooke-little7082
    @philbrooke-little7082 8 месяцев назад +9

    Lithium and lead acid work very well together so long as the lithium has a programable BMS. The advantage of doing this is that it saves the cost of having to get lithium profile chargers and it protects an alternator in the event of a BMS disconnect. It also gives redundancy. I’ve been running hybrid for several years and so have many other boaters.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      What voltage are you setting your charge to?

    • @philbrooke-little7082
      @philbrooke-little7082 8 месяцев назад +14

      @@cleversolarpower I set the BMS to disconnect charge at either 14 or 14.2v the chargers are set at standard lead acid so 14.4 and a float of 13.5 which suits both lead and lithium. Setting the BMS lower than the chargers ensures that you never get a ‘low voltage overcharge’ situation from the alternator or from solar controllers absorbing before going into float. The 14 / 14.2v is chosen as it allows the battery to enter the upper ‘knee’ portion of the charge curve and perform balancing if needed. I use 14v when solar is the main charge source and sometimes 14.2 if using the alternator as the current on mine can be fairly high (0.25+C) as that allows the battery to get a bit more full than it would at 14v. 14v works well with solar as, at the often lower charge rates, it gets the battery to around 99%+ full. My system is data logged at one minute intervals and I have used the data gathered to come up with those settings.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +10

      Thanks for your extensive answer. I might do a video about this when i run some tests.

    • @samv5475
      @samv5475 4 месяца назад

      @@philbrooke-little7082 do you have a video, or a diagram of your setup? Do you have one DMS for all the batteries, or more than one (ie one bms for the lithium, and one for the lead acid)? Your disconnect charge of 14 or 14.2 V is for both types of batteries?

    • @philbrooke-little7082
      @philbrooke-little7082 3 месяца назад

      @@samv5475 only the lithium has and needs a BMS. the lead acid is always connected and is there for when the bms disconnects on full charge, cell over or under volts, battery undervolts and any temperature based disconnect. It act as a redundant system and also to protect devices such as the alternator and boat loads should the bms disconnect.

  • @DiHandley
    @DiHandley 8 месяцев назад

    What an excellent and very helpful channel. I have just installed 3 x 120a 12 volt batteries in parallel connected via two very thick solid copper busbars for a total of 360 amps. I took the negative off the first battery and the positive off the last and then ran them up to separate busbars for distribution to - 240vac/12dc charger, dc to dc converter and a 3000 watt inverter. I hope I did the right thing. I have now subbed to your fantastic channel. Thank you.

  • @NaturalBodyIntelligence
    @NaturalBodyIntelligence 10 дней назад

    With your example showing red to battery 2 and black to battery 4 in a 5 battery system, is this also where I wire the solar charge controller? I think it's both as I'd want the current also flowing in evenly.

  • @donm1547
    @donm1547 8 месяцев назад

    Thank you for the PDF download, I just want to say that your disclaimer with conductor sizing based on the 90°C column really should be based on the 75°C column because most devices that will be terminated to that cabling will not be rated with a 90° C termination. Therefore the possibility of excessive heat being transferred through the terminations to the device could either destroy the equipment or cause a warranty issue.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +1

      I have never heard about lugs having a temperature rating. I researched it, and you are right; they do have a temperature rating. However, I do not think it plays a significant role as long as they are quality lugs and not cheap lugs. A welding wire rated at 105°C should then also be downgraded to a 75°C rating; that doesn't make sense to me. We did not take this into account when working for a major chemical company. I have a video about the quality of lugs coming out soon.

  • @kenkrommenacker8649
    @kenkrommenacker8649 8 месяцев назад +1

    Thank You for all the info, and also just ordered your book.

  • @subbuk6557
    @subbuk6557 2 месяца назад

    Excellent explanation one query please, I have connected 3 batteries in parallel first 200mah second 200 mah and the third 150 mah to an inverter 950VA/12V, what will be charging and consumption sequence, request your feedback thanks

  • @mikemosc3254
    @mikemosc3254 Месяц назад

    i fucking love you man. it's like you're my guardian angel. the minute i need information the correct video pops up from you. you are a lifesaver. a true angel.

  • @808pathfinder
    @808pathfinder 6 месяцев назад +4

    Just watching the video made me hit the like button and you showing all the wirering diagram made me hit the Sub, thanks for sharing

  • @ravicabral2522
    @ravicabral2522 9 дней назад

    Can you clarify something?
    In this video you have a slide with a 150A load that shows rthe 110 Ah battery providing 50A and the dual battery bank providing double.
    But you have a later video where you say that the smaller battery will put out disproportionately MORE charge because of jnternal resistance.
    I am particularly interested in this subject as i have a lead acid configuration where a battery switch has a single 110Ah 12v battery on one side and two identical batteries in parallel on the other.
    General usage seems to result in the single battery deteriorating over time.

  • @tombloemker9434
    @tombloemker9434 3 месяца назад

    Love your explanation! I want to build a dc power box, with solar charging. I want to use various tool batteries of the same voltage but diffrent capacities. Could I connect the charge controler to the bus? I assume the cut off would not hurt the smaller capaticy packs?

