Guys,

I’ve been starting to get the boat ready for the start of the season, including a couple projects I’ve mentioned, and happened to notice one of the batteries has not been charging. I’ve got one of these:

Battery charger/tender

And it has been working fine for a couple years now. But this season it’s not acting right. When I checked, the port battery was showing yellow/faulty on the charger, while the starboard charger was showing solid green/charged. Port battery checks ~11.3v while the starboard battery checks 13.5, both checked while not charging. Assuming the port battery was dead/junk, but wanting to make sure, I swapped the connections. Now both batteries show yellow., even after switching the leads back. I checked the port battery while on charge, and it made little difference, maybe 11.4-11.5v.

Port battery is at most two years old. Starboard battery was new last year. Boat’s been in my shop all winter, and has not seen less than 60 degrees or so.

Thoughts?

Thanks. Brad.

11.3 on a "charged" battery is ng. Battery is junk, if your charger is working property.

UnderPsi,

That’s my dilemma. I’m not sure the charger is working properly. I was hoping someone might have some insight before I start needlessly burning cash.

Thanks. Brad.

Put a different charger on it and see if it charges it up ?? That would be the first thing I would do. Somebody you know must have a charger you can borrow. Are you charging them on the bench or in the boat ? I would take them out and charge them separately on the bench.

My onboard charger will not charge the battery if it goes below a certain voltage which is pretty much almost dead at that point. Try connecting a regular charger to it for a few hours and then turn the tender back after removing the charger. This has always worked for me with my shore power onboard chargers.

Reading the reviews on that charger does not give me a warm fuzzy feeling. Use a known good charger or buy a battery load tester.

Ryan,

It was all but an impulse buy from Walmart. Maybe it’s served its purpose for the investment.

Recommendations?

Thanks. Brad.

Bill, Bencini,

I didn’t pull the battery, but it is isolated. I put a standard trickle charger on it. I’ll check on it Monday morning.

Thanks. Brad.

Each cell is 2.2V.

13.5 - 11.3= 2.2. Think you have lost a cell. Hopefully you have some warranty left on it.

Brad,

Assuming lead acid batts? Sometimes they need a bigger hit than a 2A trickle charge to wake them up.

2yrs is a very short time, and both being faulty is unlikely.

The new switching style chargers of course won't start charging unless they have a reasonable voltage to sense at batt. I always keep an older 12v transformer charger around to feed the 12v voltage to get the 'smart' charger going.

You could also get them charged up and tested before you throw them back in for the season.
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