I would beef up the series cable going from one row of cells to the other, so that it doesn't have higher resistance. One of the virtues of those CALB cells is the cases they come in. You have to REALLY abuse them to get those cases to bulge. I'm not sure compression was necessary. In fact, for most home "powerwall" or DIY power station builds, compression of cells isn't indicated because they are rarely pushed hard, or even moderatly hard. The final thing I'll mention is those cells probably have at least 90% of their original capacity, or over 160AH. Since a 48v nominal pack is really rated at 51.2 volts, multiply that times the additional 62 amp-hours of capacity you installed, and you've got roughly 3,100 watt-hours worth of additional capacity, over what you would get from a new, 100AH, server-rack battery. That is substantial and should not be understated. In the end, you got around 8,200 watt-hours instead of 5,1000 watt-hours, for the same cost or less. That's very cool.
Thanks for the comment I agree, not a bad idea I may double up the crossover cable, I have more wire , there not compressed very tightly, when I got the cells a few had slight swelling but I wouldn’t consider it too bad, I really need to do an actual capacity test in the future, I try and under rate for worst case scenarios. Overall I’m very happy with this battery it’s performed very well, between this and my server rack battery I can run my mini split at full power for around 12 hours on battery alone.
Thank you for sharing your knowledge. It would be hehelpfulf you put some links to make sure I buy the exact equipment you are usi.e., ie. BMS, Wire, etc.
It looks like you are in the USA. Home depot sells 1/8 by 1 inch aluminum flat bar 48 inches long for 12 dollars. I know aluminum has about 3x the resistance of copper, but a 1/8 by 1 inch bar has much more than 3 times the area of 4awg copper. Using aluminum bar between your battery terminals would make it much simpler to construct your battery packs. You can also get one of those drill and tap bits to tap the aluminum bar, then just put in a screw and wrap the wire around it, or crimp an end on if you want to be fancy. You can put a piece of tape on the aluminum to make it safe, and the tape can cover the bolt too for safety.
I was wondering about using aluminum, but was worried about the resistance, however a lot of premade batteries use them as busbars already, I may try it in a future build!
Hi there! I'm a total electronics newb. I did however understand most of what you did, and why you did it. But I haz newb questions! You made a 48v battery bank. I see them frequently being used in off-grid setups, or just for back-up storage. I have however also binge-watched some vids, where people try making their own generator, to fill up their 48v powerbank. Several of those tryed to convert a car alternator to "somehow" output 48v. If I understood this build process correctly, you could have made 4 batteries of 12v, and connect them in parallel, to get the same amount of stored power. From my understanding, a good solar controller charger thingy (MPPT?) can also just charge up a 12v battery bank. -What was YOUR reasoning for going 48v? -If you'd have a 12v DIY made generator, would it have made more sense to go 12v battery banks? (converting an alternator/electro motor to output 48v, seems complicated) -What are the downsides of having 12v battery banks in paralel? Thnx for your reply!
Hello thanks for the comment, the main reason to use 48 volt is for larger loads, most large inverters are 48 aswell. If you have a 1000 watt load, on 12 volts thats 83 amps, means you need really thick, good cable, connections, stuff like that. The same load on 48 volt requires only 20.8 amps, 1/4 of the current. You can use smaller cables, less heat and that kind of stuff, and thats only for 1000 watts, it gets worse with bigger loads. I have both 12 volt and 48 volt systems, 12 volt is cheaper to build, and more beginner friendly, 48 is easier to scale up for large loads. Both work great, just depends on what your goals are. I hope this helps good luck!
If you connect four 12v batteries in parallel...you have a 12v battery, with a larger total capacity, in terms of amp-hours. When you connect in parallel, the voltage stays the same and the amp-hours adds up. When you connect in series, the amp-hours remains the same, but the voltage adds up. If you connect four 12v batteries in series, you get 48 volts (nominal). What was done in this video is he connected 16 battery cells in series, each with a 3.2v nominal rating, to create a dedicated 48 volt battery. He did make any 12v batteries or connect 12v batteries in series. A 12v battery is four 3.2v cells in series. He connected 16 of those cells in series to make a straight 48v battery.
