Battery Charging Question???

[elnutsmalljaws]

I have a 12 volt Minn Kota trolling motor (Yes I should have gotten a 24v, but too late now). I built a platform under my front deck to hold 2 batteries a couple of years ago for I was always running 1 down, especially during my 10-14 hour night fishing excursions. I was told that I can run these batteries in series, + to + and - to -, and will still get 12v to the trolling motor which will eliminate the step of changing over the leads from the dead battery to the charged battery. I just installed a 2 bank 10amp on board charger that I have hooked up to each battery. My question is can I leave the on board charger hooked to both batteries plus have both batteries hooked in series and have the trolling motor leads installed as well when I plug in the charger? Or do I have to take off the wires that are connecting the 2 batteries in series every time I want to charge my batteries? I don't want to damage the batteries or trolling motor during the charging process. Looking for somebody smarter than me for the answer please.

Tight Lines

[DJD]

[font size="1" color="#FF0000"]LAST EDITED ON Mar-08-06 AT 05:39PM (EST)[/font][p]**(helpful hint)** By putting + to + and - to - you are placing the batteries in parallel not series, which is what you want of course. Series would not be correct because you would end up with 24vdc. In parallel you will gain the amp hours of two batteries while keeping your voltage at 12vdc.
I have not installed an onboard charger so i don't know on your main question, sorry. Contact Minn Kota if you have time. Good Luck.

[bkehl]

elnuts;
You should only need to hook up 1 bank to 1 Battery, the second Battery will be will be charged at the same time as the first Battery, example when you are using the Trolling Motor with the to Batteries hooked up the way you have them, you will be discharging each battery at the same rate, therefore the recharging works the same, If your boat has an Electric Start on the Gas Motor and you use a 3rd battery for it, just hook the 2nd bank of the charger to that battery. If you do not have a 3rd battey, remove the connecting terminals and tape them up to avoid any possiblity of shorting out Having the Charger hooked up at the same time that the Trolling Motor is hooked will damaged the Trolling Motor. 12 volts is 12 volts no matter ware it comes from. Just make sure that you only hook positive to positive, if 24 volts get to the Trolling Motor it good by Trolling Motor.

Hope this is helpful
BKehl

[sparkie_212]

"I just installed a 2 bank 10amp on board charger that I have hooked up to each battery."

Don't leave both sets of leads hooked up from the charger to the batteries, you may fry the new charger. 2 bank simply means for 2 batteries. Your parallel installation of the batteries is like having 1 battery only twice as powerful. Everything bk said is correct. Check instructions for single bank install. They may want you to use one set opposed to the other, but should not matter. So in other words, only hook up one set of charging leads from charger.

[Fishwright]

While charging your batteries, make SURE you disconnect your trolling motor. I have a Minn Kota Power Drive, I burned up the circuit board in it while charging the batteries. I was told that what caused it anyway. I bought a battery disconnect switch and always turn my batteries off while charging them now and have not had any more problems.

[firekracker50]

Yeah about everything they have told you is correct, running them in parrallel is what you want to do and you do want to hook up the charger to only one of the parralleled bateries... parralleling will increase the charge time b/c you have increased you AH. If you have a 2-bank charger that has on-demand power shifting take advantage of it. You can hook 1 bank of the 2 bank charger to one of the parralleled batteries and the other bank to your cranking battery. If the cranking battery doesn't need to charging it will divert more power to the trolling batteries and charge them quicker. For instance if it is a 10/10 2 bank charger and the cranking battery is almost charged, after the charger has warmed up the batteries, the charge will start to fade from one bank to the other, possibly 2amps to the almost charged battery and devote 18amps to charging the trolling batteries. Thus giving you much quicker charge times.

[firekracker50]

Also you definately want to make sure you have a trolling motor w/ a plug, or a power switch. Either way just make sure that the charger can't reach the trolling motor, because if you do you can say bye bye to the circuit boards on any of the new trolling motors and possibly fry older ones too. They are not designed to qwithstand those high amp levels/ voltages for that matter.