Whoopsie! A 3.75v Xuba 280aH Cell

[heirloom hamlet]

The simple answer is if all of your cells are charging and dischargin at the SAME rate -- amd you do not have a runaway cell (either one that charges way ahead of the others OR dies quicker than the others) then YES you are balanced ... the first time you hook the batteries to a real SCC then everything will flatten out and you will be fine ...

The #1 killer of LiFePO4 is HEAT ...

#2 is ppl trying to tune their batteries to get it to 99.9999 and messing up and not paying attention and pumping them up too much ... LiFePO4 does NOT like to be OVERCHARGED at all ... at maximum voltage strange things start happening to the little bouncy balls inside of the battery ...

My advice to you is to drink heavily ... wait .. wrong forum ... but try to get all the batteries as a level as you can -- and then see if they hold there for 24 hours .. if so -- then you are TOP balanced enough .... you are actually scaring me with going above the volts you should .. i think you have been lucky so far ... but i wouldnt do it again ....

Okay, got it. Scared straight. So setting lower than Will's 3.65, you think, like 3.55?

When you say sit for 24hrs...as individual cells, or sit in parallel?

 

[ghostwriter66]

Okay, got it. Scared straight. So setting lower than Will's 3.65, you think, like 3.55?

When you say sit for 24hrs...as individual cells, or sit in parallel?

So we do our batteries a little different but we have a massive warehouse and what i would call a NON-typical setup ... SO when I get them in -- I drain each individual battery HARD to virtually zero using some mega heat sinks -- then charge each of them HARD to 100% -- (I charge and discharge them HARD so as not to waste time) ... when they are all at the same max voltage - i pull them off the bench and let them all sit ... next morning I take a DVM reading and if they are within 0.2 of each other then I strap them together to make whatever battery size I need .... and then put them on the SCC ... and literally NEVER check them again for about a year .... it is VERY hard to get LiFePO4 batteries out of whack unless something like lightening strike - over charging - or charging below 32F has been done ...

 

[ghostwriter66]

Okay, got it. Scared straight. So setting lower than Will's 3.65, you think, like 3.55?

When you say sit for 24hrs...as individual cells, or sit in parallel?

3.65 is fine ... 3.55 is at the lowest I would go ... 3.7 is the highest ... BUT you need to keep an eye on it unless you got yourself a damn good charger with TIGHT tolerances ...

 

[Craig]

What @Ghostwriter said. 3.65 is totally fine this will never overcharge them. even 3.8 is ok but you must monitor them so that they do not exceed 3.65v. I hook mine up to a meter then have my computer shut off charging when the cell hits 3.65 volts at the terminals. this way I can set charger to greater than 3.65 and walk away knowing the computer will stop charging. Waiting to get cells to 3.65 volts while charging at 3.65 volts takes forever. I have no problem with you using a higher voltage just make sure you monitor.

 

[Ampster]

@ecualibrium
Hopefully your pack assembly went okay and it is performing well?

 

[tictag]

At that moment I wanted a Delorean with a Flux Capacitor to go back in time a few minutes.

I would urge caution here, there are a lot of fake flux capacitors out there on the market right now, especially on aliexpress.com and, to a lessor degree, on alibaba.com because of minimum unit purchasing levels. Just be careful and read the reviews. You don't want a bad one and end up back in the 17 or 18 hundreds; no antibiotics, no minimum wage ... witch burning, ffs! Good luck with your project.

 

[heirloom hamlet]

I would urge caution here, there are a lot of fake flux capacitors out there on the market right now, especially on aliexpress.com and, to a lessor degree, on alibaba.com because of minimum unit purchasing levels. Just be careful and read the reviews. You don't want a bad one and end up back in the 17 or 18 hundreds; no antibiotics, no minimum wage ... witch burning, ffs! Good luck with your project.

Hah! Idk, depends on who has the worse plague and riots.