Initial charge voltage levels
Question: I wish to equip my workshop with the proper tools. Can you offer me following chargers: one model with cut off voltage at 3.65V, one model with cut off voltage at 3.80V and one model with cut off voltage at 4.00V?
Answer: There is no need to have so many different chargers. The typical chargers that are sold by GWL charge to 3.65V (for single cell). Please see some additional comments.
In the past it used to be recommended to charge to 4.2V or to 4.0V or to 3.8V. However over the time, as the technology of the LFP cells has become more stable, it seems that the there is no need to make the initial charging to such high voltage levels. It is sufficient to charge to 3.65V. (Some customers even reduce this voltage to 3.55V or even less. The lower the final voltage, the longer the life span). Generally it is recommended to operate the LiFePO4 cells between 3.50V and 3.0V
If you have a special need to make charging to a fixed voltage, we recommend using the laboratory power supply.
We always recommend making the initial charge and balancing the cells to the same voltage (e.g. 3.65V). This initial charge should be done by individual charging of the cells, by identical charger or method.
However in the regular use, it seems practical to avoid charging to this full voltage. Perhaps you decide to charge only to 3.55V per cell. For 16 cells you will be charging to 56.8V per pack. This way you will operate the pack at optimal charge level and avoid the over charge.
If you have additional questions, be sure to contact us for more support.