Thank you for sharing. I think this is an attractive way for the general DIY hobbyist to get a quick observation on individual cells, without getting too scientific about it. Establishing a thresh-hold of 280-300 milli ohms seems reasonable, despite the meter's high frequency output. After all, you're establishing RELATIVE values, in contrast to established values on a specifications chart. I commend your practical approach to this measurement technique.
Hey thanks for the shout out and VERY interesting idea. At the end of the day a relative reading is what you would require. The key detail here is how easily can this circuitry be integrated with our current setup of a switching charging and discharging setup. Something like a DC Load method would be so much simpler although a capacitor is omitted from the circuit. My understanding of an impedance circuit is limited but there is loads of Arduino based info for battery impedance. I'd love to see cells with known impedance and see how this compares to your method. Follow up video? I hope so!!!
Just watched your latest video & I see that BatLab Kickstarter is now fully funded. I guessing that the charge/discharge/recharge cycle in the grid will be around 6 hours per cell, so if there's some way to reject cells very early on in the process (i.e. before they get loaded into the grid) then it should significantly increase the throughput.... The DC Load method is definitely the best and most accurate way to measure, but injecting a square wave and measuring the ramp-up/ramp-down times (which is how the ESR meter works) can give a very quick indication of a high internal resistance. I'll have a play around a little more this evening to see how sensitive this is to cell voltage... I'm guessing that as long as the cell in in the long-flat part of the discharge curve (3.65v to 4.0v) the readings should be pretty consistent. Cheers!!
Evening Jim, so using this method you can hopefully get indicative figures in say 20 seconds per cell. I think that if you did this as a precheck it would be quite good at cutting out the real dross from the more time consuming charge/discharge cycle. I would assume that the discharge process will also take in to account the discharge at several loads to get some idea of what the resistance of the cell is as well as any temp rise per cell under these loads
Is there some nuance that wasn't explained regarding the meter? I tried this at 1kHz as well as 100kHz and it gave me results in the Mohm range and charged the capacitor
Hi Ted - I'm not sure what brand the ones in the box are - they're unlabeled... It was Panasonic 3400mAh cells which replaced them and increased the bike's range by about 50%. Hope all is well with you. Cheers!!
Hi Alex - I was using a 2500uF, 50V rated capacitor when I made this video - I purposefully chose a large sized capacitor because I wanted to be sure that the internal resistance of the capacitor would be fairly low. I don't believe the actual values of the capacitor matter though.. it's mostly just there to block DC, so just use any capacitor with a low ESR. Hope that helps. Cheers!!
That MESR-100 Meter is not 10 pound but 40 pounds. your results won't be accurate at all. but you will get a really rough idea, i advise you to get yourself internal battery resistance tester if you got that many batteries so you make a good battery pack, and match all internal resistance.
Yes - you could measure any kind of battery in this way. There's no need to add an extra resistor into the circuit as the tester is designed to work with very load resistances (micro-ohms) anyway. In the time since I made this video, I've bought myself a LiPo charger which can measure cell resistance - The values that charger reports are very close to the values I get using the technique in this video, so it seems to be a valid approach to test cells in this way. Cheers!!
Thank you very much for your quick reply, nice video and very informative. I am pretty sure it will solve many doubts on how to measure ESR on batteries a simple way.
i have LiitoKala Lii-500 when is better to measuring internal resistance ,when is full charged or when is discharged ? it is very different value like 10-90
The slotted testers are never a reliable way to test IR. How you place the cell on the contacts makes a huge difference for every reading and the resistance of the parts in series with the circuit must be taken into account. Opus says to deduct 65mohm from their reading.
Hi jim can u help me with my micro hdmi 14 mpx ;( i bouth 1 of this wokr on usb pc perfecto but direct hdmi to hmdi monitor or tv dont show video ;( can u helpt me ?
