Thanks for the reply!The shorter, the better. There are clear indications/research that keeping a cell at 3.65V isn't a good thing.
Personally, I would say hours.Are we talking hours, days, a week? A month?
Very interesting. So are you suggesting not top balancing? They are brand new grade A EVE cells. All at 3.28v. Can’t I just set them up in my 8S2P configuration, hook up the bms and let them balance?The instant there is no room in the anode for further intercalation of lithium ions, and charging is still occurring- metallic lithium will begin to form.
The lower the current, the more localised the plating (ie: dendrite formation)
The question you should be asking yourself is why take a LiFePO4 cell close to saturation?
My advice is to stay as far away from the top of the upper voltage knee as you can.
Thanks for the response. I’m not trying to get out of top balancing. I’ve got everything set up and ready to go. I plan to do 8 cells at a time with bench power. So do I need to manually discharge them afterwards, or will they come off to a safe idle voltage?The original question..
They are not going to sit at 365 after top balancing. As soon as you remove the charger, they will come off of 365.
However, I didn't see any responses that said do not top balance. You should top balance.
So do I need to manually discharge them afterwards, or will they come off to a safe idle voltage?
I do believe you meant "... you stop charging ...".The moment you start charging they start settling.
Yes.. thank you.I do believe you meant "... you stop charging ...".
So how long is ok at their settling voltage after top balancing.
I use your second option with my 48v 100Ah battery. Whilst assembled I charge each batch of 4 cells with a Victron 12vIdeally, you would top balance them one cell at a time (each cell to 3.6V or even 3.55V or so, doesn't have to be 3.65V). The main reason for doing this is so that a full cell isn't kept at voltage waiting for other cells to catch up and you can overcharge a cell this way. Another way to do it is assemble them in a battery with BMS, charge the battery until you reach high voltage disconnect on one of the cells, and then top up the rest individually.
You can also just throw them together and have the BMS balance them over time. This works, but you might have to be patient before you can use the full battery capacity, and you need a BMS with a decent balance current preferably
Very interesting. So are you suggesting not top balancing? They are brand new grade A EVE cells. All at 3.28v. Can’t I just set them up in my 8S2P configuration, hook up the bms and let them balance?