On Board Charger

[Luremaker358]

I need to know how to check to see if your onboard cahrger is working. I a battery to go bad and when I put another battery in, it seems like the charger isn't working. I plugged it in an all three lights stay red and don't turn green, like it use to.

[Barnacle Bill]

Unplug the charger
Disconnect all leads and situate them so they can't ground out
Plug the charger in and measure the voltage at each set of leads.
They should read aprox 13.3 VDC if the charger is good. If less than 13VDC you have a problem with the cahrger.

If no voltage check the fuse.

[Luremaker358]

I had a guy to check the batteries and he said they were alright. I will disconnect and check the voltage, Thanks

[CatFan]

Don't jump to conclusions if you don't get any voltage. Some chargers won't put out anything if they don't sense a battery drawing current. You should see 13.3V with the charger on and connected to a fully charged battery. 14V-14.8V with the charger on and connected to a partially discharged battery. A completely dead battery will not show any voltage as OB chargers can't charge a battery that is completely dead.

[Barnacle Bill]

Those directions come from a Pro Mariner manual,

[Luremaker358]

Thanks guys I disconnect the batteries and check voltage. I didn't get any reading. I hook up the batteries and recheck. The meter read 13.3 volts on each batetery with the charger on. The batteries check 12.4 volts with the batteries disconnected.

Thanks, luremaker358

[CatFan]

Thanks guys I disconnect the batteries and check voltage. I didn't get any reading. I hook up the batteries and recheck. The meter read 13.3 volts on each batetery with the charger on. The batteries check 12.4 volts with the batteries disconnected.

Thanks, luremaker358

If the charger is only putting out 13.3V, it is reading the batteries as charged or very close to it. 12.4V is less than a 75% charge though. They should read 12.64V or higher depending on the brand. So what you have is a charger that thinks the batteries are almost charged when they aren't. With batteries that discharged, you should see the charger putting out 14-14.5V.

The only suggestion I have is to thoroughly clean all of the connections at the batteries with a wire brush. Make sure the connections are tight when your reconnect (use a wrench), and run the charger for 24 hours and recheck everything.

[Barnacle Bill]

Luremaker, what brand charger are you using? You got my curosity up.

[Wannabe...]

If it turns out to be a poor connection and you're using wing nuts. Take the wing nuts and throw them as far as you can then replace them with stainless nylocks and a stainless washer. Finish it off with some battery sealer from NAPA and make sure you have a tool onboard in case you have to remove it on the water.

This post reminds me that I need to got out and record the voltage on my working charger and good batteries. That way, if I ever have a problem, I can compare the voltage and see what's different.

Wannabe...