Which one is house batt

[Farandaway]

So—- I’ve got 3 batteries in my engine compartment. Two are deep-cycle, one for each engine and then one dual purpose that’s attached to the generator and also has connections for the bilge pump etc. Is this the one that is referred to as my house battery? If not, which one supplies power to all the 12V receptacles, gauges, etc.?

 

[SteveK]

deep cycle batteries are usually for house.

Deep-Cycle Batteries

Trolling motors and other accessories sip power at a slower rate for extended periods. Batteries that power them usually aren’t recharged until the end of the day. These deep discharges are hard on battery plates, so deep-cycle batteries have fewer yet thicker lead plates than cranking batteries and are built to withstand deep cycling.

A deep-cycle battery’s reserve capacity (RC) rating indicates how long it can carry a specific load before falling into the dead zone. The higher the RC number, the longer the battery will power your accessories. Remember this when choosing a battery. Typically, a deep-cycle battery will have two or three times the RC of a cranking battery. A deep-cycle battery also can withstand several hundred discharge/recharge cycles, while a cranking battery is not designed to be totally discharged.

Dual-Purpose Batteries

It’s usually best to install separate cranking and deep-cycle batteries. If your boat is small, however, and there’s only room for one battery due to space or weight restrictions, consider buying a dual-purpose marine battery specially that handles starting and cycling. Bear in mind, however, most dual-purpose batteries won’t start an engine quite as well as a true cranking battery and won’t endure as many deep discharge/recharge cycles as a dedicated deep-cycle model.

 

[Xlantic]

So—- I’ve got 3 batteries in my engine compartment. Two are deep-cycle, one for each engine and then one dual purpose that’s attached to the generator and also has connections for the bilge pump etc. Is this the one that is referred to as my house battery? If not, which one supplies power to all the 12V receptacles, gauges, etc.?

It could be any of the three. You have to follow the wires to see which one leads to the 12V panel. Or you can disconnect them one at a time to see which one feeds the house.

In my boat I have four battery banks: one for each engine, one for the generator and one for the house. For the house I have 8x6V "golf cart" batteries.

One battery for the house seems a bit light ...

 

[Farandaway]

It could be any of the three. You have to follow the wires to see which one leads to the 12V panel. Or you can disconnect them one at a time to see which one feeds the house.

In my boat I have four battery banks: one for each engine, one for the generator and one for the house. For the house I have 8x6V "golf cart" batteries.

One battery for the house seems a bit light ...

Unfortunately I don’t have a 12V panel. Without disconnecting the batteries how can I find out which one is the house? Engine batteries only have cables to engine and wires to the charger. Dual purpose has wires to generator and wires to charger with connections for the bilge pump.

 

[MYTraveler]

Sounds like your setup isn't right. The deep cycle should be for house, and the higher CCA battery for engine starting. Its a whole can of worms to make sure the charging is proper. Worth spending the money to get a guy who knows what he is doing.

 

[Farandaway]

Sounds like your setup isn't right. The deep cycle should be for house, and the higher CCA battery for engine starting. Its a whole can of worms to make sure the charging is proper. Worth spending the money to get a guy who knows what he is doing.

Now that’s what I have read. That deep cycles were for house and higher cold cranking amps from a dual purpose was need for starting. Unfortunately the marina where I used to be replaced the starboard battery with another deep cycle and I was told my port battery was bad and replaced it with another deep cycle because that’s what was there. So I’ve got two practically brand new batteries and they both may have not needed to be deep cycle.

 

[Xlantic]

Now that’s what I have read. That deep cycles were for house and higher cold cranking amps from a dual purpose was need for starting. Unfortunately the marina where I used to be replaced the starboard battery with another deep cycle and I was told my port battery was bad and replaced it with another deep cycle because that’s what was there. So I’ve got two practically brand new batteries and they both may have not needed to be deep cycle.

I suspect you will need to redesign your battery set-up and when you do that you will probably find use for the deep cycle batteries.

You should read through the archives here as there has been a lot of discussions on ho to do this. You should also invest a couple of hours on this website: https://marinehowto.com

One option that is to use the two deep-cycle batteries for house and starting one engine and you get a new start for the other engine (or share the generator battery for that engine).

 

[Xlantic]

Unfortunately I don’t have a 12V panel. Without disconnecting the batteries how can I find out which one is the house? Engine batteries only have cables to engine and wires to the charger. Dual purpose has wires to generator and wires to charger with connections for the bilge pump.

Do you have a fridge? Where that does connect to? What about lights and instruments. Maybe there is a house bank somewhere that you haven't discovered .

I would disconnect batteries and see what stops working.

 

[SteveK]

You have the option of moving cables around.
Make the dual use battery the only start battery for engines and generator. I have the last 8D serving that purpose for as long as it lasts. With two engine alternators I start the engine dedicated to charge the start battery first, then the other. The 2nd engine is dedicated to charge the house. With switches that can be altered.
Sounds like you have 12V deep cycle so parallel those and feed the house 12V.
With your description so far the house 12V must be fed off a connection point at the engine, a busbar? you should have a group of fuses tough.
Does not sound as though you have an inverter, just gennie.

ETA: Xlantic beat me to it

 

[Bacchus]

If no 12V panel what does the house consist of and are they all individual inline fuses?