What is the ideal charging voltage?

[okrobie]

I have recently refurbished a TaoTao E-Scooter Model number ATE-501 with the help of friends on this board. It has 4-12 Volt 18/20 Amp Hour SLA batteries. I recently acquired a variable voltage power supply which can be adjusted to a maximum voltage of 53.5 VDC I tested it on the batteries last night at 53.5V and it started charging at 2.5 Amps and dropped, as the battery charged, to zero when they reached 53.5 Volts.

My question is, should I be charging this high or higher? Or should I adjust it lower? Thanks

 

[john61ct]

Each battery is different, and has its mfg specs for Absorb voltage and how long CV stage is held - stopping at a certain trailing current defines 100% Full - before dropping to Float.

Getting there, and storing there, is important for longevity.

Above 56V for sure, could be 60V.

But holding endAmps past say .005C, or no change for a full hour,

risks overcharging, i.e. losing too much electrolyte which being sealed cannot be put back.

Get the spec sheet from the maker, or contact their tech support.

 

[john61ct]

Quality true deep cycling AGM, for longevity actually prefers a much higher charge rate, 0.2 minimum, 0.5C is not too high.

GEL chemistry is much lower, both voltages and C-rates compared to AGM.