Battery locations?

[lakeorbay]

Please point me in the right direction if this Q is in the wrong forum.

I've been thinking (day dreaming) of what I plan on using my boat for and thought of how many and how my batteries should be laid out.

I know I'll need a cranking battery in the back by the motor.

I plan on having a 100lb+ thrust trolling motor. I haven't decided on 24v or 36v yet. 24hr over night bass fishing and all day trolling (using the trolling motor) trips I foresee in my future. So, that's going to be 2-3 batteries up front.

I will have plenty of accessories that will need power, so I was thinking of placing a battery somewhere in the middle strictly for that purpose. I was thinking under one of my consoles.

This raises some Q's

Where can I find a good source wiring diagram for my type situation?

Is my plan too extreme, unnecessary, unorthodox? I don't know, I have nothing to go on.

What would be the best way to apply on-board chargers to a situation like that?

Should I skip the accessory battery and just feed off the trolling motor battery or engine battery?

 

[drewpster]

Re: Battery locations?

Your only real limitation is the room you have to mount the batteries you want to use. I would avoid mounting all of them on one side because it could cause list. It would be ideal to mount them along the centerline of the keel. But that is not always an option.
I am sure there is some complicated mathmatical formula to figure out exactely how many batteries you need for the time you need them. (just to have them go dead anyway) But I do not know the formula and I am not good with math.
I think it is perfectely reasonable to have four batteries for what you want to do. At least two batteries for starting and house loads is a very good idea. Use one all the time and a second for backup. Given the thrust of your trolling motor you will need the capacity to keep it going as well.
If you do go with four, I recommend two seperate automatic on board chargers. One mounted forward, one aft. Get the hightest amp rated auto chargers you can afford with two banks each. Getting everything mounted without riding sideways is going to be the trick.
The best place for advice on wiring all of it is in the Electrics forum. Battery questions come up often and there is some smart people over there.
drewp

 

[Woodnaut]

Re: Battery locations?

I have two batteries located all the way up in the bow. The battery select/disconnect switch is also up there. You can just barely see it in this photo under and past the helm. I ran some 2 AWG marine grade wire aft to the outboard (F90 Hp Yamaha). Helped with the trim of the boat since the outboard is a bit heavy (four stroke). Plenty of power with that size of wire.

 

[lakeorbay]

Re: Battery locations?

Excellent input guys, thanks. I have some opinions now, that helps and I'll check with the electronics forum.

 

[TojosMojo]

Re: Battery locations?

After having several bass boats and seeing the setup on hundreds of fishing rigs at boat shows, tournaments and etc over the years, the proper placement for a three battery system (1 cranking and two trolling set up for 24volts) would be about a 12-18 inches from the stern of the boat placed as follows:

Cranking battery on the drivers side and the two deep cycle trolling batteries set "side by side" on the opposite side, and placed about 12 inches from the center line of the boat. This setup is optimum for even weight distribution when you are by yourself. When passengers are with you you can off set the weight by placing your gear ether port or starboard for a better distribution of weight.

Deep V boats "properly powered" ride on their last 1/3 of their hull (Pad) and need to have a weight distribution that places as much weight rearward as possible to maintain a stable ride like fuel, batteries, cooler, extra fishing gear etc. Too much weight say an extra 60-70 pound battery up front in the bow or console area along with a full livewell can cause smaller lighter boats to pitch forward and fall off the pad which in turn the boat will be constantly fighting to keep the bow up.

If you go with a 100 pound thrust trolling motor you will need the 36 volt system if you plan on using the boat on a multiple day fishing trip without an overnight charge (still depends on the wind and current you are fighting that day). My smaller 55 pound thrust 24 volt could go two full days without a charge, but my 101 minnkota needed that third battery to do the same job. Your also going to want to get deep cycles with the highest amp hours you can afford for that trolling motor.

 

[Silvertip]

Re: Battery locations?

On all-night fishing excursions you are going to run short of battery power no matter what you do. That assumes of course that the troller sees about a 50% duty cycle. Lights, radio, live well pumps, bilge pumps, aerators, spotlights, nav/anchor lights, all draw power. The Tojos system just described would be an absolute minimum. For chargers you need a three bank minimum just for the 36 volt troller batteries and just like the batteries, bigger (capacity) is better. You can use a smaller, single bank charger for the starting battery if you feel that's necessary. You didn't tell us how big the boat is or what type it is so space may be another restriction on what you can achieve. Size of the boat also determines how big the troller needs to be. If you can get by with a 24 volt motor, then adding one more deep cycle would virtually guarantee you would have enough power for long run times. This would allow two 24 volt banks selected using a dual battery switch to keep them isolated. A dual bank on-board charger could be used by bridging the outputs, connecting to the switch which would then allow charging each bank individually or simulanteously.

 

[lakeorbay]

Re: Battery locations?

When it comes to trolling motors, I guess bigger is not always better. (I might need to start a trolling motor thread now).

I should have given more details. I have 17' Lund Tyee. I guess that qualifies as a deep V. It's a multi-species, but I plan to do a lot of bass fishing with it. It's not powered now, but I plan on having a Evinrude E-Tech 115hp or maybe 130hp if I can get coast guard approval (that's another story). It's rated up to 125hp. Ain't that a b!tch? Missed it by 5hp.

I don't necessarily HAVE TO have 100lb+ trolling motor, I just don't want to go too weak. I would prefer 24v anyway (one less battery, less money and weight). My boat has high sides that would probably catch wind and I do a lot of fishing against wind blown points. To be wrong about voltage and pounds thrust, would be expensive trial and error.

-Is 24v enough?

-Is 80lb thrust enough?

-If had only a 3 batteries system, which battery do I run accessories off of? (Accessories would include: nav lights, black light system, intermittent spot light, radio, 2 fishfinders, and maybe a couple other toys I haven't though of.)

-So, it sounds like trolling motor batteries are stored in back (stern) and then run cables to the bow. Correct?

Thanks to you all.

 

[Silvertip]

Re: Battery locations?

The way you describe your situation, if you have a 36 volt system for the troller and actually need that much power, then the other accessories should not be run off any of the trolling batteries, except possibly the bow mounted locator. On a 24 volt single bank system I would add a third deep cycle for the accessories and install a dual battery switch, ACR, or isolator so the engine can help keep that battery and the start battery topped off. Leave the troller batteries for troller and locator use. For 12 volt accessories that you do decide to run from the troller bank, use the battery that has the troller ground cable connected to it. This eliminates any possibility of an inadvertent ground to that battery which would fry 12 volt electronics if you connected that accessory POS cable to the first battery in the string (the one with the troller POS cable connected to it.)

You really need to talk to a Lund dealer and explain the situation. Just make sure you talk to someone that actually knows what they are talking about. Many sales persons are not fisherman and have no idea how much power you need for a given boat. But rest assured that same person would tell you need at least three 100# trollers (just to be safe don't ya' know!)

 

[Bass Man Bruce]

Re: Battery locations?

Lakeorbay, I have a 17' deep vee (aluminum) Sea Nymph with a 24volt 65# thrust Minkota powerdrive and it has plenty of power. I run two deep cycles on the troller, one on the {outboard (Etec 50 hp), nav lights, bilge, livewell} and then what I call ice fishing batts on the stereo and sonar. (small, like a motor cycle batt. saves money and weight) they work great, sonar is lowrance X-85.