On Board Charger issue?

I’ve got a two bank 12amp ProMariner.

And, I’ve got two batteries that are going dead routinely.

I also have a load tester, so will test both batteries this afternoon.

I’m believing currently that the batteries are good as they’ve taken dedicated charges all summer.

I had installed an isolation unit between the two batteries so that the accessories could not drain the starting battery.

Then I thought I put a charge with the ProMariner on both batteries, 12-16 hours.

Both dead. While we were jumping the starting battery, the helper touched the handles together for a short while, sparking pretty heavily ~1/4 second. We did get the engine started and ran it for 30 minutes, shut it down and started it 2 hours later and ran it for another 30 minutes (BayPointe up to the dam at 2000 rpm)

So, assuming the load test shows good batteries, what do i do??

I’ve got voltmeters here, so i could go testing for 14.3.

What should i be testing??

I’m thinking:

1. the alternator,

2. AND the ProMariner

BUT, after that, i’m stumpted…

If I remember correctly, there is an inline fuse on the output of the ProMariner which could be blown, but i’m not understanding why it would go from such a brief cross circuit, except to protect against reverse voltage…

Comments??

Check the output of the charger with your voltmeter as a first step.

and it should be ~14.3 or so, correct??

I would definitely have batteries load tested. Cold weather seems to kill a battery that was on the end of its useful life.

Stu, when my proMariner started to give me problems, i called pro mariner and shipped out my old unit and they sent me a New unit, and i didnt even have my receipt. If the charger is the problem call Jim Mitchell at 1-603-766-7602 hes is the manager, great guy. Hope you get the issue under control. Jim :

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and it should be ~14.3 or so, correct??

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sounds about right, it that checks out, even if the the batteries pass the load test, I’m still sticking with bad batteries no matter the load test results, from my experience unless they test bad, a “good” test result means nothing, had plenty that’s tested fine and not until I replaced them was the problem fixed.

The battery that was on the dedicated charger tested low, but OK. The other battery didn’t register at all. I put it on a charger and will look into it more tomorrow.

I did NOT have a voltmeter (except the one on the load tester) so it’s off to NAPA, Menards, FF (goll if i go in there and rapalas are on sale…) Any advice? digital vs needle, etc

checking the voltage of a charged battery after it has stabilized the voltage should be 12.5 – 12.7. While your outboard is running you should see at least 14.3 volts but no more than 14.7. ( that is what your regulater is for).Checking the voltage while the batteries are being charged by the onboard charger should be at least 13.5 volts or so….

I might be wrong, but sounds like a couple bad batteries. Sometimes just time to replace and call good. On a side note, soon as possible post fishing, the charger is plugged in-this policy has gotten me maximum life out of ’em.

could be the case.

i’m headed out to run a load test on #2 after a charging attempt.

if it’s bad again = new battery and may as well do both at the same time so i KNOW the aging on them.

this is irritating as both of these batteries were new 1 year ago and don’t have even 20 starts on them…

so a trip to NAPA and FF is on the books today.

wish it weren’t 15F…