Battery Help

[ystribling]

Hi, I was hoping someone could help me with a battery, wiring issue.  I have an older Tracker with a new MotorGuide 46 lb trolling motor on it.  We have 3 batteries on board: 1 Cranking battery and 2 Optima Trolling batteries.  Also have a 3 bank charger on board.

We hooked the trolling batteries up parallel and they ran great this weekend.  We plugged in the charger at the end of the day but a few hours later we noticed that the batteries were putting off a sulfur smell and the battery compartment was very warm.

Any ideas of what happened?  I fear that 1 or 2 of my expensive Optima batteries has been fried. 

[-Joe-]

We hooked the trolling batteries up parallel and they ran great this weekend.  We plugged in the charger at the end of the day but a few hours later we noticed that the batteries were putting off a sulfur smell and the battery compartment was very warm.

Any ideas of what happened?  I fear that 1 or 2 of my expensive Optima batteries has been fried.

Parellel or series? Parallel would mean your running the TM at 12 volts instead of 24V. Not sure what the charger would do with them being paralleled, thats the same a putting two banks on the same battery.

Joe

[ystribling]

trolling motors are wired parallel and each has a charge bank connected?  Did that charge them at 10 amps 24 volts?  and or fry them?

[Creel Limit Zero]

what is the amperage per bank on the charger?

[ystribling]

I am pretty sure they are 5 amp banks

[Creel Limit Zero]

Gotcha, what you want to do is disconnect the parallel connection before you plug in the charger, or you want to just use one bank for both batteries.  When you have both batteries set up parallel, it is basically now just one big battery.  Hooking up 2 banks to one battery is not good. 

So if you want to keep both banks going to make the charge go quicker, you should get some quick connectors to break the parallel connection before charging. 

[ystribling]

Thanks.  They are 10 amp banks so would that send 20 amps to each trolling battery wired parallel?  If so would that explain the sulfur smell?  How can I tell if that fried the batteries and or charger?

Thanks a lot for your help

[ystribling]

Also.  If I do only want 1 bank to the parallel trolling batteries what do I do with the leads from the 3rd bank?  DOesnt seem safe to have them just wagging around.

[bassindude]

Wrap them in tape or shrink tube.  they should be ok.

[ystribling]

Thanks for all the info.  Much appreciated.  1 last thing.  How can I tell if the 2 bank charge screwed up the batteries and/or the charger?

[CatFan]

You should have been fine with one bank on each battery and leaving the parallel connection intact while charging.

What model charger do you use?  Some are not suitable for AGMs, but this is rare.

Parallel battery operation has a few "gotchas".  If one battery fails, it's usually going to take out the other one, either by draining it rapidly or by causing the charger to stay on and overcharge the other one.

From your description of the situation, I'd be double-checking the charger wiring.

[Creel Limit Zero]

You should have been fine with one bank on each battery and leaving the parallel connection intact while charging.

This is rolling the dice if you don't know if the charger has reverse polarity, if you are not sure, please do not hook up 2 batteries in parallel with 2 banks.  The reason is that the chargers will very likely complete one or more of their charging subroutines (charge modes or stages) at different times. That means that each charger would be trying to bring the battery pack to a different voltage level. Depending on how the chargers are configured to prevent a reverse polarity connection, the charger with the lower voltage output could possibly draw current from the charger with the higher voltage output, or even from the battery pack that it is trying to charge. If the chargers' reverse polarity protection mechanism includes a solid state, unidirectional, voltage controlled, current switch (like a diode), then this is not a big problem.

If you are not sure your charger has the reverse polarity connection between the banks, I would not use it with them connected.

If you are unsure, all you need to use two banks is get one quick connector.  You will lose very little voltage with this quick connect if you solder in the wires...

http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?_DARGS=/cabelas/en/common/catalog/item-link.jsp_A&_DAV=MainCatcat21276-cat21284-cat604551&id=0001110011811a&navCount=3&podId=0001110&parentId=&masterpathid=&navAction=push&catalogCode=IA&rid=&parentType=&indexId=cat604551&hasJS=true

[ystribling]

Thanks again for all the info.  I think the 2 banks going to the 2 parallel Optima trolling motors was too much for them.  The charger is a 10/10/10 Bass Pro Shop XPS charger.  That is all I could read.  I think the ability to break the parallel connection and charge like normal is the way I will go.
2 last questions....is there a way to determine if 1 or both of the batteries were damaged?  Same with the charger?
  And second, what can I use to break the parallel connection?  Gator clips or is there a better, I am guessing there is, way to break the parallel circuit?
Thank you again to all who have tried to help.  It is very appreciated.

[Creel Limit Zero]

http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?_DARGS=/cabelas/en/common/catalog/item-link.jsp_A&_DAV=MainCatcat21276-cat21284-cat604551&id=0001110011811a&navCount=3&podId=0001110&parentId=&masterpathid=&navAction=push&catalogCode=IA&rid=&parentType=&indexId=cat604551&hasJS=true

Click on this link, it is the connector I used to use when I had 2 batteries parallel and was charging them.  Be careful with charging the Optimas, you don't ever want to overcharge them.  At 10 Amps per bank, 6 hours should do it every time. 

As for the sulfur smell, that tends to happen when you overcharge them.  With Wet cell batteries, you can overcome most of the damage by just adding some distilled water, but you can't do that with sealed batteries.  You can get a meter and see how much is in each battery after charging them up, that's about the only way to see if they are still holding a full charge.  But those can be quite expensive.  You can just get one of those short handheld meters, to see if each of them have a full charge.  Then when you are out on the water next time, just check them every hour and see if they are losing their charge quickly. 

Are both batteries the same age or one newer than the other?  If they are both new and you see one battery losing its charge much quicker than the other one, you have a bad battery and I'd take it back for another.  I had that problem this Spring.  Two new batteries, every time I took it out, one battery had no juice left over, one was still okay.  I then checked it every hour the next time out.  Sure enough, one battery was at 6% left on the battery with less than 1 hour on the water.  Bad battery, replaced with new one... 

Good luck, let us know how it all turns out. 

[ystribling]

Thanks,
Dropped it off this morning and they are going to put a disconnect on the parallel jump line so I can break the connection when charging.  Seems like the best idea.  They will also check the batteries (both bought on the same day 2 years ago but probably only used 25 days)  and the charger.  The Charger is an XPS Bass Pro model that is apparently made by Mariner.  The people at the shop said it was very good charger and was "smart." So hopefully I didn't kill one or more batteries and will have things set up where it wont happen again.
Good news is that i am also having new electronics put on the boat for the first time in 13 years.
Thanks again for the help.