battery info

I need another battery for my dodge 3500. At Cosco they have several to chose from. Marine deep cycle batterys at 750 cold cranking amps, or standard battery at 500 cold cranking amps. for a little more I can get the marine deep cycle battery. Will this be any benefit for the deep cycle Battery? Thanks stan

Well here's what you should look for:
When it's time to buy a new lead-acid car battery, there are four key criteria to consider:

Age: You don't want to buy a car battery manufactured more than six months ago. The manufacture date will often be on the battery, in code. The letter indicates the month (A = January, B=February, etc.) and the number indicates the year (9 = 2009, 10=2010, etc.).
Group size: The group size describes the battery's dimensions and terminal orientation. It should match the size of your old battery.
Cold cranking amps (CCA): CCA measures the amperage a battery produces at 32 degrees Fahrenheit (0 degrees Celsius) within 30 seconds. The higher the CCA number, the better the battery will start in the cold. Don't confuse this with the cranking amp (CA) number, which is a less accurate figure.
Reserve capacity: Perhaps the single most important criterion, the reserve capacity lets you know how long the battery will run if the car's alternator dies. It's measured by checking the amount of time in minutes a car battery can hit 25 amps while maintaining a steady voltage of at least 10.5 volts.

The main difference between a deep discharge battery is that they are designed to be discharged down to 20%. "Normal" starter batteries are designed to provide a quick, discharge for starting, then be recharged.

Personally, I don't think the deep discharge batteries are a good fit for what you want to use it for.

Deep cycle batteries are usually for low load over a long time. Used in campers to run the lights, ref., and other low comsumption uses. They are often used on boats to run trolling motors.

They will start your engine but you would be better served with a normal automotive battery.

If you want a battery used for starting a vehicle (high current delivery burst for a short duration), YOU BUY ONE THAT WAS DESIGNED ENGINEERED AND BUILT FOR THAT PURPOSE i.e. a regular automotive battery.

If you want a battery designed for lower amperage slow deeper discharges like for a boat trolling motor or an RV house battery YOU BUY A BATTERY DESIGNED AND BUILT FOR THAT PURPOSE, i.e. an RV/Marine so called quasi deep cycle battery.

TRUE either one will still "work" but NOT best in an application they were NOT designed for.

Those are the engineering facts, we report now you decide, its your money and your choice, go for it.

John T Retired Electrical Engineer

A deep cycle battery is made to be used till dead then charged back up and go again and will not last long if used in a car or truck. You need a true car/truck battery not a battery made to run a trolling motor or RV

Costco has lots of stuff, but it is not the place to find an industrial application battery. I agree with what the others said- don't get a deep cycle. I've had good luck (and good prices) on Interstate, and NAPA batteries. You should be looking for 650 CCA at a minimum.

And you don't need another battery- you need 2 batteries. Always replace both batteries when one goes bad- because the new one will soon tank the remaining old one. Best to just start out with 2 new, it'll work out better in the long run.

Stan,

Does your 3500 have one or two batteries? If has two, you should replace both. Paired batteries get replaced in pairs. A weak one will bring the other one down. The reason that I ask, my 12 volt Cummins' have two, somewhere around 800 - 850 CCA each. One goes, they both get replaced. I go into the auto store and go with the highest rating Group 27 that I can find, which these days about a 72 month pro-rated warranty and about $125 a piece plus core last time I got a pair a couple of years ago.

Good luck.

Mark

(quoted from post at 01:24:29 10/31/13) I need another battery for my dodge 3500. At Cosco they have several to chose from. Marine deep cycle batterys at 750 cold cranking amps, or standard battery at 500 cold cranking amps. for a little more I can get the marine deep cycle battery. Will this be any benefit for the deep cycle Battery? Thanks stan

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I have had good service from the yellow batteries from Wally World.

Also starting a regular automotive engine with a deep cycle will often ruin them. They are only designed to put out maybe 100 amp max. Not the several hundred amps a large engine requires to start.

Get as many CCA that you can afford/have space for.