Building an old. worksman trike and want to use a 12v sla to power the lights. Got two 12-12ah batteries but lost the charger. I found a different one but similar that is 12v 3ah charge rate. Will that work?
If the charger is for a 12V battery then it should be fine. The charging voltage should be somewhere between 12.9 and 14.4V and not 12V. You can test this by using a multimeter in the charging port leads. I mean it has to be a battery charger for a 12V battery... Also, take a look at the charger to make sure it has overcharge protection if not you need to periodically check the voltage to make sure you do not overcharge the battery. If you can take a picture of the back of the charger with all the information this will be helpful to verify.