Dear friend, when i measure a battery (18650 for exatly) with multimeter in continuity mode, this sounds but no resistance is showed and the screwdriver blinking what is happend? Thank you so much for everything help
Bit late 1 year later but your meter applies its own voltage when measuring resistance and is detecting a voltage (from the cell) interfering with its own test. You cannot continuity test a cell unless it's a faulty shorted one of course.
dont know if you guys cares but if you are bored like me during the covid times then you can watch pretty much all the latest series on InstaFlixxer. I've been binge watching with my gf recently :)
MUCH easier to just buy a Analysing charger. The cheapest one is the OPUS BT-C100 which costs USD$15. Measures capacity by Charge (max 2A) and Discharge (1A). Measures Internal Resistance during the test, but also has a dedicated Resistance test mode which takes about 10 seconds per battery www.gearbest.com/chargers/pp_300470.html
Always knew that they were junk, but amazingly the did once store their advertised capacity. I've certainly seen worse ones (such as anything claiming >3400mAh capacity which are normally about 1200mAh). Thanks for taking the time to comment. Cheers!!
The capacitor is not being charged at all. It is being driven with an AC signal from the capacitance tester, with the battery acting as a series resistance.
@@ThingsWhichArentWork You mentioned at the beginning of the video that your meter discharges the capacitor before taking a measurement. This means that by inserting the batter the meter will again discharge the capacitor: to the battery voltage! But you have it backwards! Ouch!
Thank you for sharing. I think this is an attractive way for the general DIY hobbyist to get a quick observation on individual cells, without getting too scientific about it.
Establishing a thresh-hold of 280-300 milli ohms seems reasonable, despite the meter's high frequency output. After all, you're establishing RELATIVE values, in contrast to established values
on a specifications chart. I commend your practical approach to this measurement technique.
Below 270-280mR he say;s is good if you want a quick answer. My new inr18650's are 20-30mR. Myself I feel like less than 150mR would be ok.
Hey thanks for the shout out and VERY interesting idea. At the end of the day a relative reading is what you would require. The key detail here is how easily can this circuitry be integrated with our current setup of a switching charging and discharging setup. Something like a DC Load method would be so much simpler although a capacitor is omitted from the circuit. My understanding of an impedance circuit is limited but there is loads of Arduino based info for battery impedance.
I'd love to see cells with known impedance and see how this compares to your method. Follow up video? I hope so!!!
Just watched your latest video & I see that BatLab Kickstarter is now fully funded. I guessing that the charge/discharge/recharge cycle in the grid will be around 6 hours per cell, so if there's some way to reject cells very early on in the process (i.e. before they get loaded into the grid) then it should significantly increase the throughput.... The DC Load method is definitely the best and most accurate way to measure, but injecting a square wave and measuring the ramp-up/ramp-down times (which is how the ESR meter works) can give a very quick indication of a high internal resistance. I'll have a play around a little more this evening to see how sensitive this is to cell voltage... I'm guessing that as long as the cell in in the long-flat part of the discharge curve (3.65v to 4.0v) the readings should be pretty consistent. Cheers!!
Evening Jim, so using this method you can hopefully get indicative figures in say 20 seconds per cell. I think that if you did this as a precheck it would be quite good at cutting out the real dross from the more time consuming charge/discharge cycle.
I would assume that the discharge process will also take in to account the discharge at several loads to get some idea of what the resistance of the cell is as well as any temp rise per cell under these loads
Is there some nuance that wasn't explained regarding the meter? I tried this at 1kHz as well as 100kHz and it gave me results in the Mohm range and charged the capacitor
I believe you are onto something.
You have a full box of 18650 Panasonic slightly used? In the USA they don't sell them but from what I read they do at vapor e-cig stores.
Hi Ted - I'm not sure what brand the ones in the box are - they're unlabeled... It was Panasonic 3400mAh cells which replaced them and increased the bike's range by about 50%. Hope all is well with you. Cheers!!
An elegant way. Thank you for that.