  • @jeremygrebe2647
    @jeremygrebe2647 5 месяцев назад

    Hi
    From Colombo, Sri Lanka
    I am using a microtek 2335 hybrid inverter, 2 x 12v 200ah Okaya Opgel and 3 x 375 REC panels.
    I operate with smart metering ie - Day time 5.30 am - 6.30 pm, Peak 6.30 pm -10.30pm, Off peak 10.30pm - 5.30 am.
    I auto switch off the peak time by way of timer and contactor thereby zeroing peak current and charge in off peak, and save during day time via solar.
    Net saving has been almost 65%.
    My house is single phase and I have split wired my house as follows.
    1. All lights, fans, TV, Fridge,audio including plug points in room through inverter /solar hybrid.
    2. Iron, Oven, Microwave, Electric Kettle, Air Fryer,Washing Machine induction all direct to grid.
    Although system works fine if I operate at full capacity during peak I found my battery id's almost fully utilized and insufficient if I have an extended power cut.
    Watching your video I want to increase this same system by 6 batteries of same type. Make 3 sets of 24v x 200ah and connect each set to a 24v/200ah 5 stage intelligent charger ( so total 3 sets of batteries & 3 chargers) I will set a timer/contactor to charge these during off-peak and day time only.
    This will give me 19w reserve and hopefully many years of use.
    I intend connect 1st set to hybrid inverter and balance 3 sets as tag on parallel (with their grid chargers)
    Please advise your thoughts.
    Thanks and Regards
    Jeremy
    PS - Anyway I can discuss with you +94776783218

  • @dazzrhilux
    @dazzrhilux Месяц назад

    Hi 5 battery's in parallel were should or which battery should you ground to chassis and which battery to you load equipment..thank you

    • @cleversolarpower
      @cleversolarpower  Месяц назад

      From the main negative post or negative busbar. I made a video about grounding.

  • @davidhughes2932
    @davidhughes2932 5 месяцев назад +1

    Question: I have 2 100 AH batteries and one 200 AH battery wired in parallel to busbar. Do you recommend a charging equalizer?

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад +1

      No, parallel equalizes itself. The bigger battery will draw twice as much power, but that's ok.

  • @twiddler71
    @twiddler71 8 месяцев назад +2

    Thank you for these great videos and I also have your book which has lots of great info. Is there a good way to test the capacity of AGM batteries? I have a bunch of used AGM batteries I'd like to use, but it's difficult to tell how much capacity each one has. I know some people say you have to run a load all the way down to 10.5v and measure the current draw, but I don't want to harm the battery.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +2

      Thank you for the kind words 🙏. If you have a shunt you can draw it down to 50% SOC and then double the capacity at the end. Then you know how much is left.

    • @twiddler71
      @twiddler71 8 месяцев назад

      I was thinking about that, but then how can I know for sure when the battery is at 50%? AGM batteries will drop voltage under load.
      @solarpower

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +1

      Good question, use a c-rate that is 0.05C for lead acid (20 hours). Then the voltage will not drop that much. Check by disconnecting the load and see if the voltage settles.

    • @twiddler71
      @twiddler71 8 месяцев назад

      @@cleversolarpowerI tried using a DL24 load tester at 10amps load down to 12v, but my readings didn't seem consistent. I recharged all my batteries, then let them sit for 2 days and see which ones remained at the highest voltage. I had 3 out of 8 that were above 13v, so I'm guessing those are my best batteries.

  • @jlacoustic4450
    @jlacoustic4450 5 месяцев назад

    Thx so much for your guidance. Can I connect in parallel a 100ah 24v to my old 20 ah 24v using your wiring advice, positive on my 100ah end and negative on 20ah end?
    Would it cause any problem or harm my 20 ah battery in anyway?

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад +1

      No. 1/6 of the energy or current will come from the 20ah battery. The rest will come from the bigger battery.

    • @jlacoustic4450
      @jlacoustic4450 4 месяца назад

      @@cleversolarpower thanks so much for your reply. This would actually pave way for later expansion.
      I must balance 2 batteries to same voltage before connecting them together, right?

  • @ChrisSgaraglino
    @ChrisSgaraglino 3 месяца назад

    I just watched this video, thank you! I have (4) 100Ah batteries going into my exiting 12v RV with a 1000W inverter. Each battery has a max in/out of 100A. I also have a 150/35 Victron Solar Controller. I’m going to use your Bus Bar recommendation, but I am a little confused on what size fuses I should put on each battery. A little help here would be much appreciated!

    • @cleversolarpower
      @cleversolarpower  3 месяца назад +1

      1000÷12×1,25÷4=26A. Then I would multiply by 1.5 to account for imbalances between the batteries. So that becomes 40A. Fuse with 40A and a wire that can carry at least 40A. Check my wiring calculation video for that.

  • @cndbrn7975
    @cndbrn7975 3 месяца назад

    I have a 72v 40A (max) 500watt (motor) and i'm thinking of using 4 12v 18ah lifepo4 batteries and 2 12v 20ah lead acid batteries.
    The 4 to be wired in series and the 2 acid to power a boost converter, to gain the extra
    24v needed? Using a bus bar to connect the 4 & 2 together before connecting to the boost converter, then to the load.
    Can you give me any insight to this arrangement? ..

  • @neno2363
    @neno2363 8 месяцев назад

    I have four GEL batteries. Two are 100 Ah each, and two are 120 Ah each. The inverter operates at 24V. I have three solar panels, each with 390W and 40V connected in series. The charge controller can operate at 12V, 24V, 36V, and 48V. What is the most optimal way to connect the batteries? Two batteries of 100 Ah in series, two of 120 Ah also in series, and then those two in parallel? Where should I place the fuses and of how many amperes?

  • @douggief1367
    @douggief1367 8 месяцев назад

    Thanks for your great help. I have 3 LifePO4 12v batteries: 1 is 50 Ah, and 2 of them are 75 Ah. I also have a 1500w Pure Sine Wave Inverter. How many of these batteries should I run in parallel? I want to charge 48v EGO batteries as well as other low draw uses like 12v lighting. Many thanks. --Douglas.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      You can run the 3 in parallel. other voltage systems should have different charge controllers and inverters.

    • @douggief1367
      @douggief1367 8 месяцев назад

      @@cleversolarpowerThankyou

  • @majdgreen7983
    @majdgreen7983 8 месяцев назад

    thank you for helpful explanation
    If I have 24v 200A lifepo4 battery used for about 1 year and I wanted to add another battery from same size and voltage and brand name
    could this be done ? what is the precautions ?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      You can add the battery in parallel. Not a problem. The main positive from battery 1 and the main negative from battery 2.