I know it has been a while since you posted this great video. I have a quick question what charging settings did you use for this setup? 58.4v charging and 54.4 float? I have this identical setup.
Do it yourself home built lithium battery packs should be regulated, imagine someone in a block of high rise flats copying this video and make a mistake.
regulated as in controlled? You picked a very specific scenario to have very broad regulation instead of suggesting regulation for your very specific scenario. Imagine someone in their house trying to fix their gas tank by only emptying the tank but leaving the very combustible gasoline vapor within the tank. Let's require certification for people fixing their own cars.
I just got 5 for a 16v car system. 375 and 50 shipping to the same state as them. They have the pdf sheet to show you internal resistance and capacity for your specific cells
@@Mikebuildss Only sucks if you think to much about it. Getting it done and posting the video though! These are really awesome, the best terminals. I used an impact driver nearly full blast and they stood the test. The lev60f japanese cells have plastic all around the terminal that shatters easily. Haha btw so far I see 3 cats. Yep. I am sure you have a good laugh and smile each day with them.
@@Mikebuildss Oh hey about how you used m8 bolts. I found m8 threaded studs and a seperate nut works much better. You can seat the nut down the stud as far as you need. I also didn't have buss bars but a roll of 18awg dead soft copper wire. I wound around the studs under the nut enough to have 3/4 ounce of copper like 19 winds around then tightened with the nut. Really easy to fabricate parallel or series wiring too.
I would beef up the series cable going from one row of cells to the other, so that it doesn't have higher resistance. One of the virtues of those CALB cells is the cases they come in. You have to REALLY abuse them to get those cases to bulge. I'm not sure compression was necessary. In fact, for most home "powerwall" or DIY power station builds, compression of cells isn't indicated because they are rarely pushed hard, or even moderatly hard. The final thing I'll mention is those cells probably have at least 90% of their original capacity, or over 160AH. Since a 48v nominal pack is really rated at 51.2 volts, multiply that times the additional 62 amp-hours of capacity you installed, and you've got roughly 3,100 watt-hours worth of additional capacity, over what you would get from a new, 100AH, server-rack battery. That is substantial and should not be understated. In the end, you got around 8,200 watt-hours instead of 5,1000 watt-hours, for the same cost or less. That's very cool.
Thanks for the comment I agree, not a bad idea I may double up the crossover cable, I have more wire , there not compressed very tightly, when I got the cells a few had slight swelling but I wouldn’t consider it too bad, I really need to do an actual capacity test in the future, I try and under rate for worst case scenarios. Overall I’m very happy with this battery it’s performed very well, between this and my server rack battery I can run my mini split at full power for around 12 hours on battery alone.
Thank you for sharing your knowledge. It would be hehelpfulf you put some links to make sure I buy the exact equipment you are usi.e., ie. BMS, Wire, etc.
Yes i agree i will start adding some useful links!
It looks like you are in the USA. Home depot sells 1/8 by 1 inch aluminum flat bar 48 inches long for 12 dollars. I know aluminum has about 3x the resistance of copper, but a 1/8 by 1 inch bar has much more than 3 times the area of 4awg copper. Using aluminum bar between your battery terminals would make it much simpler to construct your battery packs. You can also get one of those drill and tap bits to tap the aluminum bar, then just put in a screw and wrap the wire around it, or crimp an end on if you want to be fancy. You can put a piece of tape on the aluminum to make it safe, and the tape can cover the bolt too for safety.
I was wondering about using aluminum, but was worried about the resistance, however a lot of premade batteries use them as busbars already, I may try it in a future build!
Hi there! I'm a total electronics newb. I did however understand most of what you did, and why you did it. But I haz newb questions!
