Two Battery Set-ups in Parallel

**fishervet** · 05-11-2016, 05:35 PM

Originally Posted by "G"

Depends on boat hull size and total boat weight with persons and gear etc......also depends on what trolling motor you have on mine full speed is about 3 mph....Two group 31 in series for 24 volts will run my 80 lb. Terrova 8 hrs. with power left at a continious 1.7-1.8 mph. This is with just a slight wind......If your trolling head on into much wind it will make a difference in your run time also.

i have a 17 ft grizzly tracker with a mg salt water version tm...modified v hull...the battery which i have now is 3 yrs old and i might...might get 3 hrs if the crank bait bite is on.....light wind.my option is to get 2 batts and run em parallel to get mo run time....depending on what you think about a single gr 31 single batt.. Thanks G.

**"G"** · 05-11-2016, 06:09 PM

Tal is your TM a 12 volt ? What lb. thrust is it ?

**fishervet** · 05-12-2016, 08:18 AM

Originally Posted by "G"

Tal is your TM a 12 volt ? What lb. thrust is it ?

12 volt and 55 # thrust....

**cevans** · 05-12-2016, 09:44 AM

For the past 7 ys, have switched to small tin boats and 12 volt trolling motors with batteries in parallel. I started out with the largest agm Sears expensive deep cycle (1100 amps) and then added their smaller agm (880 amps) and trolling motors are 55lb thrust min kota's and have never had a problem getting 8 to even 10 hrs of running time running them in parallel with trolling motor attached to the largest strongest amp battery. I know this is against the so called rules of hooking them parallel and not having identical batteries hooked in series, but never had a problem of running trolling motor or length of time running, as I primarily long line and crank and trolling motor is on continuously. When the batteries finally go dead, will spend the money to get 2 that match for the trolling motor usage. I do have and run a third battery for gas motor and all other items in boat hooked to it. Comment why I see no decrease in power over 8-10 hrs or would I see a vast improvement if I upgraded to 2 uniform batteries now. I am now running a new min Kota v2 12v with co pilot and see no need to change my setup.

**Cray** · 05-12-2016, 10:54 AM

Originally Posted by cevans

For the past 7 ys, have switched to small tin boats and 12 volt trolling motors with batteries in parallel. I started out with the largest agm Sears expensive deep cycle (1100 amps) and then added their smaller agm (880 amps) and trolling motors are 55lb thrust min kota's and have never had a problem getting 8 to even 10 hrs of running time running them in parallel with trolling motor attached to the largest strongest amp battery. I know this is against the so called rules of hooking them parallel and not having identical batteries hooked in series, but never had a problem of running trolling motor or length of time running, as I primarily long line and crank and trolling motor is on continuously. When the batteries finally go dead, will spend the money to get 2 that match for the trolling motor usage. I do have and run a third battery for gas motor and all other items in boat hooked to it. Comment why I see no decrease in power over 8-10 hrs or would I see a vast improvement if I upgraded to 2 uniform batteries now. I am now running a new min Kota v2 12v with co pilot and see no need to change my setup.

Main reason is that your smaller battery is going to deplete first, then it will pull juice from stronger battery trying to equalize. Thus drawing down larger battery. Yes it works and has not given you problems but the ideal thing is running 2 that are same capacity. When buying new the dollar difference isn't that much.

**Cray** · 05-12-2016, 11:08 AM

Originally Posted by fishervet

i have a 17 ft grizzly tracker with a mg salt water version tm...modified v hull...the battery which i have now is 3 yrs old and i might...might get 3 hrs if the crank bait bite is on.....light wind.my option is to get 2 batts and run em parallel to get mo run time....depending on what you think about a single gr 31 single batt.. Thanks G.

Tal, I run a 55 Terrova on a 17 ft Wareagle with 2 group 27 batteries. I can get a good 4 hr's if not breezy pulling cranks. If you are going to keep that motor and try to pull cranks and you have the room bite the bullet and get at least 1 golf cart battery. Way more reserve capacity than even a group 31. And not a whole lot more dollars.

**cevans** · 05-12-2016, 11:14 AM

Originally Posted by cray

Main reason is that your smaller battery is going to deplete first, then it will pull juice from stronger battery trying to equalize. Thus drawing down larger battery. Yes it works and has not given you problems but the ideal thing is running 2 that are same capacity. When buying new the dollar difference isn't that much.

Will the v2 min Kota run faster and stronger with a two identical battery in parallel setup vs what I have now? I have been waiting in these Sears batteries to die and now in 6th year of running heck out of them.

**cevans** · 05-12-2016, 11:17 AM

Originally Posted by cray

Tal, I run a 55 Terrova on a 17 ft Wareagle with 2 group 27 batteries. I can get a good 4 hr's if not breezy pulling cranks. If you are going to keep that motor and try to pull cranks and you have the room bite the bullet and get at least 1 golf cart battery. Way more reserve capacity than even a group 31. And not a whole lot more dollars.

Do golf cart batteries come in diff. sizes? And best place to buy?

**fishervet** · 05-12-2016, 11:48 AM

Originally Posted by cevans

Do golf cart batteries come in diff. sizes? And best place to buy?

**SeaRay** · 05-12-2016, 12:19 PM

They come in various sizes and voltages, like 6,8, and 12 volt. I bought 2 six volt Interstates hooked in series for 12 volts to for our motor home. This was on the advice of an Interstate rep at an RV show.
Reason for the 6 volts were that battery had a tremendous reserve amp capacity.
The difference was remarkable over the 2 12 volt deep cycle Interstates we had before.
We had a ceiling fan plus all the other stuff running off the batteries when we were parked without A/V hookups.
The percentage of use was about half what the previous ones were after 24 hours of running.
They were big boys though. I had to put an extension on the hold down brackets because these were about 2" taller than the 12 volt ones. Same length and width, just taller. Nice things was there was very little difference in price. If you are near a large RV dealer, go check them out at their store. This is everyday stuff for them.

Thread: Two Battery Set-ups in Parallel

Thread Tools

Display

Tags for this Thread

Posting Permissions