    • @majdgreen7983
      @majdgreen7983 8 месяцев назад

      @cleversolarpower thank you , but I was informed that the inner resistance of LiFePo cells becomes higher by time of using it .. and it is not recommended to connect new batteries with used one. Cuz there will be difference in cells resistance
      What do you think

  • @vitoconginejr3283
    @vitoconginejr3283 17 дней назад

    Can you provide wire sizing? I am preparing (2) 100 Amp Lithium batteries to a busbar to create a parallel 12volt 200 Amp hour system.

    • @cleversolarpower
      @cleversolarpower  17 дней назад

      Check my video on how to size wires. It's in my beginners playlist on my channel.

  • @NOMAD-LEISURE
    @NOMAD-LEISURE 3 месяца назад

    Hi 2x 12v lifepo4 batterys. Both different manufacturer.bith have BMS and Bluetooth ...I want to wire in parallel 200ah + 280ah . Do I need to charge both battery 100% first ,then change my soc app to 480ah or will BMS look after it all as regarding to charging and soc?

  • @CityGirlGoneGreen
    @CityGirlGoneGreen 23 дня назад

    Do you recommend using a bus bar if using only 3 lithium batteries?

    • @cleversolarpower
      @cleversolarpower  20 дней назад

      I recommend using a fuse on every parallel battery. So it's best to use a victron MEGA fuse holder with integrated busbar. You can see it in one of my recent videos. You can also use an MRBF fuse holder on every battery. Then you need fewer cable crimps (but more expensive).

  • @tomp1193
    @tomp1193 5 месяцев назад

    Thanks for the video, i enjoyed it. I have 4 x 240ah 12v Lifepo4 batteries in parallel. Ive come across another 12v 300ah lifepo4 battery(same manufacturer). Would it be safe to add it to my battery bank? Thanks

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад

      Yes, but only in parallel.

    • @tomp1193
      @tomp1193 5 месяцев назад

      Thanks for that. Everything is in parallel.👍

  • @MagsD-o7w
    @MagsD-o7w Месяц назад

    I need a 12v lithium charger with xlr connecter for my wheelchair I have 2x36ah lithium batteries in parallel and at the moment my son is having to lift the seat take the batteries out to charge them separately with crocodile clips we r I'm scotland uk do u have any recommendations plz

  • @GregComin
    @GregComin 6 месяцев назад

    Hey..
    Im making a new solar setup for a caravan n want to be fully off grid n self efficient.
    What would you do for say 3kwh that say could last a couple days?
    What sort of battery capacity would I need and solar n what not??

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад

      Checkout my latest video about designing an off grid solar system.

  • @russell7489
    @russell7489 7 месяцев назад

    VERY clear You are brilliant

  • @victordigitalng
    @victordigitalng 6 месяцев назад

    Thanks for this. I have a technical issue with my setup. I have four 12v 200ah batteries from the same manufacturer. My inverter is a 24v system so I connected two batteries in series to give 24v and parallel with the other two series battery. Now I have the battery bank at 24v 400ah.
    After about 3 hours of use by the inverter, I noticed that the 2 batteries on the negative parallel line will drain to 10v while the 2 on the positive parallel line stays full at 13.3v. What could be the problem please? Could it be that the 2 batteries on the negative line draining to 10v are faulty? I have only used this setup for 2 days before noticing this as the inverter beeps low battery after 3 hours.
    Pls help.

    • @cleversolarpower
      @cleversolarpower  6 месяцев назад

      What happens if you switch the leads over? Check your wiring again. Are there any imbalances in the batteries? If so, charge every battery individually with a 12v charger and connect again.

  • @roygan5811
    @roygan5811 3 месяца назад

    Hi Nick, How did you calculate the 90 amp load ?

  • @jimnunally1
    @jimnunally1 3 месяца назад

    I have four 48v 30ah and two 48v 50ah LIFEPO4 batteries. All are connected to 4 lug busbars. In order to even out the draw from the difference capacities, do you have an alternate parallel wiring suggestion?

    • @cleversolarpower
      @cleversolarpower  3 месяца назад

      No. the draw will be based on voltage if they are all wired in parallel. So the voltage of every battery will be the same at all times.

  • @RobinMuric
    @RobinMuric 3 месяца назад

    I have purchased a 8000 wat 12v inverter. What kind of batteries should I buy to power it?

    • @cleversolarpower
      @cleversolarpower  3 месяца назад +1

      Yikes man, why did you get a 8,000W inverter on a 12V battery? Check my most popular video, how many batteries for a 3,000W inverter an repeat the same calculations.

    • @RobinMuric
      @RobinMuric 3 месяца назад

      @@cleversolarpower Thank you, I wanted to be sure that I could power a refrigerator, freezer, hot water tank and a kitchen stove, exc.

  • @1GREATDANE
    @1GREATDANE 22 дня назад

    Qty of 4 - 24 Volt 100amp hour batteries to a Buss Bar with 100amp Mbrf terminal fuses on each Battery for a 3000 watt 24 Volt Inverter and a 60 Amp Mppt Charge Controller.
    Do I Fuse the Inverter from the Buss Bar with 200 amp fuse to 4 / 0 Cables ?

    • @cleversolarpower
      @cleversolarpower  20 дней назад +1

      Indeed, you need a fuse from the busbar to the inverter. 3000W/24=125A*1.25 (safety factor)=156A. A 175A MEGA fuse or 200A fuse can be used. A cable that can carry 200A minimum is 2AWG welding cable (105°C insulation temp). Your charge controller needs a 75A fuse. A cable that can carry minimum 75A is 6AWG.

