what an excellent question! ... glazed eyeball alert... to answer requires an understanding of how a LiFePO4 battery functions. how it charges back up and what happens as battery approaches fully charged state. first lets address how LiFePO4 cell discharges it's power. meaning it's discharge curve is not completely flat like a lipo or lithium cobalt cells. LiFePO4 drops 1 volt for the first 10% of discharge, then only drops about 1/2 volt for remaining 90% of power. Shorai's chart apply to all LiFePO4, cylindrical or prismatic pouch .. notice 14.6v or fully charged to 13.3v covers 10% of total available power. discharge curve is almost flat for remaining useable power. 13.3v to 12.86v is where useable power range occurs, less than 1/2 volt range. more power is available down to 12.73v for another 10%. but it's best not to drop below 12.85v for max battery life. now let's cover what happens during last part of charge cycle. which happens to be identical to discharge cycle but in reverse. when recharging a LiFePO4 battery first goes into bulk mode. when battery will basically accept all the amps you can throw at it. most chargers get no where near limits. as battery gets closer to full, LiFePO4 naturally slows down rate of current absorption. when current absorption slows down to milliamps or almost zero current flow at 14.6v. an intelligent battery charger will reduce voltage down to 13.6 range or float mode. if one removes battery charger before LiFePO4 is allowed time to fully absorb charge and current is still flowing at 14.6v. then battery's voltage will drop back down to voltage matching actual stage of charge shown on Shorai chart above. for instance if your 8cell LiFePO4 measures 13.1v with a known to be correct meter. it's at 40% state of charge. this is the principal that Optimate Lithium LiFePO4 chargers uses to balance cells without separate balance ports. Optimate lithium stops charge before LiFePO4 cells has reached full charge. then allows voltage to drop back down, then starts charge cycle back up again. each cell has different internal resistance that control rate of charge. by stopping charge cycle, then restarting ... this allows cells with less charge state a chance to catch up to cells with higher charge state. Optimate Lithium measure internal resistance to tell when LiFePO4 battery has reached optimal charge. which will different for different type LiFePO4 batteries. whew... got to stop typing .... too much info all at once puts most folks (including me) to sleep....zzzzz will cover your 8 cells LiFePO4 a bit later ..