I have a DC power supply from either a WIFI router or printer (not sure) rated for 13.5V @ 1.2A output.
This is a replacement charger for an electric ride on car as it was originally 6V and I've upgraded to a 12Vbattery and system.
Without load, the charger puts out about 14.8V and roughly 14.6V when plugged into the original DC plug to charge the SLA battery.
I'd like to utilise this charger but require a voltage reduction to charge the battery. I'd also prefer 13.5V charging voltage so I don't need to watch the battery temperature all the time, but am concerned about heat dissipation for that kind of voltage drop.
- What method is best to reduce the voltage, and/or the most cost effective way? I'd like to stay away from a buck converter if possible. I've also looked into using resistors or a potentiometer as a voltage divider.
- What specifically will a resistor affect my charging current, and how much will it drop?
- In terms of heat, is it even viable to use a resistor to drop to 13.5V?
Further info can be provided if needed.