I have a 50lb thrust trolling motor 12V that needs a battery before I can use it.

Looking at standard deep cycle marine batteries and I’m finding some different ones with different cold cranking amp ratings. Does the CCAs make a difference in run time, power output or performance on an electric trolling motor?

For example, I’m seeing 850 CCA, 650 CCA, 340 CCA, 250 CCA etc. I read somewhere online that a 55lb motor draws up to 40 amps peak. If that’s the case and I’m understanding this correctly, the 250 CCA (cheapest one) should work just fine as the motor will not even come close to that in energy draw. Or is there more to it than that?

Will a 650 CCA or 850 CCA allow faster charging times, longer run times, or have any effect on performance of the motor or any other benefit or is it just a complete waste of money?

I know with automotive, for example, 250 CCA would probably have a very hard time starting a big V8 truck engine and 850 CCA would be overkill for a little 4 cylinder hatchback. But this battery will not be starting an engine. It will be running a small electric motor over extended periods of time so it’s a completely different animal from a cranking battery that needs to start a vehicle.

Also want to add, looks like marine grade batteries come in cranking (which I know for a fact I don’t want), deep cycle (which I know would work great), but there also seems to be a lot of batteries out there advertised as dual-purpose deep cycle and cranking. Surely one of those would be fine, I’m assuming.

Just seems odd to me that there are batteries that are made for both purposes 2-in-1, since deep cycle are made to be charged and discharged and cranking you typically want to keep topped off all the time. I haven’t bought a marine battery in a long time so maybe the battery tech has changed and batteries now can do each purpose well without issue?

Well what are you going to be installing the motor on? Size of boat, and will you be running fish finders also? A small group 24 deep cycle will work if your using it on a small rig and not running the motor on high all day. If you running fish finders and trolling a long ways on high a group 27 would be a better choice. I could fish all day with a 27 running my 16’ Jon with a 50lb thrust trolling motor and one fish finder. Same battery and motor on a little 10’ bass buggy would last all weekend. Wind, current and range of travel all come into play.

It’s an Alumacraft 1036 and the trolling motor will be the only accessory being run off of this battery.

Plan on only fishing stillwater - ponds and smaller lakes with it. I don’t want to deal with current on a river or big swells on a large lake as this boat is tiny.

A group 24 deep cycle will be fine. Or a 27. Weight difference is only about 5 lbs

I found a group 27 deep cycle battery with a 750 MCA rating for a good price that I’m leaning towards. It seems like good value and should have a long run time with my boat/motor combo.

cranking amps have nothing to do with run time, look for reserve capacity or amp hrs. (ah).

a deka grp 27 deep cycle would run it all day and then some.

look at the dc 27 on the chart.

https://www.eastpennmanufacturing.com/wp-content/uploads/Marine-Master-Spec-Sheet-0194.pdf

Go with a Deka AGM

Go to Walmart and get the $99 Marine battery with the 2 year warranty. For the price they are hard to beat.

The more AH and Reserve Capacity the better. I have a #55 and run it off of an Exide 31 series. It runs everything on my boat, graph, stereo, and live wells. I can run two days without charging, haven't tried three days yet as I remembered to plug it in at the end of the second day. I wouldn't go smaller than a 27 series.

Two different battery technical reps told me to use the dual purpose for the engine and electronics - AGM and the deep cycle - wet cells for the trolling motor application.