Hi,
I have a generator that has a rechargeable battery. The output specs on the AC adapter to charge the battery are 12V DC 1000mA. I cannot find the AC adapter. I do have an adapter that has output specs of 12V DC 0.75A.
Could I use this adapter to charge the battery or will the reduced output of 0.25A damage the battery and charging system?
Thanks

 

It will work but might take longer to charge because it's lower current, it won't damage the battery.

 

What You really need is called a "Battery-Maintainer".

An unregulated Power-Supply may damage your Battery.
.
.
.

 

Could I use this adapter to charge the battery or will the reduced output of 0.25A damage the battery and charging system?

If the battery is SLA, a regular 12V adapter won't work. Even if the voltage was high enough to charge the battery (around 13.8V), it won't charge the battery correctly. A battery maintainer would be more appropriate. Most will also try to recondition dead batteries.

I've recovered several 12V SLA batteries using maintainers, and several car batteries. None would hold a charge. They do now, but they're still weak. It took months to get some of them to charge.