bournevexed said:
Will take a while with 7 at a time on 4 chargers(2 liitokalas, 1 opus bt3100 & 1 imaxb6v2) but I'll get there lol
I am ordering that spotwelder & lipo battery today with help from my other half!
Erm, not exactly
bournevexed. I have six Opus's, four still working 100%, and I love them to bits. BUT they aren't used as chargers... welcome to the forum!
IMHO, The Opus BT3100 is NOT suitable as a charger -- ESPECIALLY for old/recycled cells. You may wish to thrash your new cells in them but I wouldn't recommend that either. I have TWO basic reasons for this assertion:
1/ Basically the
method of charging it uses is very brutal pulses which can be way out of spec for the cells.
To quote from the battery charger testing master (!), talking about v2.1 ...
"The first version of this charger had some nasty 9A current spikes from the power supply, this made the charger show wrong mAh values when charging. In this version the spikes are reduced to 6A and the charge current is stable, this means the charger can measure correctly."
https://lygte-info.dk/review/Review Charger Opus BT-C3100 V2.1 UK.html
2/ In any case, if you are like me, the
capacity TESTING is the bottleneck.
So I use 'big 4s20p trays on a CC/CV buck converter to 'slow cook' my precharging batts (anything <3v) to get them up to 3.8V ish then top them off with an iSDT balance charger. Takes 5-10 days. but then I have 160 cells to test (I generally process my cells in pairs). And for day to day use I use 6s4p yoke's on balance chargers to keep things charging for the Opus capacity testers.
I mention this all now, as you are ready to blast away at your task, and thought it prudent to tweak your method so you dont end up changing the way you grade / measure cells half way through your mission. Hope That Helps.
PS you may want to pop open your Opus and future ones if you get more to check that J1 is set the same on all of them, as this setting fundamentally changes the capacity values it gives.