Pontoon Boat & Deck Boat Forum

This question is directed at those of you with 24v trolling motors. Currently, I have one battery in the back that runs everything. I am wanting to add some docking lights and under-decking led lights for some night fishing/bow fishing this fall. I plan on having a 24v trolling motor installed this spring, but I would like to add a battery this fall so I can run the lights. How do you guys have your batteries set up with 24v install? 2 in front; one in back? 3 in back? 2 in back? Can you get the alternator on the motor to charge batteries on the front? Thanks!

I have 4 batteries total. Start battery and house battery combined with voltage sensor system. Then 2 more in back in series for 24 volt trolling motor. Don't charge trolling motor with engine electrics, I charge them with a 3 bank charger once I put boat back in slip. Installed a built in plug to the 3 bank charger so when I pull in I just plug a cord into the side of sun deck plug.
Can furnish more details if you need it.

Regards,
Tully

I would say that while having all your batteries in one location for service is the way to go but you will need to take into consideration weight distribution as well as space requirements on your boat as battery weight can add up quickly.

If your going to install a 24 volt system you will not be able to charge that from your engines 12 volt system anyway; that will have to be charged by a 24 volt charger.

While a second "house" or aux battery can be added into an existing system you should have a proper battery isolation switch which allows you to select battery 1 or 2 or both. This helps prevent you from unknowingly killing both your batteries.

Another thought to keep in mind is on a 24 volt battery bank it is NOT a good idea at all to "tap" any 12 volt items such as lights or radio onto any one battery as this creates unequal power use and worse yet unequal charging whereas the battery with less use must receive charge until the battery with more use catches up. This will shorten battery life....

Thanks for the great advice. I think I'll add a second "house" battery to run the new lights and stereo. I've been wanting to do that for a while now.

I'll probably add a 24 v system and keep the two batteries up front. Although, 4 batteries seems like a lot on a 20ft boat. Maybe I should just get the biggest 12v motor. Luckily I have some time to make that decision.

Heres one way.

You tap 12 volt off both batteries at the same time to keep them EQ'ed up , but but a fuse on it, you have a lot of amps and good to use on a long week end trips

Another option to keep in mind is if you really want to be able to draw 12 volts off of a 24 volt battery bank is to purchase a "quality" power reducer to step the 24 volts down to 12 volts.... We have a set of batteries on board ship set up for 24 volts to run some of our larger pieces of electronic gear that was also tapped for 12 volts to run the likes of VHF radios and such; this installation has been a PITA since day one as we have to check water much more frequently and the batteries usually fail somewhere between 2 and 3 years whereas we get a full 4 years and better on all other lead acid battery installs.

C_M_25 wrote:Thanks for the great advice. I think I'll add a second "house" battery to run the new lights and stereo. I've been wanting to do that for a while now.

I'll probably add a 24 v system and keep the two batteries up front. Although, 4 batteries seems like a lot on a 20ft boat. Maybe I should just get the biggest 12v motor. Luckily I have some time to make that decision.

My two cents...

Lots of great advice already given in previous posts...

We have a 21' fishin' barge with a 55lb. Thrust, 52" shaft minn kota trolling motor made for pontoon boats... as far as I know it's the largest most powerful 12v trolling motor... it is more than enough for our boat...

We installed a minn kota mk -1-dc onboard alternator charger... super easy to install... charges our trolling motor battery when the motor is running... yet the two batteries are seperate... so, if we run the trolling motor battery dead.... our engine battery is not.... when we run the engine... the alternator charges both... we never have to mess with charging! Love it... works great... plus it increases the "up" time for our trolling battery... as we move from spot to spot with the engine our trolling battery is getting charged back up!

You can get them for up to three battery setups and they will charge 12, 24 or 36 volt systems... if you decide to run seperate house and trolling motor batteries it will still work.