Does anyone have a recommendation for charging 3s7p li-ion packs? I've built some power banks with 3 of these packs in parallel so something that would float at 12.6v and push maybe 3amps?

I got some laptop battery pack I want to test them with opus C3100 V2 what is the ideal way to test their capacity without wasting much time as i understand charge to 4.2 V then dicharge to low cut off Voltageyou got the real capacity this is automated via opus chatger with mode charge < test Does this all what I need ?

Looking for a good pair of snips for cutting nickel strips, any recommendations?

Resurrecting my Ryobi battery packs is the whole reason I started doing this stuff, and then I got distracted by buildling packs for go karts and making my own rotary tools out of power window motors and stuff...I've circled back now and have stuffed new cell into three defunct packs at this point, and in all three cases, the BMS seems to either be bad, or be programmed to not cooperate. Thinking I could just order some less expensive 5S 30A BMS from ebay or whatever ( Maybe like this ) , with footprint small enough to fit between the tower and the front of the pack, chop the front of the old one off with a cutoff wheel and run wire leads back to the appropriate tabs. Has anyone done something like this successfully?

Holding onto about 1000 or so samsung INR2170 50E cells and looking to be rid of them. What is the best way to sell them?

This speaker is designed to run off 1 cell on the left side, so I spot welded and soldered in 2 more in parallel (used yellow since didn’t have red wire). There’s a Thermistor on the original battery but I skipped it for the new ones. It looks like the BMS and charging is handled by the main circuit board so I think this might be fine?

I didn't see any rules against making posts like these, so mods please take down if I'm mistaken.

I have a set of new in box BMS equipment from Batrium that I'm selling in the US. I was going to return it to Batrium, but the shipping from the US to their office in Australia is ~$200 so I figured I'd resell more locally.

Selling as a bundle:
1x WatchMon Core
1x Cellmate K9

1x ShuntMon 500Amp
1x Expansion board

This bundle of gear is a standard package that you'd need to set up a diy battery. The equipment is more expensive than some other options on the market but also higher quality. DM if you're interested. Price point of $600, free shipping in US

Hello guys, I know this question is probably asked a lot but for safety reasons I want to ask you guys to look over my shoulder so to say.
I have this battery pack to power my project: https://www.amazon.de/dp/B0DPBNQ2J4?ref=ppx_yo2ov_dt_b_fed_asin_title
these are H18650CQ BAK A02
in 2S2P configuratiuon
with charging data per Cell:
Charging Cut-off Voltage: 4.20V
Max Charge Current: 2.6A

so the calculation for my charger should be:
Charging Voltage: 8.4V
Charging Current: 5.1A

Are these numbers correct? I am a bit nervous working with them so I appreciate if someone could walk me through my errors.
Thanks guys

Wanted to fire up my old tablet with no 5V power supply handy, so I grabbed a pair of linked 18650 batteries that were laying in a drawer. Fired up with 12% battery! My custom battery holder works great. 😁🤦‍♂️

I am using a BW-6022-5S BMS and I want to exclude overcurrent, overdisharge and overcharge protections while maintaining cell balancing. The attached picture shows my questions and possible solutions I need to verify with your help.

I assumed pure nickel is easier but I found a guy arguing the opposite somewere here on reddit so I thought I'd take a poll

View Poll

https://preview.redd.it/f4g7dvhiwmfe1.jpg?width=3472&format=pjpg&auto=webp&s=b620356ce2c224ec25c9e1e157bba7756824c527

I just received my SUNKKO AD709AD+which came with Welding Pen S70BN. In first inspection I've noticed the leads are in contact inside the handle. Is this a problem? Surely the design wouldn't allow this much risk of them touching? What are my options here?

• Assume it's okay as it passed QC and use as normal.
• Separate with some fish paper to insulate, then use as normal.
• Send it back.

Edit, on closer inspection the leads have fused together, so this indicates use. They do a test weld before shipping but could this be a used or poorly refurbished unit? This is really a WTF situation that there is no insulation in there. The braid is loose in there to allow for the pen to retract up the shaft.

https://preview.redd.it/a3bpq2dwtmfe1.jpg?width=2439&format=pjpg&auto=webp&s=c4d9143b76f80ba050ebcf6a851d557ec4d09a52

Hi,
I am repairing a battery pack, the cells do not have a part number but they look exactly like 18650 cells, they are apparently protected due to the length, have a flat top, not button and the shrink wrap around the pack says "LY-ON rechargeable sulphide."
Any idea where to get these cells? I found lyten, but no info on how to purchase and they do not answer emails.
Thanks!

Just bought 10 of them, I’m using for electric chainsaw, lets see the results..

Hi, want to replace the batteries in my portable 14.7V vacuum cleaner as it won't charge anymore. Unfortunately the batteries do not have any markings regarding maH and discharge rate, so I don't know what batteries I need to purchase.

Does anyone know what the maH and discharge rate of this battery?

I think 2000 mAh at a 2.0 volt and you?

Im thinking about buying a new tester/charger for my 18650 cells, when i came across this on aliexpress: https://a.aliexpress.com/_EvKoVQu

I dont know much about this and thats why im asking you guys. Thanks

Hello, please let me know if this is the wrong place for a question like this.

I'm currently (unsuccessfully) using the Kweld to weld .3mm nickle plated copper strips onto prismatic cells and trying to troubleshoot as to why the welds are failing. Any advice is welcome.

I'm using a car battery as my power source. It's rated for 550 Cold Cranking Amps (which i imagine is higher when not working in a cold environment like myself), and has a voltage of 12.6V. When I attempt the weld, it fails with the "Timeout" error code. According to the Kweld, this means either the power supply cannot deliver sufficient current, my electrode contacts are insufficient, or the circuit resistance is too high.

However, according to the post-weld readout, the average current delivery is ~1600 amps with a circuit resistance of 0.14mR (For a total circuit resistance of ~2.55mR). At a voltage of 12.6V, I have no idea why these values result in a timeout error (meaning the target 100J of energy couldn't be delivered within 200 milliseconds, causing a premature disconnect).

To reach 100J in under 200 milliseconds, I calculate that I need at a minimum 500Watts of power. 12.6V at 1600 amps far exceeds this. I find all these values suspect however, I would expect Current = 12.6V/.00255, which would trigger the over current protection. That isn't happening though...

I suppose that leaves the failure case of my electrode contacts being insufficient, but idk about that one. I'm pressing down pretty hard. I'm not sure how else to remedy that

Other details that may be relevant, though I'm unsure of how:

Resistance of the circuit calculated during calibration: 2.41 mR
6AWG
.9 meter total cable length

It took out a smart car parked next to it. I got this picture of the BMS corpse as I was walking past. I don't have any other pictures.

Got these 18650s second hand and don’t need to use them right now so I want to store them away for a while, how can I safely do this if the wraps are damaged? Can I wrap the damaged areas with electrical tape and slap them into the same box? Thanks

I need to re wrap some high capacity 18650 protected cells and they are quite long, normal wrapping does not seem to do the trick so where if any, do they sell longer versions of the wrap? the 72.5mm wrap certainly isnt cutting it.