18650 Over-sized 3.7v charger?

Built some 18650 6cell batteries, and charge/discharge/charge testing can take... quite a while... using an Opus, at 1a. Even 2a (using only the outside slots), takes a while.

Did some searching, yet can't seem to find a high-capacity 186503.7v single-cell (or multi-P)charger... is there such a thing?

Not sure if I got this, you have put several cells in parallel and want to test all of them together, is that correct?

If you mean just charging, it might be cheapest just to get a beefy bench/lab power supply with current limiting, and you can use a multi cell holder to place multiple cells in parallel to charge. It's not that convenient since you still need the cells to be similar state of charge before putting them in parallel, and a bench power supply has no charge termination which isn't really healthy for the cells.

rev0 said:

If you mean just charging, it might be cheapest just to get a beefy bench/lab power supply with current limiting, and you can use a multi cell holder to place multiple cells in parallel to charge. It's not that convenient since you still need the cells to be similar state of charge before putting them in parallel, and a bench power supply has no charge termination which isn't really healthy for the cells.

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I've heard of "bulk charging" large cells, then using a correct CCCV charger to finish the charge, yet yes, that does involve involvement, and would not be preferable.

DarkRaven said:

Not sure if I got this, you have put several cells in parallel and want to test all of them together, is that correct?

Click to expand...

Yes. 1S7P, 3.7v, spot welded.

Search for "adjustable DC electronic load", or variations of this, and see if one comes up that fits your needs. Or use a charger like one from the iCharger series, the biggest one (4010 Duo) can dissipate 130W per channel or 200W together internally. It's not cheap though.

Also be aware that this method isn't a good idea if you have used different cells. Obviously you won't get separate results for each cell. You want separate results though if you are using reclaimed cells.