    • @1GREATDANE
      @1GREATDANE 20 дней назад

      @@cleversolarpower Thank You Nick

  • @wernerviehhauser94
    @wernerviehhauser94 23 дня назад

    connecting two batteries in different states of charge might set you up for a big surprise. If the batteries have high capacities, there will be high currents when the charge tries to equalize. Above 100Ah, apply a little caution when connecting full and empty batteries in parallel, especially if they do not have a BMS.

    • @cleversolarpower
      @cleversolarpower  23 дня назад

      Indeed. Better to charge them or discharge them before connecting.

  • @RobJamgo
    @RobJamgo 5 месяцев назад

    I have an AIMS LiFEPO4 100Ah battery and want to add in parallel another 100Ah battery. AIMs no longer makes its 100Ah battery. Can I add a 100Ah of another brand? How does the BMS work if batteries are not the same? Any other considerations? Looking at Litime 100Ah to add... thanks - oyur site is great!

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад

      Thanks 🙏, yes you can add another battery in parallel. You can even have different capacity batteries in parallel.

    • @RobJamgo
      @RobJamgo 5 месяцев назад

      @@cleversolarpower Thanks for quick reply - there should not be any issues with different battery monitoring systems?

  • @4115steve
    @4115steve 6 месяцев назад

    Do you need to worry about balancing when wiring batteries in series? Im on a facebook solar group there are mixed answers on this subject

  • @rb.tees2365
    @rb.tees2365 7 месяцев назад

    question??
    i have 50ah lifeo4 24V series connection assembled and 75ah lifeo4 24V same series assembled..i am planning to parallel to parallel this so i can get 125ah...now the question... is it possible to use 1BMS 100A in this 50ah and 75ah if i combined it in parallel

  • @nomanaftab2009
    @nomanaftab2009 4 месяца назад

    Can you guide please? How I will add a 120 ah battery to already four batteries of 105 ah connected in series. The voltage is 48v must for solar inverter

    • @cleversolarpower
      @cleversolarpower  4 месяца назад

      You cant. only if the 120Ah battery is 48V.

    • @Mueez_Edits
      @Mueez_Edits 4 месяца назад

      I want to add it in parallel, the voltage will remain the same, amperes will increase

  • @Milldog2023
    @Milldog2023 3 месяца назад

    So glad i found this page, im just about to hook up inverter and a ton of wet batteries i bought pre cov , i noticed one of the solar panels has a nick in the rear panel bit. I still ok to use? i have a pip 2424msxe brand new , So i have a feeling im gonna be loving this page for sure.

    • @cleversolarpower
      @cleversolarpower  3 месяца назад

      It's best to measure the solar panel output with a multimeter. there are several videos that show how.

  • @TERBANGFPV
    @TERBANGFPV 3 месяца назад

    i fly fpv mountain long range and use my diy 6s2p molicel liion.. and i wonder if i can combine my 6s2p 8400mah and 6s1p 4200mah (all the same molicel sell and type) because when i discharged them with my xt60 parallel connector to a discharger both were discharged at the same total mah (just like if they are wired directly as 6s3p). and then when i charged each 6s2p and 6s1p they were charged at the same total miliamp.. so is this means safe to parallel a 6s2p 8400mah and 6s1p 4200mah to fly? (my discharger only discharge at 6A vs cruise flying is around 15-25A constant.

    • @cleversolarpower
      @cleversolarpower  3 месяца назад +1

      Seems like it can because it will act like a 6S3P pack.

  • @parmeetsingh2381
    @parmeetsingh2381 7 месяцев назад

    i have two custom made 24v 100ah lifepo4 batteries made with 8 prismatic cells each. I used JK 100amp smart BMS. can these batteries be connected parallely? how BMS would handle the charging?

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад +1

      These can be connected in parallel. The BMS sees every battery individually. Because they are in parallel, they will be at the same voltage. One battery can charge with more current than the other, no problem.

    • @parmeetsingh2381
      @parmeetsingh2381 7 месяцев назад

      @@cleversolarpower thanks for explaining. Let me clear one more thing. i have two seperate custom made batteries EACH WITH A BMS. So there will be two batteries with two different BMSs. Still they can be connected?

  • @mortaneous
    @mortaneous 8 месяцев назад +1

    Great video. Very informative. Question though: I built a 24v system using two 12v 200ah LiFePO4 batteries in series. Now I plan to increase the capacity to 300ah by adding a 24v100ah LiFePO4 battery in parallel. Assuming I have all the correct breakers/fuses and wire sizes in place, what (if any) should I be looking out for in this set up? Is this a safe configuration?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +2

      Run the third battery from the busbar like the diagram i showed near the end of the video. It will run perfectly.

    • @mortaneous
      @mortaneous 8 месяцев назад +2

      I do have bus bars between the batteries and the inverter which I put there to facilitate addition of batteries in the bank. Thank you for confirming I'm on the right track!

    • @thetoolmat8632
      @thetoolmat8632 7 месяцев назад

      @cleversolarpower How many 100ah 12v batteries can i run on a 2000w Inverter? Is it up to 4 in parallel? Right now I have have 2 batteries and want to add a 3rd then a 4th when feasible.. thanks

  • @earthenergyhex
    @earthenergyhex 7 месяцев назад

    Great video, I learned alot

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад

      Thanks, make sure to subscribe so you don't miss out on future videos!

  • @laurentsosson1739
    @laurentsosson1739 5 месяцев назад

    Good morning
    I have 2 packs of Lifepo with the same voltage but
    1 is 24 volt 1120 AH and the other is 24 volt 200AH
    I would also like to put // both
    I don't know if a fuse is needed between the two?
    otherwise my converter is a 4000 watts to 24 volts
    what do you think about implementing // the 2 packs?
    busbars between the 2?
    THANKS
    laurent

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад

      You should wire batteries in parallel. I have videos about fuse and cable sizes, check them out on my channel.

