Battery Woes

[rperret]

Appreciate any troubleshooting ideas here.

I purchased two new deep cycle batteries to use as starting and house for my S2. Have had the batteries installed for less than a month - and they were purchased new less than one month ago.

Batteries appear to be wired in parallel - although when replacing the old batteries with new - I noticed the PO connected the two negative terminals together with a short battery cable - so i just duplicated that set up.

During first few times, I started my Yanmar 1GM on battery #1 - is cranked fine and started the motor (after solving my earlier banjo bolt problems). I finally tried to start using the #2 battery and noticed that it did not have the same degree of cranking power. After trying 2nd time, the #2 battery failed to start the motor. I switched my Perko selector to "all" and it fired up instantly.

I suspect the following, but need advice on testing properly:

1) battery - will check voltage and specific gravity to ensure I don't have a defective battery. (already know how to do this..)
2) is #2 battery somehow not getting enough amps thru to the starter? no idea how to test this? do I test this at the switch or starter?
3) could something be draining the #2 batter (even though I turn off the Perko switch) how could i test any voltage/amp leakage?
4) is the fact that I connected the two negatives together creating some odd set up that is causing problems with the #2 battery.

Any other thoughts?

Thanks in advance.

Rick

[timangiel]

The fact that you have a jumper between the 2 negative terminals has nothing to do with your problem, it suppost to be there. Before you get too involved I would try starting your engine with the Perko switch set to all and let it run for awhile. That should allow both batteries to charge. After a little while shut of the engine, set the Perko to 2 and see if seems any better. It may just need a good charging. You could also try swapping the 2 batteries, that is take your #1 battery and put it in place of the #2 battery. Since you already know #1 is good and if you put it in the #2 place, if it doesn't work there then you can suspect a problem in the wiring. If it still works just as well then you can suspect a problem with the original #2 battery. Let us know what you find out.

[sailingdog]

How are the positive terminals connected?? Did you want separate house and starting banks, or one large house bank. By having the batteries in parallel, as you say they are, you don't have two banks, but a single bank.

If what you want is one large bank, then the two positive terminals will also be connected via a short cable, if these are supposed to be connected in parallel... as you say. Then another cable should run to one side of the battery switch. The battery switch will then only work in that bank position or the both position, but not the other bank position... since there isn't another bank.

However, if you want two separate banks, then they should not be wired in parallel, and each battery's positive terminal will run to one side of the the main battery switch—giving you two banks, of a single battery each.

It sounds like the batteries are connected individually, not in parallel, and that you have two banks. However, unless you have a battery combiner... only the bank that is actively selected on the battery switch will charge if the battery switch is not in the "both" position. That is probably why the second battery sounded like it wasn't charged as fully as the first battery, as it isn't be charged when the engine is running...and may be supporting the loads of the house bank as well.

[hellosailor]

And, it could also be a simple bad cable (did you re-use the old cables?) or loose or corroded contact. You can't make *any* assumptions about battery wiring, the best thing is to eyeball the entire charging system, inch by inch, especially the spots that are hard to see. And confirm they are all clean and tight where connected.

We ignored one contact, because it was "just" the primary ground bolted to the rear of the engine block, where no one could reach it. And happened to notice one day that it was making huge yellow sparks--because it was loose.

Oopsie. That's been redone and secured with star washers now, too.

[camaraderie]

Rick...I'm with Dawg on the diagnosis. Here's an example of what you might want to do with your system:


Other possible options are illustrated here:
Marine Battery System Hookups

[sailingdog]

Nice page link Cam... quite useful.

[camaraderie]

Yeah...I bookmarked that one as we get so many questions and the pictures of different options are so much simpler than trying to explain it and my drawing skills are non-existent!

[rperret]

thanks all. will try swapping the #1 battery and #2 - this should be a first acid test (no pun intended) as to where the problem is - can do this tomorrow before my Wed nite beer race and will report back results (of battery test, not the race...)

Rick
S2 27

[dougyoung]

Go to the Blue Sea web site and look at the wiring diagrams fro their e-series switches and the ACR battery link. I installed both of these and life could not be better. Blue Sea will also answer all your questions for 12v battery management and set up.

I bought all the equipment form Jack Rabbit Marine. They also provided excellent support. Ask for peter.

[rperret]

Just when you think something doesn't work it seems to work now.

At any rate. I tried restarting on #2 only - and guess what - it fired up. I shut down after 3 min. Checked voltage on both batteries - (started with Perko set to #2). #1 showed 12.62 volts, #2 was 13 volts.

I am now thinking what happened. When buying both batteries - i trickle charged the #1 before installing and uswed the #1 for starting - for 3-4 sails. THen tried the #2 when it would not start. So maybe it just needed a charge.

We'll see how it goes. At this point, I am going to purchase a Blue Sea Battery Isolator to handle battery management.

Thanks again all for input.

Rick