I have a 40hp evinrude model number 40604R. It has a 5amp charging system that is functioning. My question is, can I charge 2 batteries at the same time?
The answer is yes. BUT, you have to remember that it will not charge either battery at 5 amps. Simply because the current will now get split to two batteries instead of one. And if one battery has a less voltage then the other, it will push more current to the lowest voltage level battery because it will have the lower resistance reading. Some folks use a battery separator and try to keep them separated while charging.
OK thanks. What I was doing is I installed battery charging clips on the ends of the charging wires. And just moved them from one battery to the other.
How are your batteries wired for use? If they are hard-wire paralleled together, moving the charging wires between batteries is pointless. If you're using one battery (or both) for a trolling motor, a 5 amp generator won't be adequate. - Grandad
One battery for starting, and another separate for minn kota and sonar, lights etc. I dont expect the 5amp charging system to keep them fully charged. I know I need to charge them after each outing.
If your going to be charging the trolling battery after each outing just keep the starting battery hooked up,to keep it fresh.
As far as the trolling battery goes unless you make some amazing long runs getting to your fishing holes charging would be like spitting in the ocean.
OK thanks, I was not sure if both batteries would charge at the same rate. I know what you mean by spitting in the ocean. One time I left the key on. And I could not run the motor long enough to start it.
The stator is designed to maintain a battery not to charge a discharged battery. You can burn up all sorts of ignition components by overstressing the system by doing this on a regular basis. CDI wrote a warning about this in the troubleshooting manual.