    • @laurentsosson1739
      @laurentsosson1739 5 месяцев назад

      I wanted to put the 2 packs on a busbars with 2 BMS and then busbars on converter

  • @reginaldojimenez2646
    @reginaldojimenez2646 3 месяца назад

    I got 2 12v 200ah in parallel with a 3500 watt inverter is that inverter ok to use?

  • @nuteinselasingur3850
    @nuteinselasingur3850 14 дней назад

    Very nice said

  • @sadohjoseph3888
    @sadohjoseph3888 7 месяцев назад

    Thanks for your tutorial. Please How can I get 48V and range of 3820Ah to 4000Ah when connected in series and parallel

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад

      Thanks! Why do you need that big of a battery? A 48V 5kW server rack is 100Ah. So you need 40 server rack batteries. That's $50,000.

    • @sadohjoseph3888
      @sadohjoseph3888 7 месяцев назад

      @@cleversolarpower please can I talk to you privately via email?

  • @chukwudinmaikechukwu
    @chukwudinmaikechukwu 8 месяцев назад

    Is it advisable to charger the battery with the ac output of the inverter charger, i.e the ac current the inverter charger produced?

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад

      You can charge the battery with the solar input or through the ac input. The output is used to power loads.

  • @carscoffee5263
    @carscoffee5263 4 дня назад

    Ive used Lithium and lead acid charged simultaneously in parallel for atleast a decade. Its common for sailboaters to do it also. I use different voltage Lithium in series bc voltage is additive.. Direct dc to dc solar charging with no inverter, charge controller or bms.Thats probably 2 more things you'd tell us isnt feasible... Just because something isn't recommended doesn't mean it can't be done safely and be functional If you know what you're doing...

  • @calumlovett7661
    @calumlovett7661 8 месяцев назад

    Do you not need to worry about battery balancing as well? I would have though each pair of batteries in your diagram would need a balancer as they are in series? Can you confirm if batteries in series need fuses on each positive terminal or just the main out one?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +2

      Since the batteries are in parallel, they will balance themselves. The balancer inside each battery will take care of balancing the individual cells inside. Batteries in series don't need individual fuses. Just one at the positive lead.

    • @calumlovett7661
      @calumlovett7661 8 месяцев назад

      @cleversolarpower I thought the diagram had 2 off 100ah batteries in series with 2 off 280ah batteries in series with both series "banks" then in parallel?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      Ah, you are referring to the diagram. I don't think this will be a big problem. The BMS will regulate the individual cells of each battery. balancing happens when the battery is fully charged, so having the batteries fully charged from time to time will solve this problem of imbalance in a series connection. Every battery will balance to it's rated voltage independently. If the battery is cycled a lot at a high c-rate then this might become a problem.

  • @markpotter3057
    @markpotter3057 8 месяцев назад

    Hi there, mark here from Australia. I have two 135ah lithium batteries in parallel and two 300w panels in series . So I have 270ah and 600w of power going through the charge controller. Have I got that setup right or do you recommend another way if it’s an overkill. Kind regards, mark.

    • @markpotter3057
      @markpotter3057 8 месяцев назад

      Sorry I forgot to say I’m using a 2000w to 4000w pure sine wave inverter converter DC12v to AC240v unit

    • @markpotter3057
      @markpotter3057 8 месяцев назад

      Hi there I get the charge of the batteries thank you. When I send that charge to the inverter, how is that done please. 🤓🤓

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      600W/14.6=41A going to your batteries at max output.
      2000W/12V=167A -> ok for lithium.
      Check my video on sizing wires and fuses.

  • @john-j7e7e
    @john-j7e7e 6 месяцев назад

    i have two power queen 12 volt100amp batteries. i am connecting in parallel with a renogy 700 watt inverter.
    can i use 6awg wires to connect both batteries?

    • @cleversolarpower
      @cleversolarpower  6 месяцев назад

      Checkout my video about sizing wires. Then check my video about sizing fuses.

  • @ogunrinolatimothyoluseye4200
    @ogunrinolatimothyoluseye4200 Месяц назад +1

    Pls l want to use different amp battery for 1.5 inverter, I have 2 75A, and 1 pcs of 100A

  • @bupbup777
    @bupbup777 4 месяца назад

    Your videos are awesome!

  • @mirwanbaloch
    @mirwanbaloch 7 месяцев назад

    hi hello , i have two 12 volt 70 Ah battries and one big 12 volt battery of 120 ah , my solar inverter is of 24 volt and now how to connect these in series and parallel pls

  • @jamesalles139
    @jamesalles139 8 месяцев назад +1

    Personally, I would avoid mixing differing capacities with lead-acid chemistry. I believe that is following most manufacturers recommendations, also.

  • @arinzeosigwe
    @arinzeosigwe 7 месяцев назад

    So I have a question, I have a 24 volts inverter and from my calculations, 3 lead acid batteries of 200Ah will be enough for my daily usage.
    Now how do I go about this, can I connect two of the 200Ah batteries in parallel thereby giving me 400Ah at 12v then connect this to a single 200Ah battery in series to give me a 24v battery bank?
    If this can be done, what will the total battery bank capacity be.

    • @cleversolarpower
      @cleversolarpower  6 месяцев назад

      You cannot connect different capacity batteries in series. You can only use 2 batteries.

  • @user-rz3ro9lu6o
    @user-rz3ro9lu6o 4 месяца назад

    At the 5:00 mark of the video, you have shown that the load from the inverter, and all of the chargers (solar & battery charger), are all connected to the same buss bars, and therefore to the same "corners" of the battery array.
    I have 4x 6v lead acid batteries in a typical series/parallel arrangement. I was advised some time ago, that the +/- connections for the CHARGING circuit, should be at "opposite" corners of this battery arrangement, while the +/- connections for the LOAD circuit, should be at the opposing corners of the battery arrangement. So, the charge connections are at opposite corners compared to the load connections.
    How important is this? Your diagram is simpler and makes sense to me!

