Hi, I recently aquired 4 second hand 90Ah Victon Lifepo4 Batteries, that are around six years old (not smart model).
I received them at very low voltages (the lowest was at ~9V), but was surprised to see that they would all take a charge.
After they were individually charged, i then (again individually) did a capacity test on each of them with a 4.5A load, and found that they still had between 75 and 80 Ah of their original 90Ah.
I then fully charged them, and balanced them at 14.2V (again individually), until they each were only drawing 120-150mA. This took around 8 hours for each battery.
Now i have set them up to test them as a bank, they are connected in 2s2p configuration for 24V.
The bank has been charged now from a generator through a Multiplus 24/3000/16.
However, Once they reached float i decided to put the multimeter on each battery, and found that one battery on each series string is considerably higher than the other, at float one battery was at 14.5, while its friend in series was only at 13.6. The other series string was in a similar but slightly less drastic situation.
Does this suggest that the batteries are unsuitable for use together?
Or should i configure them differently in an attempt to balance them (both high units in series and both low units in series)?
Thanks for reading =)
edit: I just looked at them again - the generator is off and they are running the lights in my house at the moment which equals 40w, and now if i stick the meter on them they are back in balance, so it seems at the moment that they are only out of balance at the top of their charge cycle...... does this provide any clues?
