While waiting for my 24VDC motor to arrive decided to look into charging batteries and was surpri...

[G+_Rud Dog]

While waiting for my 24VDC motor to arrive decided to look into charging batteries and was surprised to see one video where a standard power supply was connected to a 12VDC Lead acid battery for charging purposes. Could not tell from the video so will ask here. What is the polarity of the power supply connection to the battery?

[G+_Ben Reese]

What are you calling a "standard power supply"? For charging purposes, it would be positive to positive / negative to negative. A charger will most likely output a higher voltage than the battery it's charging (a car's alternator typically runs around 14v to charge the 12v battery).

[G+_Rud Dog]

Ben Reese looked like a tech-shop adjustable power supply with current and digital readout. Guess I was wondering if you keep a close eye on the charging time it would be safe to charge a battery this way? Of course it would need to be capable at least 5 amps for the start of the charge, correct?

[G+_Daniel Armstrong]

For lead-acid you can float charge, just apply about 2.2-2.3 volts per cell limited to C/10 amps and set-it-and-forget-it as Ronco would say. So a 100 amp-hour 12v lead acid would be current limited to no more than 10 amps and a voltage setting of 13.2 volts. Normal charging would be limited to 2.35 VPC for gel, 2.4 VPC for flooded, and just under 2.5 VPC for AGM. All voltages at normal room temp, lead-acid has a negative temperature coefficient of charging, as the temperature goes up the voltage must be lowered.

 

DO NOT overvolt gel batteries, the gas formed will permanently force the gelled electrolyte out from between the plates.

[G+_Rud Dog]

Daniel Armstrong Thank you for your time and info. Found an old charger my dad used to use it has 6 and 12VDC selector switch along with a switch for low maintenance and damn forget what the other setting was for but hoping this will do for my charging needs.