Headway 38120 (BatteryHookUp)capacity testing

Capacity checking 12 (used) 38120 cells from batteryhookup

[kennedy]

When I decided to make my e-bike my primary vehicle I discovered battery hookup. Their pricing seemed too good to be true. I purchased 15 36v 4.4ah (samsung cells) packs that were for hoverboards. I absolutely love these guys! They are hands down my first go to when it comes to lithium cells. They were honest and timely. I'm telling you it was the best deal I've ever gotten. They are the best in used cells and packs. And they are as honest as anyone in the battery business! If your on the fence I hope this helps u make the right choices. I've been had by throttle manufactures and bldc hub motor manufactures. But never in batteries because these guys are the best.

[paul_dz]

Although this was posted some time ago, it's a great reference for headways (really any cells in theory) - I really appreciate the note on the pack builder - I think this is overlooked on a lot of similar battery building videos.

[kswis]

It is def hit n miss with battery hookup, I have been gathering now and then buying the same used cells. The majority of the 140 cells I've purchased test 70%-85% however the last batch of 12 ALL test at 8.2-8.4 ah. Sure wish they were all used and testing that well. I digress thanks for sharing

[Blue-Collar-Radio]

I will definitely follow along with your build. Well done 👏

[lilman]

I do the opposite. Drain the batteries into a known good pack that needs charging anyways. Once they’re all all discharged, I charge them up separately or in groups of 4 (if I’m working with more than 48 or so cells) to measure the capacity that I have and configure accordingly

[jimmio]

Just a word of caution... if you wire them all in parallel like you do for charging? You can have a really bad time... These cells can deliver **EIGHT HUNDRED AMPS** when shorted... half that gives you 400A of charging current for any battery that is lower voltage... and the cells are only rated for 200A continuous current draw. This means you damage both the higher voltage cells by drawing 400-800A, and that you damage the lower voltage cells by charging 400-800A when they're rated for 80A charge continuous.

[viciousvigilante]

So even though the cells in the end are all going in the same place, does it actually matter in the order that you set them in when you create the headway bank?

[Bigislandguy]

Battery hookup says the Ah rating is discharging 1.6a to 2.5volts. I found this out on my Second day of testing. I had a bunch to retest because I was going down to 2.0v

[Bigislandguy]

To speed up my testing process. I set the discharge current to 20A. My result was roughly 5.18ah and lasted for 20 minutes till it reached 2v and the alarm 🚨 went off. A few minutes later nominal voltage rises to 3.08v
I’m not sure how accurate my test is, but now I’ll try to discharge it at 2a

[Bigislandguy]

how long did it take you to complete testing for all those batteries.
Is there a faster way or a better load tester? Reason why I’m ask is because I bought over a hundred used cells from (BH ) and I would like to know what I have.

[kgsalvage]

Did you take them down to 2.0v during your capacity test? I see that the discharge cuttoff is 2.0v. I thought most LiFePo4 batteries were 2.5 - 2.6v. Is it safe to go to 2.0v on these?

[joegama]

1.6 amps is equivalent to what c rate discharge?

[reidlanham]

Cool test! Subbed and following. 73, K8JLW