Trolling motor battery life

[AK]

I want to hook two trolling motor batteries (deep cycle) in parallel to extend my running time. Does anyone know if this will work?

[Team_Dougherty]

Yes it will work. It works the best if both batteries are the same AH rating.

[AK]

Thanks for confirming and mentioning the tip on the AH rating....hadn't considered that. Happy catching!

[surfer]

Yes it will work and the two batteries don't need to be the same amp hour for parallel.  They should be the same amp hour and age to connect them in series.

[Garnet]

I always found it better to drain 1 battery then hook up the second.

This will permenantly damage your batterys if you constantly do this.

But you will have more battery each day.

Garnet

[jim payne]

Curious as to why you would think doing this will damage your batteries??

[Team_Dougherty]

Yes it will work and the two batteries don't need to be the same amp hour for parallel.  They should be the same amp hour and age to connect them in series.

I would be careful using different AH batteries in parallel. the smaller AH battery can be over discharged before you know it. Even though the bigger AH battery will provide most of the amperage, when the smaller one is discharged,  current will still come from the smaller battery.

If you have two different AH batteries in series the total capacity is that of the smaller battery. When it is discharged the device that is being powerd will most likely stop working from low voltage. There is little chance of over discharge from the smaller AH battery.

Ideally when you are grouping batteries, series or parallel, they need to be the same AH rating. I would go as far as saying they should be the same type. AGM, wet cell etc...

[surfer]

I stand corrected.  Mismatched Ah will deplete the smaller battery and cause sulfation.  Thereby shortening its life.

However if you have a bunch of junk batteries that you aren't using anyways, then by all means you will get more time on the water by connecting them all together.