Dual Battery Set Up In Boat

[hoges1974]

No doubt heaps of you guys have 2 batteries set up in your boat my question is what set up did you go for. I have seen the electronic controls that swap from battery to battery when needed or you can have the manual switch

please share what set up you have and if you have any dramas

Edited May 11, 2008 by hoges1974

[pelican]

Dual independent charging circuits for start batteries, dual manual isolation switches. 3rd isolated battery for all access on overnights.

Not sure what motor you have or what electrical load on your boat.

If you don't really need it don't go to the expense.

All boats with a battery should have a isolation switch- many are fitted with the 2 poition ones as standard.

Smaller newer outboards can be started and run without batteries - check your manual to see if yours can and give it a go so you know how to do( if anything) it if you have a failed battery. Some brands of larger motors either built in or offer a dual battery charging circuit which isolates and charges each battery seperately.

A quality marine starting battery of a correct size and style that can be charged by your motor is enough for the usual loads and overnights. If you are using electric troll motor then you will need a different style of storage battery for good performance and have to home charge as many outboards can't charge them well or fully.

If you have loads of accessories or need a 2nd battery to get you home make sure it is set up properly and independently as it is your backup. Many people get caught with 2 flat batteries due to poor set ups. Make sure any electric switches or "roll over charge" switches are marine grade and placed in a well protected spot.

If you can say what you want to achieve someone will probably be able to say how they set it up and any issues they have had. Simple is always best with electrics and water.

Edited May 11, 2008 by pelican

[hoges1974]

Dual independent charging circuits for start batteries, dual manual isolation switches. 3rd isolated battery for all access on overnights.

Not sure what motor you have or what electrical load on your boat.

If you don't really need it don't go to the expense.

All boats with a battery should have a isolation switch- many are fitted with the 2 poition ones as standard.

Smaller newer outboards can be started and run without batteries - check your manual to see if yours can and give it a go so you know how to do( if anything) it if you have a failed battery. Some brands of larger motors either built in or offer a dual battery charging circuit which isolates and charges each battery seperately.

A quality marine starting battery of a correct size and style that can be charged by your motor is enough for the usual loads and overnights. If you are using electric troll motor then you will need a different style of storage battery for good performance and have to home charge as many outboards can't charge them well or fully.

If you have loads of accessories or need a 2nd battery to get you home make sure it is set up properly and independently as it is your backup. Many people get caught with 2 flat batteries due to poor set ups. Make sure any electric switches or "roll over charge" switches are marine grade and placed in a well protected spot.

If you can say what you want to achieve someone will probably be able to say how they set it up and any issues they have had. Simple is always best with electrics and water.

Thanks for the reply i have added more info

I have a 90 Optimax and i have heard of all kinds of stories about people getting caught out on the water at night with a flat abttery which i don't want.

All i run at night now is

Anchor light

2 way

plan to instal in the future

cd player

fluro lights (2 or 4 small ones)

i know it aint much but would hate to be stuck with a flat battery

[pelican]

Hi

That's not much of a load and I would rather have a single large well charged and maintained battery than 2 that are average and badly set up with all the expense if yiou aren't using them regularly. Good quality LED are better than the flouros now as they draw less and don't corrode- they ain't as cheap though.

One mate when he knows he is doing a overnighter simply takes along a spare battery and has a set of anderson plugs on it. At his switch board he has a isolation switch and the other half of the anderson plugs. It's wired so all accessories off the switchboard run off the spare battery ( but it doesn't get charged and isn't connected to the motor) and the motor stays connected on the fitted original battery. That way if an accessory shorts or draws a big load like when you have abba at full blast through theh mega speakers you will always have a good start battery. The spare battery could be used as a jump start battery as required. Like with all 10kg items make sure it is a sealed lead acid and secured well. I probably have a sealed lead acid storage battery avaliable if you wanted one- you just have to remember to charge it slow low amp at home.

I think an 90 opti is hand startable - a mercuy man on here or your manual will have the details and the physio on your shoulder and back won't cost much. The only issue is that I believe the battery must still have all cells working and just be flat as it need some voltage to keep the computer "warm" otherwise it won't kick but don't quote me on that.

Pel

[a boat]

Hi Hoges, Pel has answered most of your questions well. Your current draw at present would not be a strain on a well maintained marine battery, but as you add more components there is always more draw on the battery. Also unfortuanetly a battery can just fail without any real warning, so going out at night without a twin battery set-up can make it a cold and lonely night until help comes in the morning.

To fit a twin battery system, get your self at least a 640CCA second battery(which I hope your existing battery already is), and the best way to wire it up is with a isolation switch complete with a VSR. This set-up will look after the charging of both batteries automatically, but also allow you to switch from one battery to the other if need be and also shut the system down when not used. It is not the cheapest way to do it, but it is the best. The switch with VSR will cost about $190 and a good quality battery will be about $170 and about $50 worth of battery lead and you will be good to go.

One last point, your OPTI will not be able to be rope started in an emergancy due to the engine needing to be cranked for a few revolutions before the comperssor builds up enough pressure to run the DI system. You are not alone all other "clean" engines except one can not be rope started or run with a good battery.

Cheers,

Huey.