A “battery” is made up of “cells”. Each cell is an individual unit that cannot be split into a lower
voltage component.
LFP cells have a nominal voltage of 3.2-3.4V. This is the voltage that the cells drop back to when at
rest. They will stay around 3.2V until about 90% discharged when the voltage will begin to
decrease until fully discharged at 2.5V. It is highly recommended to discharge less than 80% of the
cells total Amp Hour capacity. This will help to maximize the cell life.
LFP cells may be connected in “series” (+ to – to + etc) to obtain a higher nominal voltage. This
creates a “battery”. They may also be connected in “parallel” (+ to +, - to -) to increase the Ah
capacity. Under no circumstances should cells or a battery be short circuited, that is the +
connected directly to the – to create a loop. This will damage the cells and most likely the operator
also.
Under no circumstances should the cell voltage be allowed to fall below 2.5V for a sustained
period. Permanent damage will result. It is possible that this situation may occur if the battery is
allowed to stand for a long time (ie. months). In this situation the BMS will not allow recharge
because a cell is outside the safe range. To try and rectify the problem a small 4.5V 300mAh DC
plug pack type power supply can be applied to individual cells one at a time until the cell voltages
rise above 2.5V and the BMS will allow normal charging to commence. Care must be taken with
the first few charges as the battery may be severely unbalanced.
A visual check of the battery pack during charging should be made every 3 months. Switch off the