Rapid BAttery Charger

[bigbarrels]

Originally Posted by jbm

How many Amp-Hours is your battery? And how fast do you need it charged? 12V or 6V?

12 volts and 10.5 amp/hr........looking to charge as fast as possible if plugged into a generator

[jbm]

Any 10 amp car charger should work fine. It should charge in under an hour unless it's fully depleted. Just watch the temperature of the battery while it's charging. It shouldn't get more than warm to the touch. If it starts to get real warm, disconnect it.

[GregAndrew]

If I remember correctly, when the voltage is held constant, then amps = watts/volts. So a 5 watt solar charger is only going to give you 5/12 amps per hour of charge. So 12 hours charging time will produce 5 amps. Might need something in the 12 -15 watt range to keep that size battery charged (with the spare battery charging all day).

[jbm]

Originally Posted by GregAndrew

If I remember correctly, when the voltage is held constant, then amps = watts/volts. So a 5 watt solar charger is only going to give you 5/12 amps per hour of charge. So 12 hours charging time will produce 5 amps. Might need something in the 12 -15 watt range to keep that size battery charged (with the spare battery charging all day).

You remember correctly. And that 5W rating is generous. You'll probably only get about 0.3 amps out of it on a sunny day.

You can do the jumper cable thing, but have the vehicle running. And again, monitor that battery, watch for heat or gassing.