Perko dual battery switch

[Father's Day]

Hello everyone I have a quick question I'm installing a Perko dual battery switch and just wondering is it a good idea to put it on all when you're running to have the alternator charge both batteries
Thanks in advance

 

[leeccoll]

Hey Father's Day,

It's best to use the switch on dedicated 1, or alternatively 2. Not on both, you don't want to have a situation where you loose juice on both batteries and can't start your engine.

Grady White posts this on their website.

Happy Labor Day weekend~

Lee

Why Not Run Engine with Battery Switch on

I would like to know why not run engine with battery switch on

www.gradywhite.com

 

[Father's Day]

Hey Father's Day,

It's best to use the switch on dedicated 1, or alternatively 2. Not on both, you don't want to have a situation where you loose juice on both batteries and can't start your engine.

Grady White posts this on their website.

Happy Labor Day weekend~

Lee

My real concern are both batteries charging while I'm running off the alternator or just the one I selected
( 1or 2) and by putting it on all would that then be charging both I will be using 1 for starting and 2 for accessories when I'm drifting or anchored

 

[Doc Stressor]

You are only charging one battery at a time when you are on #1 or #2. But it's much safer to run that way because a dead cell in one battery can't drain the other one. Only use the both position when both batteries are low and you need the two of them to get you started.

The best solution is an ACR. That way you will automatically switch to the both position as soon as the relay senses current flow from the alternator. The batteries will remain isolated so that a weak one will not discharge the other.

Blue Sea ACR

 

[Dennis K]

Place one switch on #1 and the other on #2 and forget it. Dont use “both” unless you have to. Never switch through “Off” with the engines running or you will blow the power heads.

 

[luckydude]

I have one of these mounted next to the batteries. It is supposed to be "smart" and only charge when they need it. If their indicator lights are to be believed, it works.

https://www.amazon.com/gp/product/B000NCOKV0

And like others here, I try and alternate batteries each trip.

 

[Doc Stressor]

That's a battery charger. It won't help you if you aren't connected to shore power.

 

[luckydude]

That's a battery charger. It won't help you if you aren't connected to shore power.

Yes, I'm aware. The point is to leave the dock with two topped up batteries. The boat can sit for a while between trips.

I like the ACR, it's on my TODO list. That's belt and suspenders.

 

[Blaugrana]

So I always thought you should never run on both and alternate trips between battery 1 vs 2.

My mechanic altered my switch setup after installing a cranking battery. His advice was to always start using the cranking battery, switch to house when drifting and use both when underway.

I feel like there is a split here between folks that say to do this vs don’t use both. I don’t have an ACR and have an OX66.


I can’t wait to install the Blue Sea Add a battery this off season and be done with this debate.

 

[SkunkBoat]

Its amazing to me that this is always a question. The Yamahas have an Aux Charging circiut feature for charging two batteries separately at the same time. All that is required is a cable. Yet it seems the dealers never install or suggest it. The idea that you would have to remember to switch batteries to charge them is just stupid. And you should not run on both because if you have problems, BOTH will be run down and you will be stranded. An ACR (with SI) is another way if you don't have the cable.

The other thing to note is that Grady wires the House circiut to be powered by whichever battery that is connected to the motor. This is because they don't have an ACR or an Aux charging cable so its the only way to always have House power. When you have an Aux cable or ACR, you can separate the function of the batteries to make make one a STARTER battery and one a House battery. You do this by moving the house feed from the "Feed" of the battery switch to the positive terminal of the HOUSE battery. This makes your house run on a different battery than your Starter circuit. You don't have to remember switching anything. You won't be cycling down your starter battery by running the house with the motor off. The switch will still enable you to use either battery or both for starting.