    • @cleversolarpower
      @cleversolarpower  4 месяца назад

      Good question. It doesn't really matter in your case (2S2P). I assume you were told to do so to limit the amount of lugs you have on one battery terminal. Now you have 2 but if you follow my diagram you would have 3. Max 3 are allowed.

    • @user-rz3ro9lu6o
      @user-rz3ro9lu6o 4 месяца назад

      @@cleversolarpower If however I wanted to add a shunt on the negative post, I would then be forced to insert at least a negative buss bar, correct? I believe that this is because the shunt needs to be between the negative battery post, and all 3 of the load / charger / solar controller.
      And if I need the negative buss bar, I figure might as well go ahead with a positive buss bar.
      thaanks,

  • @jhay_mstv6331
    @jhay_mstv6331 8 месяцев назад

    Clear! Thank you sir , I'll subscribe

  • @miroperinich2495
    @miroperinich2495 7 месяцев назад

    I am a qualified fitter for solar photovoltaic systems. I am interested in what would be the order of the budget for one system. What does it start from?

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад

      It depends on how much power you consume and how long you want the battery to last on cloudy days. off-grid is going to be more expensive than on-grid. But if the power company charges more than installing an off-grid system, then the choice is clear.

  • @MarkAkins-r5w
    @MarkAkins-r5w 3 месяца назад

    I have two lithium ion batteries for my e-bike hooked in parallel 48 volts they have different capacities what would happen if I took a 12-volt lithium-ion battery different capacitance and complete the circuit in series to my controller to make it a 52 volt power pack

  • @LotsaThingsNstuff
    @LotsaThingsNstuff 7 месяцев назад

    I have 8 batteries, should I do 2 sets of 4 to a bus bar?

  • @RS474
    @RS474 8 месяцев назад

    I must have missed the part where you explain what the Shunt is for?? Or is that in another video??

    • @rainerinedinburgh5807
      @rainerinedinburgh5807 8 месяцев назад +1

      The shunt is for measuring the current going into and out of the battery bank. That way the charge controller (or perhaps a separate capacity meter) can keep track of, and show you, how full the batteries are.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      Couldn't have said it better.

  • @electroumit
    @electroumit 8 месяцев назад

    Thank you.

  • @sinan1752
    @sinan1752 7 месяцев назад

    I wonder if its possible to charge 4 serial connected batteries(48v) with a 12v charger with a ballance wirering

    • @cleversolarpower
      @cleversolarpower  6 месяцев назад

      You can do that when there is no load attached. good for initially charging the batteries before commissioning them. But should not be done long term.

  • @simon359
    @simon359 8 месяцев назад

    I have two battery banks. Eight 12 V Battle Born Batteries in series parallel at 48 V. The next battery bank is four SOK 12 V batteries wired in series parallel, for 48 V.
    The only difference is that the Battle Born Batteries are 1C and the SOK are .5 C.
    I have them on separate shunts, because the battery voltage charging is slightly different.
    Both battery banks are run to a positive and negative busbar.
    I put each battery bank at their proper amp hours. On the Battle Born Batteries shunt I have 200 amp hours and for the SOK I have 100 amp hours. This gives me a total of 300 amp hours.
    The only thing I’m unsure of is whether to have my Victron Quattro 5000/48V inverter set at 300 amp hours?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +1

      Yes, I dont see a reason why not. Since you said they have different voltage charging, why not set both to the lowest recommended voltage voor charging, for example 57.6V instead of 58.4V. then you can use one shunt for the whole battery bank, and every battery is in the recommended range.

    • @simon359
      @simon359 8 месяцев назад

      @@cleversolarpower
      Using two different shunts, I can dial in the exact voltage recommended per manufacture, for each battery bank. There’s quite a bit of difference between each charge setting. 55.2 for SOK and 56.8 for BB. This gives me the ability to set the charge controllers for the best average. 🖖

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      Then i would set it at 55.2V, you are not going to 'waste' much capacity by lowering the voltage of your whole battery bank. And lithium likes not being charged all the way up to 100%.

  • @okoiiwara8407
    @okoiiwara8407 24 дня назад

    I have six 12v 220ah tubular battery I want to upgrade to a 48v system. How do I connect them

    • @cleversolarpower
      @cleversolarpower  23 дня назад

      4 in series. You have two batteries left over

    • @okoiiwara8407
      @okoiiwara8407 23 дня назад

      @@cleversolarpower what if I parallel the other 2battery

  • @COOSA6870
    @COOSA6870 5 месяцев назад

    How do I hook a lipo charger on 3- 100ah lipo phosphate batteries wired in parallel???

    • @cleversolarpower
      @cleversolarpower  5 месяцев назад

      Just the same as the wiring diagrams on the video

  • @rainerinedinburgh5807
    @rainerinedinburgh5807 8 месяцев назад +2

    I think you've made a mistake. You emphasize the importance of having the same series resistance in the charging wires. You correctly recommend a pair of bus bars from which the wires to all battery terminals are of equal length. But your alternative solution for 5 batteries does not achieve equal resistance. If you have five batteries with four red and four blue link wires as shown at 2:50, then for batteries 2, 3, and 4, the series resistance consists of two link wire resistances (counting from the points where the main red and blue cables first split). There are two blue links for battery 2, two red links for battery 4, and one red plus one blue for battery 3. So far, so good. But batteries 1 and 5 each have four link resistances (one red plus three blue, or three red plus one blue). Surely, for equality, the main red wire should go to battery 1 and the main blue wire to battery 5. That way each battery has four link resistances in series with it.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      Indeed, it doesn't have equal resistance. This is how I would wire it if I don't want to use a busbar.

    • @diyEVguy
      @diyEVguy 8 месяцев назад

      @rainerinedinburgh5807: Agreed. See also Victron Wiring Unlimited.

