Batteries

If you split up a matched set of batteries and use one on a trolling motor you no longer have a nice matched set of batteries. Putting batteries in parallel is undesirable anyway since they don't always charge and discharge exactly the same. Using 1 for another purpose will only make it that much work. I'd use 2 6 volts. If you want to take them BOTH out and use on your trolling motor then have at it.

Make sure they are true "deep discharge" batteries. Typical marine batteries are dual purpose and therefore are a compromise.

Trojan Reliant T1275-AGM

You will need to have a good charger/converter for those new batteries too, AGM or flooded wet cells. Along with that you may need to upgrade the battery wiring to accommodate the higher charge amperage. More on that later as you decide what to do.

Jim

Costco batteries.

Having two 6v GC2 in different locations may complicate the wiring a bit.
Having two 12v in different locations may cause unbalanced charging over time.

I recommend Lifeline deep cycle AGM.

I would go with the 2 12V batteries as it gives you more options.

When we camp at the ski hill we don't need the genny if it's only 1 night on 2 AGM 12v batteries. For the second night we need to add some charge to the batteries with the genny.

theoldwizard1 wrote:
Make sure they are true "deep discharge" batteries. Typical marine batteries are dual purpose and therefore are a compromise.

Trojan Reliant T1275-AGM

Huge +1 for the Trojan batteries. They are made for different purposes than the consumer targeted batteries. Things like floor buffers, golf carts, etc. My first one (purchased a decade ago) is still 'good', but I like my batteries to be 'great', so I replaced it this year.

Mine: Trojan T-1275

Spend the money, water the battery annually, and you won't be disappointed.

-Eric

youngm357 wrote:
Costco batteries.

I assume you mean to Costco 6V GC2 batteries. Great "bang for the buck" !

time2roll wrote:
Having two 6v GC2 in different locations may complicate the wiring a bit.

I have to agree. I would do it, but I feel capable of handling the wiring.

Most TC are very tight on space, so accessing flooded cell batteries for regular maintenance in 2 different compartment can be a real pain. This is a case where AGM may be worth the extra cost.

What you are proposing is not a very good idea. Many of the reasons why have already been listed above. Another is different temperatures of the batteries will result in different discharge and charging rates, too. Either way, you are going to abuse these batteries and the result will impact their longevity and available AMP Hours and increased charging time.

Also, I would not invest in expensive batteries for this use. What is going to happen is shorter longevity. So, pay more or pay less with the results being the same, shortened life.

Personally, I would purchase two batteries that fit the existing location and go with that. Spend the money to purchase a completely separate battery for trolling use. You are going to end up spending the money that otherwise would have purchased this battery in the long run.

Good luck and thanks for bringing this question here so others can learn from your questions.

b