Carver Owners Forum

My house batteries are 5 years old and I will be replacing next season. There are no issues, but feel for trouble free continuity they should be replaced before they fail. As of now I am using Trojan T105’s, hooked in series to make a 12V. I have never run out of battery power yet. Overnight with TV, fridge, toilet and fans, etc We go to bed at 95% and never see less. than 75% in the AM. Of late, the solar has brought them back to the 90 +/- percent by 11 AM. I have limited space in teh battery area, as I would like a house bank of 4, each set hooked in series then a parallel connection to double the AH.

What is the opinion here for replacement. I am leaning towards AGM for the maintenance free water check. I see Trojan makes a 6V AGM, and a gel. Warranty on Interstate is 36 months full replacement. I have two 12V AGM in series to make a 24V system for my sideshifter thruster, so far they work great!

I was looking at putting them under the aft bed, but with teh AC in there it may not be a good idea with the chance of ignition when it comes on.

Hope to see lots of suggestions and scenarios.

Thanks as always!

Sorry no one's answered. I still use wet trojan 105s. I've used these for my boats and golf cart at home. I have a used sets of these older than 5 years and will continue to use them till I see a very noticeable reduction in the capacity. Or failures in a specific
battery. I don't see any reason to swap out just for the age factor. Just my opinion.

If you have a separate charger for your house and engine batteries (apart from the thruster charging system), and you are moving your house from flooded to AGM, consider that it's likely your charger can only output one charging curve at a time to all its banks. That means you'd have to change your engine bank to AGM as well if you want to maintain them with the proper charging curve. The two curves are pretty close but best to stick with the proper spec.

I am not a fan of AGM, have had issues with longevity in the past and for the price one pays for them one should be getting a longer life span. Also they tend to come in with quite less capacity compared to standard flooded batteries. As Viper mentioned, having different chemistries can create less than perfect charging however I did have a multi chemistry charger on my previous boat so yes there are some but far and few between. Here is one example of multi chemistry, even does Lithium. https://no.co/genpro10x4

Personally I don't have a problem with regular good quality ( trojan/rolls surrette) wet batteries, I would rather maintain them and know what I have. My guess here may be, you want to have all the same batteries, did you get AGM for the thruster, can't remember ? The charge curve is close but two chargers would be still fairly simple to deal with if you feel the need.

I guess for me if the install is simple and if placement is no problem then flooded would be my choice, no need to complicate matters.

I put Carbon Foam Lead Acid batteries in when I bought mine and happy with them so far. Quite a few benefits compared to the ol' regular wet lead acid technology. More expensive, sure.

Not sure I'd do it again given how much cheaper Lithium has become in recent years. It's really come down to the point where if you look at the longevity of lithium vs any LA battery, the lithium can't be beat. Then it's just a quick run of the numbers to see that lithium costs less and lasts longer.

Of course there are additional considerations as others have mentions (charge curves of chargers/solar controllers, starter bank compatibility, etc.)

Food for though.

Looks like i got you up front for some discussion now.

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Not sure I'd do it again given how much cheaper Lithium has become in recent years

I bought my Lithiums last fall and am just about to flip the switch on final install. I think I lucked out because finding Lithium batteries today is next to impossible to find as there is such a demand not to mention lithium has gone up no less than 10x since the beginning of 2022. https://finance.yahoo.com/news/lithium-prices-nearly-doubled-2022-170000490.html

Hi Bud, I did use AGM for the bow thruster LOVE them so far.