  • @Shadows_101
    @Shadows_101 7 месяцев назад

    Question. i got hold of 57 free batteries of 6volt 4,5Ah NiMH type of batterys .. Thats a lot of batteries.. i wish to make a giant powerbank in parallel connection .. Is there something i have to remeber? ... do i need thicker cables then the ones that already are on the batteries? how is it when i charge that many batteries in parallell ? do i need a super charger? or just use a normal charger that will just take much longer time?
    I also got a hold on 43 of 4 cells NiCd batteries with a voltage of 4,8 and they have 4,5Ah -- planned to make a 2nd powerpack with those. All batteries are only 3 years old and they are fully functional.. they had to be replaced because of strict rules on batteries that feed emergency light on ship .. they get replaced every 3 years even the law say 5 years.. guess shipping company just want to make sure their ok .. they have been maintain charged trough the years they been active.. and they only sometimes get used on test of the emergency light onboard.

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад

      The 57 batteries are not that big actually. Assuming they have 100% of their capacity left, it's only 1,500Wh. A little more than a 12V 100Ah battery which now cost $260. Your second battery is 928Wh, close to a 12V 100Ah battery. So would you rather spend a lot of time, money for a BMS and not knowing if it is safe than buying two 12V 100Ah batteries for $520? I think you know the answer.

  • @rehoye
    @rehoye 8 месяцев назад

    What value is there in isolating the batteries with shotky diodes?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      Never heard of it, so i assume nothing. Why do you think this is beneficial?

  • @Aphong10
    @Aphong10 3 месяца назад

    What if i want to charge it from a separate solar charge controller?

  • @jamesklingenberg9382
    @jamesklingenberg9382 6 месяцев назад

    Good to know. Thanks.

  • @humphreymambwe7959
    @humphreymambwe7959 4 месяца назад

    We're can I buy the base ball connector

  • @SamCarleton
    @SamCarleton 8 месяцев назад

    Last summer I bought a lithium battery and want to purchase another one and hook them in series, is that safe?

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +1

      Yes, just be aware of balancing issues. Check my video about batteries in series.

    • @SamCarleton
      @SamCarleton 8 месяцев назад

      @@cleversolarpower thank you. I was going to use a battery balancer

  • @motherteresakondapalli1194
    @motherteresakondapalli1194 2 месяца назад

    Hi nick i have 20000AH battery with 59v soc is100% and 44v battery and soc is 0% i want to transfer the charge from one another with 80AH by charging cable of 100AH can you sole this give me the detailed explanation practically is it possible

    • @cleversolarpower
      @cleversolarpower  2 месяца назад

      You have to charge or discharge the batteries and then you can connect them. They have to be the same chemistry and be at the same state of charge.

  • @ssekyanzirobert9401
    @ssekyanzirobert9401 7 месяцев назад

    What's the best way to wire 3 solar batteries in parallel ?

  • @christiangusy1246
    @christiangusy1246 8 месяцев назад

    Hello. Your books are no more available. What's the problem ?
    Thank You.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +1

      It has always been available on Amazon.com

    • @christiangusy1246
      @christiangusy1246 8 месяцев назад

      @@cleversolarpower thank You for your rapid answer.
      I wish You a good day. Chris

  • @sportsupdate1413
    @sportsupdate1413 6 месяцев назад

    Is this possible? = 2 batteries 12V 100AH each, connected in SERIES (Result: 24V 100AH). And after that this will be connected in PARALLEL with 1 battery 24V 100AH (Result: 24V 200AH). Thank you!

  • @diyjohn2197
    @diyjohn2197 2 месяца назад

    How to wire 12 6volt lead acid battery for load and charge 24volt system

  • @darrylm3627
    @darrylm3627 7 месяцев назад

    😄👍Good Stuff, Great Tips

  • @dougiee6589
    @dougiee6589 8 месяцев назад

    This is good as for me

  • @shermanramsingh7898
    @shermanramsingh7898 4 месяца назад

    how do you connect enough EP3 Cube to give you a battery bank of 350kw

    • @cleversolarpower
      @cleversolarpower  4 месяца назад

      Easy, just divide by the power capacity of one battery which is 3.3kWh

    • @shermanramsingh7898
      @shermanramsingh7898 3 месяца назад

      @@cleversolarpower so what about the hybrid stacks of 19.9 kwh per ...how many stacks can you connect in series

  • @josepeixoto3384
    @josepeixoto3384 7 месяцев назад

    That's nice,but I do mix Li and Lead-acid, in parallel ; they work perfectly together, for 1.5 years now, and Lead-Acids need no BMS,only the Li, lifepo4, do.

  • @ivanwayne2507
    @ivanwayne2507 7 месяцев назад

    Contemplating the following set up: adding 4 identical 100 amp Li batteries-3 will be in series for a 36 volt trolling motor. 1 will power an audio amp an isotherm 12 volt fridge. I will have a NOCO Marine 4 pole charger when plugged into shore power-thinking of charging when running motors with a DC-DC charger. Looking at the Vectran XS. Can I charge all 4 batteries with this DC-DC charger if I use a busbar? Thanks. Your videos are super helpful

    • @cleversolarpower
      @cleversolarpower  7 месяцев назад

      Thanks for your sub! So your three batteries will run the trolling motor, and one battery will run a 12V fridge? Ideally, you need a 12V charger and a 36V charger. However, you can also charge the three 12V batteries if you manually switch them when one is full. However, this is not practical, so you need a separate 36V charger.

    • @ivanwayne2507
      @ivanwayne2507 7 месяцев назад

      @@cleversolarpower Sort of: three of the batteries in series to run the trolling motor while the 4th one would be a house battery. Each battery will have a shore power charging from a 12 volt Noco Marine charger that will individually charge each battery as they are needed. When I am not on shore power I am wanting to charge the batteries with a DC-DC charger using a busbar. Not sure if the DC-DC charger will do that properly or do I need 4 DC-DC chargers

  • @Jon-fs2zj
    @Jon-fs2zj 8 месяцев назад

    What if you wanted to charge 7 batteries go two groups 3 and 4?

