need new batteries

[km1125]

Does anyone else think it's crazy for the genset to have a group 31 battery??? THAT motor (what is is, about 40 hp??) should really just have a small starting battery... should not even have to be a group 24. Then repurpose that Group 31 and parallel it with one of the other group 31's into your "house" battery.

Doesn't solve the engine/house battery problem, but I'd probably replace that switch with the blue seas dual circuit switch and be done with it!

[bud37]

Source of the post Does anyone else think it's crazy for the genset to have a group 31 battery??? THAT motor (what is is, about 40 hp??) should really just have a small starting battery... should not even have to be a group 24. Then repurpose that Group 31 and parallel it with one of the other group 31's into your "house" battery.

Doesn't solve the engine/house battery problem, but I'd probably replace that switch with the blue seas dual circuit switch and be done with it!

Yup, Im with you.......I replaced mine with a lawn tractor battery, gen can charge itself......it is in reality just a two cylinder yard engine that needs only about 300 cca.Clears up some room.......

[Viper]

You don't need a group 31 but personally I wouldn't go with anything less than a 24 group. I don't use anything under an 800MCA for anything anymore including a generator. Small engine or not, that peice of equipment can get you out of a real jam in the perfect storm so I want to make sure there is plenty of power/reserve to get it going and keep it running especially with today's computer controled units, they don't like voltage drops and will trip a code if it happens. Also consider that a battery will naturally discharge on its own, unless your charger is maintaining it regularly, it will discharge to a critical level sooner than a larger battery. This happens quicker than you think in hotter temps outside and in the engine compartment when running the mains. If you don't run the genny often (pretty common), this can be a problem. A 31 is uncommon for this app but there's nothing wrong with overkill when it comes to batteries IMO.

[km1125]

Source of the post You don't need a group 31 but personally I wouldn't go with anything less than a 24 group. I don't use anything under an 800MCA for anything anymore including a generator. Small engine or not, that peice of equipment can get you out of a real jam in the perfect storm so I want to make sure there is plenty of power/reserve to get it going and keep it running especially with today's computer controled units, they don't like voltage drops and will trip a code if it happens. Also consider that a battery will naturally discharge on its own, unless your charger is maintaining it regularly, it will discharge to a critical level sooner than a larger battery. This happens quicker than you think in hotter temps outside and in the engine compartment when running the mains. If you don't run the genny often (pretty common), this can be a problem. A 31 is uncommon for this app but there's nothing wrong with overkill when it comes to batteries IMO.

Considering you have limited space in the bilge and a LOT of other use for a group 31 (house), even the biggest genset on pleasurecraft could easily use a jetski battery for the genset. Plenty of power and reserve to start a 20-40 HP engine and small enough that you could mount it anywhere.

[bud37]

I thought much the same about the generator battery until I read the manufacturers (Kohler, Kawasaki ) spec requirements, I realized it is nothing more than a small tractor (ATV) engine......I have the 7.3 Kohler ,3600 rpm, 16 HP, minimum battery spec is 260 CCA......I currently have ,if I remember right 345 CCA. I will be the guinea pig here, lets see after a season if all is well, so far so good. In the space where there used to be the giant gen battery is now a main engine start and the gen start, with some room if I need to go to a larger engine start or gen start, with all the same cables.

[Viper]

Some specs need consideration and adjustments to its working environment and the quirks of real world conditions.

Deal, you'll be the guinea pig! Will be interesting to see how long it lasts trouble free.
Will you be leaving it in the boat all winter long?
Is your house charger hooked up to the genny battery?

[Viper]

Source of the post ...even the biggest genset on pleasurecraft could easily use a jetski battery for the genset....

We'll just have to agree to disagree on that one.

[PhilH]

Just my opinion, but the bigger the battery capacity, the better. Like a group 31 will last years longer than a smaller car type battery, and if a main engine battery wont start the group 31 size would work with no problems. Plus, the cost is not that much more and effort difference to me to remove/replace batteries is a lot of work.
Hope this helps
Phil

[km1125]

Source of the post Just my opinion, but the bigger the battery capacity, the better. Like a group 31 will last years longer than a smaller car type battery, and if a main engine battery wont start the group 31 size would work with no problems. Plus, the cost is not that much more and effort difference to me to remove/replace batteries is a lot of work.
Hope this helps
Phil

Then why aren't you guys using 8D's for all your applications?

[AaHubb]

km1125, I tried a 4D one time but found I could barely lift it onto the battery shelf while hanging upside down into the engine compartment.
..Aaron