You made a 48v battery bank. I see them frequently being used in off-grid setups, or just for back-up storage. I have however also binge-watched some vids, where people try making their own generator, to fill up their 48v powerbank. Several of those tryed to convert a car alternator to "somehow" output 48v.
If I understood this build process correctly, you could have made 4 batteries of 12v, and connect them in parallel, to get the same amount of stored power. From my understanding, a good solar controller charger thingy (MPPT?) can also just charge up a 12v battery bank.
-What was YOUR reasoning for going 48v?
-If you'd have a 12v DIY made generator, would it have made more sense to go 12v battery banks? (converting an alternator/electro motor to output 48v, seems complicated)
-What are the downsides of having 12v battery banks in paralel?
Thnx for your reply!
Hello thanks for the comment, the main reason to use 48 volt is for larger loads, most large inverters are 48 aswell. If you have a 1000 watt load, on 12 volts thats 83 amps, means you need really thick, good cable, connections, stuff like that. The same load on 48 volt requires only 20.8 amps, 1/4 of the current. You can use smaller cables, less heat and that kind of stuff, and thats only for 1000 watts, it gets worse with bigger loads. I have both 12 volt and 48 volt systems, 12 volt is cheaper to build, and more beginner friendly, 48 is easier to scale up for large loads. Both work great, just depends on what your goals are. I hope this helps good luck!
If you connect four 12v batteries in parallel...you have a 12v battery, with a larger total capacity, in terms of amp-hours. When you connect in parallel, the voltage stays the same and the amp-hours adds up. When you connect in series, the amp-hours remains the same, but the voltage adds up. If you connect four 12v batteries in series, you get 48 volts (nominal). What was done in this video is he connected 16 battery cells in series, each with a 3.2v nominal rating, to create a dedicated 48 volt battery. He did make any 12v batteries or connect 12v batteries in series. A 12v battery is four 3.2v cells in series. He connected 16 of those cells in series to make a straight 48v battery.
making it look easy great video
I know it has been a while since you posted this great video. I have a quick question what charging settings did you use for this setup? 58.4v charging and 54.4 float? I have this identical setup.
Correct, I think I have cell high voltage to trip right at 3.65 per cell, my system seems to float around 56 volts fully charged.
I use the system everyday so these get used regularly
Thank you for the answer. I am getting closer to finishing my build. This really helps. Keep up the great work!
great video
Great video Mike! Just curious after 10 months if you are still happy with your Daly BMS ... would you still recommend it? Thanks!
Yes it’s used almost everyday have not had any issues!
Oh my lifepo4's.
Do it yourself home built lithium battery packs should be regulated, imagine someone in a block of high rise flats copying this video and make a mistake.
Safety is key! Hire a professional if your unsure of what your doing!
regulated as in controlled? You picked a very specific scenario to have very broad regulation instead of suggesting regulation for your very specific scenario. Imagine someone in their house trying to fix their gas tank by only emptying the tank but leaving the very combustible gasoline vapor within the tank. Let's require certification for people fixing their own cars.
You can get brand new for 75 dollars each at battery hookup.
I just got 5 for a 16v car system. 375 and 50 shipping to the same state as them.
They have the pdf sheet to show you internal resistance and capacity for your specific cells
I saw that, sucks cause that’s about what I paid for these lol but they did not have them new when I built this pack, there great cells
@@Mikebuildss Only sucks if you think to much about it. Getting it done and posting the video though!
These are really awesome, the best terminals. I used an impact driver nearly full blast and they stood the test. The lev60f japanese cells have plastic all around the terminal that shatters easily.
Haha btw so far I see 3 cats. Yep. I am sure you have a good laugh and smile each day with them.
@@Mikebuildss Oh hey about how you used m8 bolts. I found m8 threaded studs and a seperate nut works much better. You can seat the nut down the stud as far as you need. I also didn't have buss bars but a roll of 18awg dead soft copper wire. I wound around the studs under the nut enough to have 3/4 ounce of copper like 19 winds around then tightened with the nut. Really easy to fabricate parallel or series wiring too.