  • @sailingforeverautumn
    @sailingforeverautumn 4 месяца назад

    You say you can't mix batteries of different chemistry. Yet most modern boaters have a hybrid bank, with both AGM and LiFePo4 batteries wired together in parallel. How come?

    • @cleversolarpower
      @cleversolarpower  4 месяца назад

      You can, but I don't recommend people do it. It gets complicated quickly. If you still have some good lead acid batteries, then yes, maybe. But now lithium is cheaper than lead acid by far. So why still use lead acid anyway?

    • @sailingforeverautumn
      @sailingforeverautumn 4 месяца назад

      @@cleversolarpower Well for instance if your boat engine normally charges your AGM battery bank, which you have for engine starting and instruments, but your lithium bank which is a house bank also gets charged by the alternator, the alternator can overheat as lithiums can take much more power than an AGM.
      There are DC to DC chargers, but they are expensive and adding one more layer of complexity into something that is in reality very simple.
      In order to avoid having to completely rewire, or rewire for two systems, wire the LiFePo4 batteries in parallel with the AGM's, the AGM's take charge from the alternator but the lithiums suck that charge out of the AGM's at a much slower rate. That way all batteries get charged, and the AGM's and Lithiums complement each other, while retaining redundancy. Thousands of boaters have been doing this for a very long time.

  • @taiwomathew8969
    @taiwomathew8969 8 месяцев назад

    How can I access your e-books

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад

      You get get it on amazon or on my website in the 'shop' section.

  • @grahamjohnbarr
    @grahamjohnbarr 4 месяца назад

    No, I have the right sizes. What I want to know is the wires coming from the Controller connect to which Battery terminals. Then the wires going from the Battery to the Inverter are connected to which Terminals on the Battery.
    I have four 300W panels connected to the Controller. Then from the Controller to the Battery's. Then from the Battery's to the Inverter. As it should be.
    I want to use the fan model as in the "Better." You have all the Positive Leads connected to a single point then a wire going "out" to the Inverter?
    All the Negative Terminal wires connect to a single point, then a wire going out to the inverter from that point, but no diagram of the Negative wire coming in from the Controller.
    All the Positive Terminal wires also connect to single Positive point then a wire going out to the Inverter from that point, but no diagram of the Positive wire coming in from the Controller.

  • @louf7178
    @louf7178 8 месяцев назад

    I trickle charged two batteries in parallel, but find this not good enough. The difference of conditions leads me to believe the weaker battery undercharges and therefore could sulfate. Therefore, I individually "top" them off.

    • @dnomyarnostaw
      @dnomyarnostaw 8 месяцев назад

      I presume they are lead acid? You didn't say.
      He seems to think all examples have s battery management system.

  • @grahamjohnbarr
    @grahamjohnbarr 4 месяца назад

    I need to know the wiring "in" from the Controller, then the wiring "out" to the Inverter. No-body shows that.

    • @cleversolarpower
      @cleversolarpower  4 месяца назад +1

      I have made videos about selecting wire size if that's what you mean.

    • @grahamjohnbarr
      @grahamjohnbarr 4 месяца назад

      @@cleversolarpower No, I have the right sizes. What I want to know is the wires coming from the Controller connect to which Battery terminals. Then the wires going from the Battery to the Inverter are connected to which Terminals on the Battery.
      I have four 300W panels connected to the Controller. Then from the Controller to the Battery's. Then from the Battery's to the Inverter. As it should be.
      I want to use the fan model as in the "Better." You have all the Positive Leads connected to a single point then a wire going "out" to the Inverter?
      All the Negative Terminal wires connect to a single point, then a wire going out to the inverter from that point, but no diagram of the Negative wire coming in from the Controller.
      All the Positive Terminal wires also connect to single Positive point then a wire going out to the Inverter from that point, but no diagram of the Positive wire coming in from the Controller.

  • @davemac521
    @davemac521 6 месяцев назад

    Know your battery chemistry.batteries should always be within a specific voltage when connectin in parallel or serial. Lithium batteries should always be fully charged and within .2 tenths of chage difference.

  • @joemaxxcapri1799
    @joemaxxcapri1799 7 месяцев назад

    I have only 3 Agm

  • @mINGzTH
    @mINGzTH 7 месяцев назад

    I would like to be clear. Parallel different capacity batterries is ok to do or not?

  • @davemac521
    @davemac521 6 месяцев назад

    Never install batteries of different ratings in any battery bank. The bank will not equalize and the lower capacity battery will reduce the capacity of the larger batterie. Reducing over all capacity of the entire battery bank over time.

    • @cleversolarpower
      @cleversolarpower  6 месяцев назад +1

      Like I said in the video, you can parallel different capacity batteries.

  • @johnbrown6189
    @johnbrown6189 8 месяцев назад

    This expiation is not correct at all. If the voltage rating of the batteries is the same even though they are different capacity batteries they will supply the same current to the load.

    • @cleversolarpower
      @cleversolarpower  8 месяцев назад +1

      No, try it yourself.

    • @rk_bhartiya
      @rk_bhartiya 7 месяцев назад

      Nooooo

    • @johnbrown6189
      @johnbrown6189 7 месяцев назад +1

      I don't need to. My statement is correct. Try looking at it like this. Using a 10L (10AH bat) tank, 5L(5AH bat) tank, 5mm tee hose where the tanks are connected and the third end goes to a valve then to atmosphere. The tanks are sitting in such a way that the water levels are at the same height. Now open the valve water will drain from both tanks equally same as in batteries. @@cleversolarpower