Big Motor to Trolling Motor Batteries

Has anyone wired their starting cables for the big motor off the last battery in line of the 36 volt trolling motor batteries.

I have had to jump start the big motor before by moving the starting cables over to the last battery in line for the trolling motor batteries. (the battery where the main trolling motor wiring goes up front to the trolling motor) By putting the positive cable on the + and the negative on the - you still are only getting power from that one 12 volt battery.

I've had it configured this way for over a month and through several tournaments. I use the starting battery to run electronics and livewell pumps only.

Has anyone else set-up their batteries this way? I haven't run out of trolling motor battery power yet with it wired this way.

had mine wired that way for a while until i fished a rockpile one day for 4 hrs in high wind. went to move to another spot and the motor barely would turn over. it will work but if you have room for a dedicated starting battery i think thats the best route to take. especially if you need to run livewells. i didnt because i dont fish tournies. my problem was my boat has very little space in the bilge area so in order to get 4 batteries and powerpole pumps back there i had to stack the oil tank on top of the starting battery. so far so good!

Bad idea. The additional load on that one battery will reduce the life of all 3.

I've only done that when my cranking battery died once. Just try to get 4 back there and if you can make it fit get a big cranking battery. I use a 29 series everstart for cranking and electronics from Wal-Mart. they have a 2 year free replacement.

This is what I see happening.

A cheap set of jumper cables is a great solution. No moving battery wires.

I see you already have four. I personally wouldn't keep doing that. look into upgrading your cranking battery

Upgrade the cranking battery

I re-read the original post, are you saying that you left the wiring this way just because you haven't gotten around to re-wiring it?

How do you charge the 4th battery if it isn't connected to the motor? Livewells and electronics are what make a cranking battery go dead, not cranking the motor.

Coolest thing I have seen in a while....

My buddy has a set up that tends the batteries, not uncommon, but the cool thing is that when you go to crank it opens the switch to another batter for more starting amps. but when your just running electronics it only runs of one. thing is great...

There seems to be a trend with all of the electronics connected to the cranking battery(power poles, hydrowave, depth finders, etc.) that they will run down on occasion. I had this issue when I run my live wells all day when fishing a tournament. I have changed to the largest cranking battery I can find and mine will still run down on occasion especially if I am not moving around very much. I carry jumper cables but have found that trying to jump off of the trolling batteries doesn't always work. What I have found that works is one of the portable jump starters. They are easy to hook up and I have not been stranded since I have started carrying this on every trip. Not only have I used it but I have been able to help out others that had dead cranking batteries as well. Its a little more weight to carry but the peace of mind it gives me is worth it.

So far it's worked great. I haven't run the trolling motor batteries down even fishing 8 or 9 hours in a tournament. The big motor (yamaha 250) starts everytime with no sluggishness.

My electronics and livewells run all day without running out of juice.

I don't know; it's working fine.

I agree with a couple of guys here, jumper cables don't always work, been there done that; moving the motor cables has always gotten it started though.

It will work fine but it will cost you money in the long run. Unbalanced load on a bank of batteries in series is not desirable

Besides that, something caused your cranking battery to die once, and it wasn't cranking your motor.

yeah, forgetting to charge it once. The there is no unbalanced load on the batteries because the only draw is from the battery the motor is hooked up to. Once the motor starts it begins putting the power back to the battery.

You'll have to prove to me how it's detrimental other than just saying it's not.

Yes, I agree that the "unbalanced" issue is incorrect, that actually batteries in a series offer advantages that, at first, seems counter-intuitive. But, we are all, me too, inductive thinkers so we have experiences, just life anecdotes and no science behind it, and we later try to fit new information into our own "thinking."

You buy XXXX braid and for some reason it breaks off at a lure on your first cast? Most of us are done with it, forever, as if we have run a scientific study.

Most people understand that two 12V batteries don't give you 24 volts. An analogy? If you have two guys who get behind a car and they can, each one by themselves, push the car 10 MPH but their top end is also limited to 10 MPH, then two guys pushing a car can't push it 20 mph. They just are unable to move that fast. Batteries are like this.

What they can do is push the car at the 10 MPH for a longer period of time. Twice as long? No, not with batteries: it is actually much more.

Here is a great video by a battery expert dude explaining that with batteries, 1 + 1 is greater than 2. Worth looking at his vids to understand batteries better. It has to do with residual charge availability, getting more power out of batteries in a series.

https://www.youtube.com/watch?v=snaJxB_psg8

Back to your situation: The only issue I can see is if for some reason when you use deep cycle batteries for cranking a hungry motor, that they lack the punch it takes. Deep cycle batteries are low on cranking power, high on long draining charges and having a series of them still can't pass through the power one might need.

But, batteries have a top end that usually greatly exceeds the cranking power to start a motor, especially a fresh battery, and you seem to be pulling enough power to get the motor started, so what's not to like?

I'd still replace the cranking battery especially if it has degraded with age or perhaps by letting it sit de-charged for too long.

Brad

I have a perco jump start switch and all my batteries are in there normal positions no need to move cables or jumper cables.

Thanks for the illustration. Very informative.

I won't go into the physics of batteries here, but a quick Google search will show you that it is not recommended.

http://www.allaboutcircuits.com/vol_1/chpt_11/5.html

Any time you remove energy from a battery or even recharge a battery the physical properties of said battery are altered slightly, changing the AH rating and max voltage of the battery.

I used to keep and extra battery with just my motor attached. No need to charge it and the accessories worked off another battery. One thing I found out was that my Tach quit working. I found that you need to connect the acc. batteries neg - post to the cranking battery neg - post. That solved the Tach problem. If I ever ran down the acc battery it only took 1 cable to jump over to the cranking for some more power.

Jody

A better solution would be to get a 36 to 12v down converter and run your electronics off of it. Leave the starting battery for starting the motor.
I recently did this on mine, I have a 24v TM so I used a 24v to 12v converter. Since the 12v side of the converter is regulated and filtered the power going to the electronics if very clean. The load on the TM batteries is minimal since the load is spread over both of them.

I've been thinking of adding one of these to the boat.
http://www.amazon.com/NOCO-GB30-UltraSafe-Lithium-Starter/dp/B00M1OUBES