Dual Battery Set up

[Captaingregw]

Could someone please advise me if the below schematic I have drawn would work for a dual battery set up for my Mercruiser 3.0 Alpha One .Its a bow rider and would like the switch to be under my dash? As well because the distance from the battery terminals to the Switch will be approx 12 feet what guage cable should I use?

Thanks in Advance everyone
Greg

 

[Bondo]

Re: Dual Battery Set up

Ayuh,.... Put the switch near the batteries, Not at the helm...

Cabling of that size is Expensive,+ it's unprotected by fuses....

Putting the switch forward would be ridiculously Expensive, 'n a Fire Hazard...

 

[Silvertip]

Re: Dual Battery Set up

And why the expense of the VSR since you already have a switch. One or the other but you don't need both -- especially if the reason for the VSR is that you don't want to mess with the switch. As for cable size, that needs to be at least one or two gauges heavier than the current battery cables due to the length of the runs.

 

[Fed]

Re: Dual Battery Set up

Your schematic is flawed.

 

[bruceb58]

Re: Dual Battery Set up

I wouldn't mount the switch under your dash. The runs for the cables are just too long.

I run a switch and a VSR. Nothing wrong with that at all. I basically just leave my switch at #1 all the time and bot batterries always charge. My #2 battery is my backup.

 

[DaNinja]

Re: Dual Battery Set up

I was just looking at the third sticky in this forum as I look to put dual batteries in both boats. Good info... http://forums.iboats.com/showthread.php?t=239445

 

[rwidman]

Re: Dual Battery Set up

Ayuh,.... Put the switch near the batteries, Not at the helm...

Cabling of that size is Expensive,+ it's unprotected by fuses....

Putting the switch forward would be ridiculously Expensive, 'n a Fire Hazard...

Solid advice. Follow it.

 

[rwidman]

Re: Dual Battery Set up

The best solution would be the VSR plus an on/off switch for each battery and a switch (or jumper cable) to be able to use the other or both batteries to start the engine in an emergency.

Leave the engine and gauges connected to battery #1 (which should be a starting type battery) and connect all electronics, lights, accessories, etc. to battery # 2 (which should be a deep cycle battery).

 

[Captaingregw]

Re: Dual Battery Set up

Hi Fed

Why is the schematic flawed? please elaborate.

As well the local boat yard here says its perfectly fine to use a VSR and a Switch.

I was told start on Battery 1 then switch to all and the VSR will take care of the charging of both batteries and when stopped it will drop the starting battery when it falls below 12 V to ensure you will not drain your starting battery when you need it.

Thanks

 

[Fed]

Re: Dual Battery Set up

Hi Greg, my mistake mate, I misread your circuit.

Your local boat yard is flawed though.
When you switch to 'all' your vsr will have no effect on your charging or discharging.

I'd be going with either the switch or the vsr but not both.

 

[Captaingregw]

Re: Dual Battery Set up

Thanks Fed

This is what I was told to do?

 

[skargo]

Re: Dual Battery Set up

Get rid of the VSR IMO.

 

[bruceb58]

Re: Dual Battery Set up

If you have the VSR you don't have to mess with the switch trying to make sure you have both batteries charged. For example, you start your boat and switch to "both" on the way to your fishing spot. What happens if you forget to switch it back to #1 while you are running your bait tank all day. Both batteries could get discharged far enough that you won't be able to start your boat. Having the VSR and the switch is the way to go and is also the recommended set up by Blu Sea whose picture you used.

The only time you would ever need to switch to "both" would be when, for some reason, you couldn't start your boat from either battery by themselves.

The Blu Sea Switch that you have shown is different than most 1,2 both switches. When it is in the on position, it hooks #1 battery to the engine and #2 battery to the house circuits. When it is off it disconnects both batteries from their loads. The switch will have 4 terminals. In the combine it hooks everything together at once so you can start your engine off of both batteries just like the common 1,2 both switch.

A standard 1,2,both switch will have 3 terminals which are for connecting battery 1, battery 2 and a common terminal which would go to your starter solenoid.

If you don't have all your house loads separated from you engine, you want to go with the standard 1,2,both switch.

 

[skargo]

Re: Dual Battery Set up

If you have the VSR you don't have to mess with the switch trying to make sure you have both batteries charged. For example, you start your boat and switch to "both" on the way to your fishing spot. What happens if you forget to switch it back to #1 while you are running your bait tank all day. Both batteries could get discharged far enough that you won't be able to start your boat. Having the VSR and the switch is the way to go and is also the recommended set up by Blu Sea whose picture you used.

ORRRR, you could do what I do, start on #1 and run to your spot, then switch to #2 while you float, are anchored, whatever. Then switch to both for the run home. It's not rocket science, and it's really not hard to remember.
If you do it my way, and forget, you kill #1 and still have #2 for backup.
I don't see the need to over complicate things, but that's just my opinion.
The only time you would ever need to switch to "both" would be when, for some reason, you couldn't start your boat from either battery.

 

[Skiwi]

Re: Dual Battery Set up

For what its worth I went ahead with the set-up I was proposing here http://forums.iboats.com/showthread.php?t=444346 and am happy with it.

The only thing I could think to improve it would to have the automatic charging/switching, but as it is I only have to flick switches twice in a day (all on when running primary motor, starter battery off when primary motor off) so it's not a big inconvenience.

 

[Fed]

Re: Dual Battery Set up

If you're running on 'both' there's really no point in having the vsr.
I prefer having the control myself.

 

[bruceb58]

Re: Dual Battery Set up

ORRRR, you could do what I do, start on #1 and run to your spot, then switch to #2 while you float, are anchored, whatever. Then switch to both for the run home. It's not rocket science, and it's really not hard to remember.
If you do it my way, and forget, you kill #1 and still have #2 for backup.
I don't see the need to over complicate things, but that's just my opinion.
The only time you would ever need to switch to "both" would be when, for some reason, you couldn't start your boat from either battery.

Its not rocket science but it is also easy to forget to switch it back. We are talking $100 for the VSR. It makes it so simple. Have had mine for 10 years and can't believe I used to go through that switch hassle, especially on week long camping trips to the lake.

 

[Fed]

Re: Dual Battery Set up

The Blu Sea Switch that you have shown is different than most 1,2 both switches.

I didn't notice that Bruce, it changes everything.

 

[bruceb58]

Re: Dual Battery Set up

On my dad's boat, we had a fridge running off the #2 battery with and on/off switch. The VSR was awesome so we were always charging the battery while starting on #1. If you happened to leave the switch to "both", you would drain both the start and the fridge battery down to nothing.

 

[skargo]

Re: Dual Battery Set up

Its not rocket science but it is also easy to forget to switch it back. We are talking $100 for the VSR. It makes it so simple. Have had mine for 10 years and can't believe I used to go through that switch hassle, especially on week long camping trips to the lake.

Some of us don't find it a hassle at all. Like I said, just my opinion but I prefer simplicity, it's $100 I don't need to spend, that's for sure.