Do I need the charging controller for LiTiO?

I'm just now configuring my PV system. I choose the Toshiba SCiB 20ah cell for my battery array. For protecting the cells of undercharging or overcharging I will use BMS (Battery Management System) for this type of batteries.
So, I don't understand why I should to get the charging controller for solar panels if the voltage of the solar array and the voltage of the battery array are same. I don't need to transform the voltage of charging and the current of charging controls BMS. I think that I don't need the charging controller for solar panels. I'm right?
If you can urge me to use the charging controller for solar panels, please, help me to choose cheap and effective controller for solar panels with LiTiO batteries.


  • BB.BB. Super Moderators, Administrators Posts: 32,998 admin
    BMS are not a substitute for a charge controller.

    BMS systems are intended (usually) for balancing cells (every cell has the same voltage by moving a "small amount" of extra charging" current around a "full cell" so that other "lower cells" can fully charge), and (some BMS) prevent a cell from overcharging or over discharging (either shut off cell itself, or send a signal to a master relay/control to disconnect the entire string/bank).

    For example, with lead acid batteries, the cells are "rugged" or "forgiving" enough to that they can be over charged (equalizing charging), and they do not go "dangerous" if over charged/over discharged (you may ruin the bank, but they will not catch fire or explode or be ruined if you go a few tenths of a volt over/under the cell specs.

    BMS systems are either relatively "small" (a few amps of per cell balancing current) when compared to overall charging current, and/or safety trips (like a circuit breaker) that shut down the entire bank if something "goes wrong".

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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