# Deep cycle battery not rated in amp hours?



## Rubber Duck (Aug 27, 2013)

I went to two different places to get a new deep cycle.

I don't want an automotive starting battery, it's why I set out to buy a deep cycle. Deep cycle. Low amp draw, for a long time. That's the application.

But they're all rated in CCA cold cranking amps now.

Here's a crappy low res pic I took of one of them with my antique flip-phone:










It used to be that there were crossover batteries with medium plate thickness that were designed to be used both as a deep cycle and as a starting battery for inboard engines. They were crap. They didn't work well for either purpose.

But you could get a deep cycle and they were rated in amp hours.

That "RC" number, 185 is not the ah rating. Nor is that "20 ah" rating of 100. I don't know that that means either. It can't be 20 amps for 100 minutes, because that would only be 33 amp hours.


I couldn't determine what the amp hour rating was, or even if it was a thin plate starting battery or a thick plate deep cycle. I'm guessing it was one of those junk dual purpose batteries.

So I bought a golf cart battery instead. I need 120 amp hours.

But even the golf cart battery wasn't rated in amp hours. It said "105 minutes at 75 amps". I was able to do the math & figure out it was 131.25 amp hours. 



Could it be that even the manufacturers are too stupid to know the difference between a deep cycle & an automotive starting battery? Or do they just assume that we are too stupid to know the difference ourselves?


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## Peasant (May 18, 2013)

The 20-hour rate is the standard for deep cycle batteries. The batt in the photo is rated for 100 ah I believe, but it should say 20-hour rate, not 20 ah rate, which doesn't make sense. Either way, it's almost certainly not a true deep cycle battery. Marine/RV type batteries are usually just starting batteries, or "hybrid" (which is not really deep cycle). What kind of golf cart battery did you get?

If it doesn't say the amp hours (at 20 hours), it's almost certainly not a true deep cycle battery. There are no regulations on this, anyone can slap a "deep cycle" sticker on a battery, but that doesn't mean it's actually designed for deep cycling. If it has a CCA rating, it's likely just a starting battery. I bought some "deep cycle" batteries from a local big box, they died within a couple months of deep cycle use.

I'd go with Trojans or other true deep cycle battery manufacturers. I replaced my crappy big box "deep cycle" batteries with T-105s. The Trojans only list amp hours at 5 hours and 20 hours. No CCA.


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## Rubber Duck (Aug 27, 2013)

The golf cart battery was a Farm & Fleet model GC2. 

They're never fully charged on the shelf, so I put it on the automatic charger set to 10 amps & it pegged the needle on the charger. I disconnected it & looked it up online & the ---- thing is 6 volts. Nowhere on the battery does it say it's 6 volts. 

So I returned it. Called up an Interstate Battery dealer & their batteries are ridiculously overpriced & the idiot on the phone couldn't tell me if it was a true deep cycle or one of those medium-thickness plate dual purpose junk batteries until "Bob" got back from his lunch break. 

So I just got two Farm & Fleet "deep cycles" rated with a reserve capacity of 120. My old pair were 100. So allegedly this new pair can run a 25 amp load for 240 minutes when paired in a bank.


When that pair is charged I'll have to fill a barrel full of water & load test my trolling motor next to the camper where I've got a digital ammeter that'll show the amp draw.

It's a Minn Kota, 40 lbs thrust. That's all I know.


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## Gray Wolf (Jan 25, 2013)

Most deep cycle batteries are 6 volt. Just get two of them and wire for 12 volt. Much better than a starting battery.

It's all in how you wire them. I have 16 of the 6 volt batteries wired to produce 24 volt power to run our house.

If all else fails, the heavier battery will "probably" be "better" due to more lead in the plates.


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## Rubber Duck (Aug 27, 2013)

Gray Wolf said:


> Most deep cycle batteries are 6 volt. Just get two of them and wire for 12 volt. Much better than a starting battery.
> 
> It's all in how you wire them. I have 16 of the 6 volt batteries wired to produce 24 volt power to run our house.
> 
> If all else fails, the heavier battery will "probably" be "better" due to more lead in the plates.


I was tempted to just get another golf cart battery & do that. I usually run two 12 volt deep cycles & keep them wired parallel. Same voltage, double amp hours. The main reason for using two medium size "deep cycles" instead of one big one is just because of the ergonomics involved in carrying them.

These are for a homemade raft. Not going into too much detail about the SS ******* right now but I gotta carry them from the truck to the raft, then back to the truck, and when I get home I gotta carry them into the camper where my chargers are set up. Carrying two heavy objects (that have handles) is easier than carrying just one because it balances the upper body. Stand up straight & let your fingers do the work.

The golf cart battery didn't have a handle on top so I would've had to make one.


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## Gray Wolf (Jan 25, 2013)

Rubber Duck said:


> You can pick up a carry strap for a couple of bucks for any top-post battery at battery stores and auto parts joints. Cheap and easy way to move golf cart batteries.


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