Dual Battery Problem

[MJHSupra]

My set up is very similar to what you have. I scoured the forums several summers ago and decided to go with a Blue Sea "add a battery" kit. It includes a switch and a automatic charging relay. I haven't changed a battery since. I've attached a link to the kit and the schematics of how I have hooked up my dual bank charger.(diagram is copied from someone else.... not my idea or effort! I hope this helps.

https://www.westmarine.com/buy/blue-...75?recordNum=1

Attachment 25283

I also use the Blue Sea Add-A-Battery System with 2 Stereo (acting as one) and 1 Starter battery.

I'm have a Inteli-Power smart charger connected to the batteries.

MLA will probably tell you there are >1 way to wire depending on what you are doing. Follow his advise.

There was 4 connections on the switch and 2 on the ACR. My boat is not in my garage, but I'm pretty sure I used what was listed on the install directions for the system.

Installation Instructions Features and Specifications for Add-A-Battery 7650 - Blue Sea Systems:

https://www.bluesea.com/products/765...ery_Kit_-_120A

Download the PDFs.


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[MLA]

You'd also have the option of connecting your accessories like amps directly to #2 battery terminals if it's more convenient. The risk is that if you have some constant load, it would drain that battery and you wouldn't have a way to disconnect it.

Which would like the OP has and the reason for the thread.

This method also forces the operator to leave the switch on the BOTH or #2 position while the boat is in operation, or the house bank goes dead after awhile because the alternator is not contributing if the switch is in the #1.

No advantage to circumvent switch, only cons.

[jstenger]

Aight guys I need some help. Every year I have to buy 2 new batteries because I apparently have a short somewhere.

I have a dual bank charger that I usually plug in but I forgot all about it in October. Check the boat yesterday and both are batteries are done! Took em back to Napa and they are gonna switch em out for half price.

My question for you guys is what is the best way to hook my gear up.

Exile System, LEDs, and we mainly surf and sit listening to music. I've never ran em dead. I also have a perko switch to use each battery separately or together. I have always ran both batteries parallel (pos to pos, neg to neg) then hooked up engine start to one and radio/led to the other and then attached dual charger to both....

Is this a correct setup or is there a better way!?

I'll be picking up new batteries today and will wait to see what you guys recommend before hooking everything back up

Thanks in advance! Sorry for not being around much, been a busy year


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Please post a wiring diagram of your setup and a picture or name of your switch. It sounds like yours is wired like mine. I turn my switch off everytime I leave the boat and also leave it off all winter long. I only combine when driving. NEVER combine when charging with a dual bank charger.

[lee]

I also have a perko switch to use each battery separately or together. I have always ran both batteries parallel (pos to pos, neg to neg) then hooked up engine start to one and radio/led to the other and then attached dual charger to both....

Is this a correct setup or is there a better way!?

If the batteries and wired together, why do you have a switch and what can/could it do?

[tgoody14]

Sorry got busy again.

So i tried finding the switch online, it's not a perko but it has a 1, 2, All, and Off on the switch.

When I bought the boat it already had 2 batteries with a stereo and amp already hooked up to an "accessory" battery and just the engine hooked up to an "engine" battery. The amp and Stereo negative cables were connected directly to the negative posts and the positives on both batteries have fuses. These two batteries were wired parallel into each other then positive cables into the not "perko" switch.

When I added LEDs and more speakers and an additional amp I just added everything to the accessory battery.

I then added a dual battery charger thinking this would help keep both batteries charged up when I'm off the water. Which I normally plug in after every use and the batteries have done great.

So at the end of October I put the boat up but did not turn the switch to Off nor did I plug the charger, soooo the batteries slowly died. Napa was able to charge the batteries back up over a days time and they now hold a strong charge so I'm going to put them back in the boat.

After reading everyone's input, I think I should remove the parallel connection. Run the batteries separately (1 for engine, 1 for stereo/lights) but still use the switch and the dual charger...

Clear as mud!?!?

Thanks for all the help, keep the information coming if I should do this differently


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[lee]

Removing the positive wire that connects the two batteries would be the correct way,

[jstenger]

You appear to have a factory type switch. Keep the negatives tied together. One battery needs to go to the #1 post on the switch and the other battery needs to go to the #2 post on the switch. The third post on the switch should ONLY go to the starter and positive bus behind the helm which controls the bilge, starter, lights, horn, pumps, etc. The stereo and amps positive AND negative NEED to be directly wired to one of the batteries. Just pick one. If both batteries are identical then it doesn't matter which one you choose. Only problem is that the stereo will draw a slight amount from the battery that it is hooked to because of the memory wire. Make sure your switch is OFF when using the dual bank charger. It can be in the BOTH position while driving the boat.

[dusty2221]

Definitely do not do the above, do not wire amp b+ direct. Follow this basic guide:

First, the engine block ground, helm negative ground buss, all audio grounds, and battery to battery grounds, are all common at the batteries.

The dual battery switch (Perko) will have a battery #1 post, battery #2 post, and an output post.

Battery #1 post direct to battery #1.

Battery #2 post direct to battery #2.

The alternator/starter feed, helm positive buss/fuse panel (which also has a breaker at the battery supply end), and ALL audio electronics positive supplies will be connected to the dual battery switch output post.

Nothing will be wired battery-direct beyond the dual battery switch posts #1 & 2, a bilge pump/float switch if applicable, and the option of the source unit memory.



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[MLA]

Yes, wiring the loads direct to the battery puts you right back where you are now, circumventing the switch. ALL loads need to be wired to the common post of the switch. I even like the radio MEM to go there in most cases. The only exception would be the auto bilge lead. wire it battery direct.

Charger wires to the batteries, but keep in mind, its not a load, but a supply.

[jstenger]

I do not disagree with Dusty or MLA's logic, but I thought the whole point of two or even three batteries was to keep the stereo and amps separate from the engine.....
Please explain so I am not missing something.