series, parallel or what?

[fishnfool]

Dumd question, but can I hook 2 batteries together to run my trolling motor? It is a 12 volt. Will the charge last twice as long ? I assume it will have the same amount of power. I also have an onboard charger, if I hook it up to both batteries will it charge properly? Would I be better off to get a switch and run one till it's low then change over to the other? Parallel - pos. to pos.to motor , neg.to neg.to motor ???
How heavy of wire between the 2 ? Gettin spring fever and hookin it up tomarrow. Lot's of questions any ideas? thanks

[perchjerker]

Yes, you can hook the batteries in parallel for 12 volts.

Depends on the charger for that hookup. Can be done. I would check with the manufacturers website.
We had a lively discussion about trolling motor wiring on the boat/motor link. Look for tips on trolling motor installation for all the fun we had.

Heres the link:

http://www.walleyecentral.com/cgi-bin/dcf/dcboard.cgi?az=show_thread&om=10166&forum=boatsandmotors&omm=0

[fishnfool]

There was nothing on the manufacturers site. Witch way would be better? Have read that thread.

[rickn]

yes, parallel is plus to plus, thats the way to keep 12 volts to your motor. If your on board charger has more than one bank, hook one to the troller bat, and maybe one to your cranking bat. Otherwise, the red leads can be hooked on the same post, but it won't charge any quicker. I don't think it matters for run time if you use one first then the other, but if hooked parellel, you won't have to hook up one, then change batteries on the water.

[Esox46]

Yes, two 12v batteries hooked in parallel will still be 12v and should give you twice the running time.

Now for the on-board charger hook up...I faced this problem last spring when I bought a charger for my 12v parallel set up. You can hook up each bank to each battery but with some chargers, their electronics think it is one BIG 12V battery! And will only charge one side or battery, cutting off power to the other. My Guest #2620 (2 x 10a) did this. To solve the problem, simply unhook one side (either pos or neg) of one of the parallel jumpers that strap the two batteries together. This breaks the parallel circuit and the charger will then charge both batteries simultaneously. Remember to rehook the jumper after charging is complete or your motor will still run at full thrust but only off one battery.

There is very little written about parallel systems and onboard hook ups! I sought advice from many, many sources until the above was told to me. But it seems to work fine now.

Good luck
Tony

[MK]

#10 stranded copper should be sufficient for connecting the 2 batteries together for a trolling motor. Most trolling motor plug-in recpticles on the boat come with #10 wire size going to the batteries. You might go bigger (#8) if you want but there shouldn't be any need for any larger. I used #10 on mine and have no problems. Use good connectors and solder them if you can.

I wouldn't switch them and run off of only one and then the other. It wouldn't physically hurt them, but depending on your charger setup, it might work better charging two batteries that have the same level of charge. See the other posts concerning charging. And yes, pos. to pos./ neg.to neg. for parallel connection.

[Jim Carroll]

Charging multiple jumped batteries is specific to the charger. One of the many things I like about Dual Pro chargers is that you do not have to remove the jumpers...

Snip from http://www.dualpro.com/FAQS.htm

2. I have a 24 volt trolling motor and my two deep cycle trolling batteries are wired in series. Do I have to remove the jumper wire between the batteries when I charge the batteries with my Dual Pro Charger?

No, there is no need to remove the series jumper because the Dual Pro consists of two totally independent chargers which share nothing in common. This allows for both batteries to independently but simultaneously charged.

[Esox46]

Jim,

You are correct and Dual Pro chargers and 24v series systems are great. Wish I had one.

However, I believe the gentleman is asking about 12v parallel systems and with SOME chargers you have to unfortunately remove a jumper to break the parallel circuit in order to charge both batteries simultaneouly. If there is a better way to do it, I would sure like to know too.

Tony

[Jim Carroll]

Esox- You are correct. I missed "parallel" in the original post. Sorry if I've caused any confusion....

[Planocat]

Use a Perko cutoff switch on your jumper cable. Much easier. I turn mine off when I plug in the charger, back on when I disconnect the extension cord.

[fishnfool]

Wow! What a great place to get help! Everything I needed to know! Looks like I will have unhook the jumper when charging but sounds way better than a dead battery. My charger is an 8 amp and not a very spendy one. THANKS for the replies !!!!!