Battery Replacement Questions

[jamoore]

I have a 2004 Mainship trawler with twin Yanmar Diesels. We have owned the boat for about 18 months. Last time we went to take the boat out in early December one bank would not turn over its engine. I was able to use the parallel switch and fire it up. I have original style 4-6v batteries for all 12 volt systems. I have a dedicated single 12 volt battery for the generator.

I want to replace all 4 6 volt batteries and am looking for some guidance. I have all the original documents that came with the boat and they say nothing about the size/type/capacity of the 6 volt batteries. The batteries that are there are "ELECTRO" distributed by E.B.S. Inc, and have D13 sticker on the side. Aside from that, I see no information on any specs. An internet search does not produce any info on either Electro or EBS.

I am fine with keeping the original setup of the 4 -6 volt battery set up. We have not and will probably not anchor out overnight. Our overnights have been at marinas with shore power hook-up.

I need advice on what type battery I need to get and where are the best places to buy them. I have done some searching and there seems to be a lot of various discussions on batteries and comments about 6volt vs. 12 volt and dedicated starting batteries and separate house batteries. I am fine with keeping it the way the manufacturer designed it. Just want to know what replacements I need to get and best place to get them. I have seen comments about batteries from Costco and Sam's and have easy access to both if that is the way to go. Thanks in advance, Joe

 

[High Wire]

4- 6 volt golf cart batteries are about $100 each almost anywhere. Anywhere there are golf courses you will find suppliers. That should give you 400-450 Amp-Hours capacity of which half of that is normally usable in everyday use.

 

[Pack Mule]

I need to replace my house bank also ( four six volt golf cart ). I’ve decided on Trojan 105. I think we have a similar problem which is we’re not asking our house bank to do any work. I believe I’m shorting the life by not cycling them. I’m just trickle charging them with shore power. I plan on cycling my new ones. I will probably replace this spring.

 

[ranger58sb]

I want to replace all 4 6 volt batteries and am looking for some guidance. I have all the original documents that came with the boat and they say nothing about the size/type/capacity of the 6 volt batteries. The batteries that are there are "ELECTRO" distributed by E.B.S. Inc, and have D13 sticker on the side. Aside from that, I see no information on any specs. An internet search does not produce any info on either Electro or EBS.

I am fine with keeping the original setup of the 4 -6 volt battery set up. We have not and will probably not anchor out overnight. Our overnights have been at marinas with shore power hook-up.

I need advice on what type battery I need to get and where are the best places to buy them. ... I have seen comments about batteries from Costco and Sam's and have easy access to both if that is the way to go. Thanks in advance, Joe

Given no labeling on your current batteries... and given that 4x 6V GC2s (golf cart batteries) is a very common solution...

Maybe you could measure you batteries, compare to BCI Group GC2 measurements, see if what you have are GC2s...

And then if so, wander down to the bulk stores and pick. Reading suggests GC2s by Trojan or East Penn/Deka would be good if you're OK servicing wet lead acid batteries.

If you batteries DON'T match GC2 size specs... then maybe there's a way to figure out what you've got using a BCI chart. (Could be a taller 6V, like L16? Et cetera.) And/or use a search engine and look for Electro, EBS inc, and.or D13, see if something useful pops up...

-Chris

 

[ranger58sb]

I believe I’m shorting the life by not cycling them.

Don't think I've ever heard that being a thing with lead acid batteries. Used to a NiCad thing?

-Chris

 

[jamoore]

Thanks

Much appreciated. Exactly the kind of info I was looking for. New I could find the right knowledge and info here. Joe

 

[Pack Mule]

Don't think I've ever heard that being a thing with lead acid batteries. Used to a NiCad thing?

-Chris

Ok that’s good to know. I was thinking I was just cooking them by never asking batteries to do anything but accept a charge. We’re never on the hook more than a few hours and then we’re only using house bank for the head.

 

[DrissZougari]

why don't just buy two Deep cycle group 31 (highest Amp/hour that you can afford $$$$$$). everything on your boat is protected with a fuse/Breaker for any overcurrent. also, everything on the boat including the engine will pull out of the battery what it needs to operate (think of the battery as current supplier for your equipment when requested only). you can put as many batteries on your boat as long as your charging systems are satisfactory and your boat can handle the weight as well as the space needed (weight is the most important factor when it comes to batteries on boats).
also, must keep any battery configuration at 12v (use paralleled connections only).

 

[Xsbank]

I don't agree with using golf carts for start batteries, I would rather have a dedicated bank that has nothing else connected. If you kill your house by failure or error, with a dedicated bank you can get back home. Also, golf carts are deep cycle which means the heavy loads of a starter motor can damage them or shorten their lives anyway. Start batteries suck for house service too.

 

[tiltrider1]

why don't just buy two Deep cycle group 31 (highest Amp/hour that you can afford $$$$$$). everything on your boat is protected with a fuse/Breaker for any overcurrent. also, everything on the boat including the engine will pull out of the battery what it needs to operate (think of the battery as current supplier for your equipment when requested only). you can put as many batteries on your boat as long as your charging systems are satisfactory and your boat can handle the weight as well as the space needed (weight is the most important factor when it comes to batteries on boats).
also, must keep any battery configuration at 12v (use paralleled connections only).

Group 31, 12v deep cycle batteries are going to give you about 105 amp hours but you can only use about half that. GC batteries are 6v, you need two for 12v use. You are going to have 230 amp hrs for which you can use about 70%.

Two - 12v batteries at 105 ah each = 210 of which you can use .5 = 105 useable.
Two - GC batteries at 230 ah each = 230 at 12v of which you can use .7 = 160.

The real key is durability of the GC batteries.

 

[Bacchus]

See. https://marinehowto.com/what-is-a-deep-cycle-battery/
GCs are about the lowest $/AH
Great service and durabiliry.

 

[dhays]

I am a little confused by your setup. It sounds as if your house bank is 4x6v GC batteries. What battery bank is used to start your engines? Do you have dedicated 12v start batteries for each?


As for your 6v batteries, I had 2 x 4D batteries on my sailboat that I replaced with 4 x 6v GC batteries. I used batteries from Costco and they were great. Cheaper than Trojans but more than adequate for your needs.


For your engines, I would use whatever setup was in your boat to begin with. It sounds like your needs are relatively straightforward and you don't want to get into the weeds on batteries. If your start bank is current another 4 x 6v bank, then just use Costco or Sam's Club batteries there. If the engines currently use 12v start batteries, then go with those. As was mentioned, a Group 31 is likely all that would be needed to handle your starting needs.

 

[Bacchus]

Mainship did a weird wiring scheme by combining house and start. Two banks but they each do both. I usually leve them combined to maximize the SOC and rely on the gen as the fsilssfe backup if mains have difficulty starting.