I was wondering the size of capacitor you had on your test on the video, thank you for the info on measuring the resistance on 18650s.
Hi Alex - I was using a 2500uF, 50V rated capacitor when I made this video - I purposefully chose a large sized capacitor because I wanted to be sure that the internal resistance of the capacitor would be fairly low. I don't believe the actual values of the capacitor matter though.. it's mostly just there to block DC, so just use any capacitor with a low ESR. Hope that helps. Cheers!!
Jim Conner Thank you very much.
That MESR-100 Meter is not 10 pound but 40 pounds. your results won't be accurate at all. but you will get a really rough idea, i advise you to get yourself internal battery resistance tester if you got that many batteries so you make a good battery pack, and match all internal resistance.
Can you test any battery (12v AGM/Lead Acid) with this method? . Adding a resistor may lower any risk of damaging the tester?
Yes - you could measure any kind of battery in this way. There's no need to add an extra resistor into the circuit as the tester is designed to work with very load resistances (micro-ohms) anyway. In the time since I made this video, I've bought myself a LiPo charger which can measure cell resistance - The values that charger reports are very close to the values I get using the technique in this video, so it seems to be a valid approach to test cells in this way. Cheers!!
Thank you very much for your quick reply, nice video and very informative. I am pretty sure it will solve many doubts on how to measure ESR on batteries a simple way.
i have LiitoKala Lii-500 when is better to measuring internal resistance ,when is full charged or when is discharged ? it is very different value like 10-90
Internal resistance should be measured when the battery is fully charged.
The slotted testers are never a reliable way to test IR. How you place the cell on the contacts makes a huge difference for every reading and the resistance of the parts in series with the circuit must be taken into account. Opus says to deduct 65mohm from their reading.
Hi jim can u help me with my micro hdmi 14 mpx ;( i bouth 1 of this wokr on usb pc perfecto but direct hdmi to hmdi monitor or tv dont show video ;( can u helpt me ?
Dear friend, when i measure a battery (18650 for exatly) with multimeter in continuity mode, this sounds but no resistance is showed and the screwdriver blinking what is happend?
Thank you so much for everything help
Bit late 1 year later but your meter applies its own voltage when measuring resistance and is detecting a voltage (from the cell) interfering with its own test. You cannot continuity test a cell unless it's a faulty shorted one of course.
what capacitor did you use-capacitance and volts
2500uF 50v random capacitor which was lying around on a shelf. Cheers!!
danke wel!!!
This is cool even though I have no idea what is going on :) Wish I know more about electrical theory :) Or whatever it would be called :)
dont know if you guys cares but if you are bored like me during the covid times then you can watch pretty much all the latest series on InstaFlixxer. I've been binge watching with my gf recently :)
@Lyric Nash Yup, I have been watching on InstaFlixxer for since november myself =)
MUCH easier to just buy a Analysing charger. The cheapest one is the OPUS BT-C100 which costs USD$15. Measures capacity by Charge (max 2A) and Discharge (1A). Measures Internal Resistance during the test, but also has a dedicated Resistance test mode which takes about 10 seconds per battery www.gearbest.com/chargers/pp_300470.html
by now I assume youve found the trustfire cells are junk
Always knew that they were junk, but amazingly the did once store their advertised capacity. I've certainly seen worse ones (such as anything claiming >3400mAh capacity which are normally about 1200mAh). Thanks for taking the time to comment. Cheers!!
Haha scrolled for this. Had me at "this trustfire one hasn't been used so should be OK"
Thats literally the only time they're OK 😂
Your capacitor is being charged in reverse! You will ruin it unless you reverse your battery.
The capacitor is not being charged at all. It is being driven with an AC signal from the capacitance tester, with the battery acting as a series resistance.
@@ThingsWhichArentWork You mentioned at the beginning of the video that your meter discharges the capacitor before taking a measurement. This means that by inserting the batter the meter will again discharge the capacitor: to the battery voltage! But you have it backwards! Ouch!