Replacing original onboard battery charger

[Hat43c1981]

Hello All,

I believe my onboard (original) battery charger is on it's last leg. I am amazed the charger has last for 39 years! Impressed! It does not appear to be charging the port bank of batteries and it is short cycling while its powered up. Comes on for about 8-10 seconds, shuts off for about 8-10 seconds and then turns back on. I will be replacing it with a new charger over the winter. our 43 convertible has a 12v system and I am trying to figure out which charger to buy that will be the most "plug and play" option. Wondering how many amp charger I should purchase. Our Hatt has two battery banks. Each bank has (2) 1400 CCA 8D lead acid batteries. We spend most of the time docked and on shore power and if we are out on the lake for extended periods of time I use the genny for electrical power. So we don't really use the batteries for much with the exception of starting the Detroits and powering the vacuflush waste system, oil change pump once a year and a few DC lights. Thanks in advance for any advice or direction you can provide.

Stay safe and healthy out there!

[MadHatter53]

There is plenty of options in the 12V world, I think 30amps is good but I can’t recommend a manufacturer.

[HP12Sea]

I'd rec Newmar. https://dcpoweronboard.com/battery-chargers/

Reach out to them with the same question. See what they come back with.

Good luck.

Sales
salesDPO@newmarpower.com
Tech Service
techservice@newmarpower.com

[madhatter1]

Are the engines 12v as well? Hatteras has a 12/24 system where there is one dual bank 12v charger for two 12v taps and then 2 single bank chargers for the second battery in each group. That is because the second battery negative is connected to the first battery positive. Therefore the second battery charger “negative” is not/cannot be grounded.

[Hat43c1981]

I believe the Detroit 6V92's are 12v. I will admit, I am not completely familiar with the battery set up. We just purchased the boat this year and I am attempting to learn and gather as much info as I possibly can. I tested the batteries and the port bank (2 8D batteries) were reading only a 30% charge on both. So I am left to believe the charger isn't doing it's job. Plus with the charger coming off and on like it is. Thanks for all of the input so far!

[madhatter1]

Take the covers off the battery boxes and post a picture. Very easy to tell you what you have.

[Hat43c1981]

I will take a few pictures when I am on the boat later this week and post them to this thread. Thanks!

[rsmith]

It’s a good chance the batteries are bad not the charger

[Hat43c1981]

It’s a good chance the batteries are bad not the charger

I tested the 4 batteries. 3 of the 4 are good. One needs replaced.

[SKYCHENEY]

I tested the 4 batteries. 3 of the 4 are good. One needs replaced.

One bad battery will make the charger act funky. You need good batteries first.