two 12 volts batteries for 12v troll motor

[gonefishie]

Hey guys! this topic probably came up before but I haven't seen it. I'm tired of running out of power especially on a windy day which seem like everytime I'm on the water these days. I want to go to 2 batteries for my 12v trolling motor. Should I connect the batteries in parallel and connect the wires to either one of the battery? In theory, this should stay at 12v and double up on the amp hour right? Have anyone done this? Thanks in advance.

 

[Dunaruna]

Re: two 12 volts batteries for 12v troll motor

Your 'theory' is spot on. Connect in parallel and double your amp hrs. The batts must be the same though. Deep cycle work best for electric kickers.<br /><br />Aldo

 

[Drowned Rat]

Re: two 12 volts batteries for 12v troll motor

gf, you will actually increase your run time by up to 200% by doing that because the draw on each battery will be reduced. Make sure to hook pos to pos and neg to neg on the batteries. When you hook up your troller, hook the neg wire to one battery and pos wire to the other battery so it pulls equally of each one. Good luck.

 

[Boatist]

Re: two 12 volts batteries for 12v troll motor

You can do it that way but batteries must be same type and same age. Still even then if one battery fails both will fail. A dead cell in one battery will destroy the good battery.<br /><br />If your motor can be wired for 24 volts then wire in series.<br /><br />Way I perfer for a 12 volt motor is to install thru a battery switch. Run on battery 1 until first shows signs of weak battery then switch to battery 2. This way batteries do not have to be same type or size or age and one battery can not destroy the other. If you use a 1, 2, both switch then to run in both postion the battery again must be same type, size, and condition.

 

[gonefishie]

Re: two 12 volts batteries for 12v troll motor

I can get the same battery but would have the age problem. The one I have now is only a year old, does that make a big different? I don't know if the Minkota All Terrain can be wired for 24v or not.

 

[Boatist]

Re: two 12 volts batteries for 12v troll motor

GoneFishie<br />In my opinion different age batteries is a problem. As an example lets say your one year old battery at full charge has a voltage of 12.4 volts. Now you new battery has a voltage of 12.7 volts. As soon as you hook them up in parallel the 12.7 volt battery will try and charge the 12.4 volt battery but what really happends is the 12.4 vlot batteries drains the 12.7 volt battery down to 12.4 volts. No battery will be better than the weakest battery. I belive both batteries die sooner connected in parallel unless you use isolation diodes. Some will likely disagree.

 

[waterone1@aol.com]

Re: two 12 volts batteries for 12v troll motor

I would test the battery(the existing one) with a hydrometer and make sure it is attaining full charge. If so, I would connect both in parallel (+ to + and - to -). There is nothing wrong with the diode setup, but it will drop .5 volts on each battery and complicate the system. I would not try this(without diodes) with 1 new and a 3 year old battery though.

 

[LubeDude]

Re: two 12 volts batteries for 12v troll motor

I run my batteries as you are describing, and Its imperative that you have two new Identical batteries to start with. When hooking up your charger I would wire it as WetRat, (Sorry Drowned Rat) stated. Some say it makes no difference, but I think it equals out the batteries better myself. I wouldnt go through a swich, you will have better battery life discharging them together IMHO.

 

[jtexas]

Re: two 12 volts batteries for 12v troll motor

In this scenario, would 10gauge wire suffice for the batt-to-batt connection?

 

[Boatist]

Re: two 12 volts batteries for 12v troll motor

I would use the same size wire you have running to your trolling motor. The wire between batteries will only carry about half the current going to the motor and also will be short but will not cost that much more to use the same size.<br /><br />If the wire to your motor is 8 guage then wire between your batteries should have at least 10 guage.

 

[Boatist]

Re: two 12 volts batteries for 12v troll motor

You can charge both batteries at the same time and I would suggest at least a 15 amp automatic charger if your expect to charge in less than 24 hours.

 

[Silvertip]

Re: two 12 volts batteries for 12v troll motor

If the trolling motor requires 8 ga wire, then battery to battery wiring should also be 8 ga or larger. While its true each battery is delivering half the load, a bad connection on the forward battery means the entire load is suddenly from the back battery and you will now run the risk of smoking that 10 ga wire. Never use smaller wire in any circuit than the maximum current flow requires.

 

[jtexas]

Re: two 12 volts batteries for 12v troll motor

Excellent, mine takes 10 so 10 it is. You'd separate them for charging though, wouldn't you?<br /><br />thanks!<br />jtw<br /><br /><br />[p.s. thanks for the idea gonefishie I believe I'm gonna run with it!]

 

[Silvertip]

Re: two 12 volts batteries for 12v troll motor

For charging, there is no need to separate batteries wired in parallel. Keep in mind it will take twice as long to charge them as it would a single battery.

 

[LazyJ]

Re: two 12 volts batteries for 12v troll motor

Industrial standards for 6 & 8V battery connections is 6g, I'm thinking 12v is 4g no matter how insignificant the expected load. The reasoning being they will be sufficient to handle the crossflow should you lose 1 cell.<br /><br />And what happens when that 10 guage wire gets corroded and the smaller lug/crimp gets weak and breaks off sending the wire dancing towards the opposite polarity while you running across the lake. I've seen 2 batteries party with each other, spend the $10 on real cables.

 

[LubeDude]

Re: two 12 volts batteries for 12v troll motor

Originally posted by jtexas:<br /> In this scenario, would 10gauge wire suffice for the batt-to-batt connection?

They key word is "sufficient" (SP), I use two regular Battery cables, one red, one black, about 10" long, Then there are no worries, Only about $4.00 apiece. When I charge, I hook positive to one battery and negative to the other. I seem to think it works better, but there is no logical explination for it, it really shouldnt make any difference.

 

[gonefishie]

Re: two 12 volts batteries for 12v troll motor

I went to get another battery today and brought the one in the boat with me to get it check out make sure there are no bad cell or anything. Sure enough, it not 100 percent so Autozone took it back and gave me a brand new one since the old one is under warranty. Now I have 2 brand new identical batteries. For those who thinking of this setup, get your battery check out where you get it from and maybe you will get a new one and don't have to worry about not having 2 batteries with different age.