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Fishing/Fishing accessory (marine battery



With all the fishing experience you've had, I'm certain you have much greater knowledge of this subject than I have.  So...

I've heard them all forever, but I'm not sure what they really mean to the consumer.  So, what do you think is the best measurement (CCA, Reserve Capacity, etc.) to use for comparing value (cost versus usefulness) of a Deep Cycle Marine battery for the exclusive use of powering a trolling motor?

I apologize if the question is poorly worded.  I'm just trying to figure out how all the numbers come together to actually mean something that will help me decide the best battery for the purpose.


Hello Fred,

Thank you for the great question. Forgive me for the delay...numerous days at work and no internet capability combined with the earliest fire season in many years has dominated my time. But, with no further a-do, I'm back...

First off, CCA's or cold cranking amps are only a fair measurement on starting systems...great in colder climates where you are often in temps below freezing...CA's or cranking amps are usually higher because the measurement is done in moderate temps above freezing... so if it is your main or starting bank of batteries, consider CCA's and CA's. Reserve capacity is really NOT either have the juice or you don't...but it is a great marketing gimmick, (even if you can justify the claim due to a capacitor or some type of "reserve" circuitry.

Through trial and error, I have used marine deep cycle batteries from three manufacturers: The Sears Diehard Deep Cycle, Interstate Marine (SRM-29) and Kragen (O'Rileys)31DCM. I was initially purchasing the batteries based upon the price and the manufacturers’ warranty but since warranties are so similar these days, I most often go by price…I’m not proud!  So let's look at what a deep cycle battery is.

As you may know, the deep cycle battery is a battery that is designed to withstand repetitive discharges to a "20% depth of discharge or more and to continue providing its rated capacity" after hundreds of cycles. In my experience, the batteries last longest if completely discharged and then recharged rather than used for the day to say, 40% and then bringing it back to full charge...this greatly reduces the life of the battery and often creates "memory" with the battery capacity being reduced before the cells ever wear out. Remember the end of that sentence...."cells wear out"?  Maintenance is a pretty important thing to consider.

A) Keep the cells filled to the proper level with DISTILLED WATER and check the electrolytes
B) Keep the battery stable. Keep it tightened in a bracket. Impact and vibrations destroy the
  cells quickly.
C) Keep the battery as cool as reasonable...heat also breaks the cells down.

So in lead/acid batteries, I prefer to consider the price, the overall capacity and the warranty. The Interstate SRM29 is getting me about 6 hours run time on a Minn Kota Maxxum 55 at 70-100% power while holding over points in the wind or pounding the banks. 1 amp per pound of thrust per hour on high. This trolling motor has an impulse circuit that really gets you more time out of a charge by feeding juice to the motor itself much like an impact sprinkler waters a lawn...a broken stream if you will, that never lets the rpm of the motor drop but uses 30-50% less electricity. Keep in mind, I am fishing from a small, relatively light boat (+/- 1000lbs)and I do NOT keep my battery on a "maintainer"...I charge it the night before I hit the water and pretty much abuse the heck out of it.

The key is matching the amount of energy to your needs. You can get a LOT more longevity out of a couple of commercial 6 volt deep cycle batteries connected in series than one 12 volt unit. (That's why most golf carts are set up that way.)  But that is a heavy way to go unless you have a boat in which weight is not an issue. Another comparison is the actual size of the battery…this usually means more amp hours or hours of energy at a certain number of amps drawn by the motor. An example would be the Interstate 29M versus the next size up… the 29M is 13”x6.75”x10” and provides 6.2 hours of juice at 15 amps draw. The next and largest size is the 4D is 21”x8.25”x10.125” and provides 11.5 hours at the same, 15 amps draw.

So far, I have yet to invest in the new sealed Absorbed Gas Mat batteries (AGM) like Optima, which are touted as lasting longer than all others, having less memory develop and take a lot more vibration than any other designs...but 200+ bucks each is will have to decide if you can justify that cost. So while they should be more durable, cost versus gain is debatable.

So in a nut shell, until lithium ion technology becomes common place and affordable, I will just let the price, warranty and the overall capacity dictate. With good care and maintenance, most major manufacturers will last a reasonably long time.

I hope all this mumbo jumbo helps...get out and catch'em!

Thanks again for the question.



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Mark Rimmer


I have been actively fishing for forty-five years! For nearly 15 of those years I was able to fish nearly 200 days per year. Those wonderful days have left me with a plethora of knowledge to share. I have fished from the Marianas of the Pacific to the quiet tidewaters of Virginia and North Carolina, Antigua the gulf coast of Texas and many places in between. My home waters are those of the west. I am passionate about bass fishing, tournament as well as recreational. In addition, I am well versed in fishing for most other species...(Okay, although interesting, I'm not an expert on British or European style competitive carp fishing...chumming with a slingshot anyone?). I am intimately acquainted with the San Diego County Lakes, Diamond Valley reservoir in Riverside County California and numerous other exciting fishing waters from Texas (Travis County) to the Pacific Coast and south to Cabo San Lucas. I have many years of experience in blue-water as well as inshore angling of all types in Southern California with both artificial and live baits; high country fishing in the Sierra Nevada Mountains of my beloved Golden State with nothing but a backpack and a fly-rod. There are still a lifetime of adventures to undertake, together with my lovely wife, Christine. I am an expert rod smith and have vast experience with both the construction and repair all types of rods including split bamboo (new or vintage) and hickory as well as graphite, boron composites and all types of fiberglass. I spent 20 years in the retail business of which 6 were spent owning and operating a successful tackle shop, specializing in custom rod making, rod and reel repairs and a full scale tackle selection. Uncommon topics I love to discuss: Fisheries Management; Tackle Shop/ retail management; Ethics and responsibilities of anglers; Repair and maintenance of rods/reels; "How to"...any topic in fishing.


I took a few years off,(5 to be exact) from answering questions for but I'm back now! My experience? Forty-Five years of bio-observation, fishing numerous types of waters with virtually every type of tackle: Casting, Fly, Spinning, Offshore/blue-water, Coastal, Surf, Tournaments: ( Bass, Local Saltwater), Alpine lakes/streams, ditches, canals, sloughs, marshes, creeks and swamps; if there is water, I usually throw a cast or two. Tackle Shop ownership and management, Expert Custom Rod Construction and repair (Big-game, Long-range stand-up, Live bait, jig sticks, Casting, Spinning and fly- including split-cane). I have personally constructed over 700 custom rods of all types...nearly half of the rods the shop turned out. I also have performed hundreds of reel repairs of all types- antique to modern. I do not typically offer valuation of tackle. This is very difficult without inspecting the tackle first hand and leaving valuation far to subjective. I will be happy to offer other experts for placing a value on your tackle.

NRA forever...(Gun rights...Guns and fishing rods belong together right?), belonged to BASS for most of my life but keep forgetting to renew. I like Trout Unlimited but again, keep forgetting to renew...gotta more tank of gas and some fresh line...or memberships? Hmmm.

None yet...why aren't they chasing me?

"Roads" Scholar. Life-long independent study of fisheries biology, ichthyology, aquatic/marine biology, ecosystems, angling techniques and observations of animals, fish and humans: both smart guys and knuckleheads.

Awards and Honors
Self-Proclaimed tackleshop of the year! The California Tackle Box- Oceanside, Ca.

Past/Present Clients
Thousands served!

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