Pilotnut

I need help trying to understand what I have going on under my console on my recent purchase. I have all 4 batteries wired together (parallel), and 2 Perko swiches. Both switches have 4 positions, "1", "2", "All" and "Off".

I just keep both switches in the "All" position since I'm not sure out what purpose they serve if they are not isolating a single (or pair) of batteries.

The port side switch does act as a "cut-off" switch to the port side motor, same applies for the starboard side.

Here are a few of my immediate questions, I'm sure I will have more:

1. Is this the best (most common) set-up for a 4 battery, 2 motor application?

2. How do I know if one (or more) battery is weak or dead?

3. How do I hook up a charger in this scenario?

4. The Perko switches have 3 lugs on back, all of which have red cables attached to them. In my scenario, if these switches are simply acting as cut-off switches, is the third lug required in a "Parellel" wiring set-up?

Thanks for your help.

bradv

my guess is you have 2 battery banks. one switch does one motor and the other switch does the other motor. i doubt all 4 batteries are wired in parallel. However the grounds will be linked together but not the positives. the 3 lugs on the back of the switch are 1, 2 , and common. 1 is for the input battery of one battery bank. 2 is the input battery of another battery bank and the common is the output of the switch. so you can choose to run battery bank 1 or 2 or all and that is what is feeding the common on the switch. now what is hooked up to the common could be the motors house etc. what boat do you have good shot someone on here has it and can be more precise.

Pilotnut

I have a 1991 Mako 241 with twin 2007 Suzuki DF175s

ktugboat42

Get rid of one battery and go with one of these battery switches. One battery for each engine and one for the house.

I'm on a boat

X2. That is a two battery plus house VSR. That will solve all your problems.

yandina

Since you already have switches, you don't need to do a whole new installation. That is totally unnecessary.
First analyze each switch, turn them to OFF one at a time and see what no longer has power.
I suspect one will select which batteries your engine is being connected to and the other is selecting which batteries are being used for house.
Traditionally switch position 1 will be for starting battery and switch position 2 will be the house batteries.
Again typically, position 1 will be going to a single battery, usually a starting battery with high CCA but low amp-hours. Position 2 probably has the other 3 batteries in parallel and would typically be deep cycle.
Do some detective work and see if a Combiner has already been installed. It will be connected between the battery banks or between the "1" and the "2" terminal on one of the Perko switches.
If one is installed you should be able to set the ENGINE selector switch to "1" and the HOUSE selector switch to "2" and forget it. The Combiner will take care of charging the house bank battery(ies). You would only change the switch settings to OFF when the boat is out of use or to BOTH for emergency starting.
If you don't find one, a Combiner100 for about $65 is all you need to make charging automatic.
Although it does the same as the BOTH switch it automatically isolates the "1" and "2" battery banks automatically when the engine is not running. That way your house loads will never run down the starting battery and you will always be able to start your engine.

burgaud

Complete Wiring Diagrams here

PS. It is highly advisable to use VSR/ACR to manage charging of batteries.

saltwaters

One of the best things an owner of a new to them boat is, learn how the electrical system works. Get a piece of paper out and trace the main wires going to the switches and engines. You need to know what is attached to all of the batteries and switches and how the main panel get's it juice. There's no substituting a good working knowledge of this critical system. You might not need to remove or replace anything. If it was working for the previous owner it should work for you too.

chainsaw42

disregard the comment about removing a battery. eliminating a perfectly good battery and reducing your battery capacity makes absolutely no sense unless you're trying to reduce the weight of your boat which you're not.

yandina's post makes some sense--the part recommending some detective work to better understand how your electrical system is set up. but yandina is in the business of selling combiners so, like usual, the advice always ends up recommending you buy a yandina product. if you have 2 banks and 2 separate charge sources (2 engines), a combiner is completely unnecessary. borders on spam actually, again like usual.

what you describe the electrical system to be is very unusual...4 total batteries all wired together in parallel with 2 battery switches and all 3 lugs on both switches occupied with wires. either there is some confusion in the description or someone (previous owner?) messed with the wiring. are you sure the batteries are wired in parallel before the switches? (are all positives tied together 'before' the switch?). most likely the batteries are not (or are not supposed to be) wired in parallel, but are actually 2 separate banks, with one intended to be normally connected to the port motor & charging system and the other bank intended to be normally connected to the starboard motor & charging system.

as for your question about how to know if you have a single bad battery, you need to isolate each battery to test it. you can load test it at an automotive store (ok test), or you can test it yourself by discharging it at a known rate and monitoring the voltage vs. time. you would need a load (20 amp load is commonly used) and a way to measure the current and voltage. this is the most accurate way to measure the health of a battery but takes some equipment and some time so most just haul the battery to autozone and let them load test it there.

95SCARAB

I only have two batterys on my boat currently, but i would like to add a third for electronics, radio and what not on those long days out at the island. Who makes that isolater set up in your picture?

305seahunter

You can go to marinco's site. Or a distributer for the switches. Our contender has this setup and we love the simplicity of turning on the switches and not worrying

ColdWetDog

Or Blue Seas (they make the ACR, another common product).

patmcqueen

[OUOTE] It is highly advisable to use VSR/ACR to manage charging of batteries.[/QUOTE]

Why use a VSR/ACR vs. a battery charger with multiple banks?

Pat

alloyboy

Why use a VSR/ACR vs. a battery charger with multiple banks?

Pat[/QUOTE]

Lots of folks don't want or need to use an external battery charger. And if they do they might not want the type that will charge two, three or four batteries at once.

With a combiner/VSR/ACR whenever an engine is running the batteries will be paralleled so they all get charged. And if one has a simple external charger then it can get connected to one battery in which case they can all become charged via a combiner/VSR/ACR.

isitstuffed

I have seen this on Four Winns cruisers with twin diesels. They use remote controlled electrical battery switches controlled from the helm, but the principal is the same.
The idea is to cross connect the batteries so that either bank can start either engine. As opposed to paralleling all 4. This is preferred due to a battery bank having shorted cells and / or being flat and paralleling them all up will only make things worse.
I would hazard a guess the position 2 on both switches go to opposite engines.
The position ALL will enable one engine to charge both banks.

To confirm switch one battery off and the other to position 2 and see which engine cranks then repeat with switch in position 1 and see if the other engine now cranks.
The Four Winns website have circuit diagrams for owners of their boats.

LidoKey

Not sure I agree with that. One battery for each engine, yes. Eliminating one house battery? I don't think so. Too much load from today's electronics. VHF, chartplotters, fishfinders, live wells, stereo, etc. If there is room, and there is as the OP stated, he has 4 batteries, I'd opt for 2 house batteries every time. You know the old saying, "Can't be too rich, too thin or have too much battery capacity" That is the correct saying, right?