Building a battery bank

[Briankinley2004]

Just curious if anyone knows if you could successfully build a 32V battery bank using 2-12V and 1-8V battery. Its getting harder to find 8V batteries and when I checked into replacing mine last year I could only find one 8V on the shelf. Luckily I discovered my issue was not the batteries but a stuck starter. I know fitting them into battery boxes would be an issue but just asking in general if this would work or do all of the batteries in the bank have to be the same voltage.

[SKYCHENEY]

Its only possible if all of the cells are the same size; meaning they have the same AH capacity. Otherwise one battery will get overcharged/while the others are undercharged or vice versa.

[carolinacoast]

These are available.
https://www.trojanbattery.com/product/t-875/

year 3 with no issues.

[Photolomy]

These are available.
https://www.trojanbattery.com/product/t-875/

year 3 with no issues.

These seem a bit small. Do you use 4 of them per bank? Certainly would reduce weight.

[piripucha]

I did that for several years until it got almost imposible to get the 8V batteries (phisically and finantially). So I set up the battery banks to 36V. I had to tweak the charger and also change the Galley Maid head pumps breakers to a higher ratting. The system has worked quite well for almost 4 years.

[carolinacoast]

These are smaller. My surveyor liked the setup, since the CCA exceed what is needed, and they fully revover from discharge better than 8D.
My setup is unique, and similiar to a former owner MikeP. I have the banks combined with a switchable conbiner , which is safe, since I have a dedicated start battery on a #2 gen. We always run a gen away from the dock also.

[RonNP]

I get all of my marine batteries from Dyno, 8 volt, 12 volt etc. They deliver nationwide and are built in America.


http://www.dynobattery.com/

[Westfield 11]

Pascoe in Maryland also had Rolls 8v batteries in stock in May when I replaced my port bank. You might want to give them a call: their Rolls prices were very low this summer.

[Pascal]

When my boat was 32v I used 8V golf cart batteries. Most golf cart specialists carried them and they lasted 4 to 5 years. Never had an issue cranking the 8V71Ns. Boat was setup that way when I got her and it lasted 16 years or so before I repowered and switched to 12V for the engines and 24v for house.

[Guy Walters]

I bought two banks worth of (4) 8V each from Costco for $110 each back in the spring. They are Duracell golf cart batteries. They have worked great so far. You just have to check the water levels monthly. My battery banks are on both sides of the engine room floor so access is not a problem.