Difference between deep cycle and starting batteries?

[Robj]

Hello,

I just bought a new battery for my boat, to start the engine not for trolling. The battery that I bought is a deep cycle. While at the store today, I noticed that some batteries were deep cycle/starting, starting or deep cycle. Is there a difference between a deep cycle or marine starting battery? Is this deep cycle suitable to be used as a starting battery?

Thanx for your help. Have a great day.

Rob.

 

[Boatist]

Re: Difference between deep cycle and starting batteries?

There is a difference. In general starting batteries and designed to provide lots of current for starting. Also a starting battery should not be discharged below 80 percent of full charge. Starting battery plates are thinner so they can get more in each cell and provide more current.

Deep cycle have thicker plated so also provide less current for starting. Deep cycle can be discharged down to 50 percent without real damage.

Can a deep cycle be used for a starting battery? The answer is usually yes. Rule of thum is battery should have as many starting amps as your engines cubic inch displacement as a bare minumin. Some like 2 times the cubic inch of the motor. So if you have a V8 350 cubic inch or 5.7 L and your battery has 700 cranking amps you just fine with a deep cycle. If a 4 clynder 181 cubic inch or 3.0L then you need to have 362 cranking amp battery.

Real question is do you need the deep cycle. Regular auto starting batteries are much cheaper and if installed in the stern where they do not get much pounding they hold up just fine.

My 1980 3.0L 181 cubic inch 4 cylinder 140HP has always used a auto starting battery and a Deep cycle house battery. I have never had a battery that did not last 6 years. Both are group 24 but I do not have a electric trolling motor on this boat. Actually even my deep cycle has been a auto deep cycle.

 

[Robj]

Re: Difference between deep cycle and starting batteries?

Thanx Boatist,

I checked the deep cycle battery that I bought and it is a 685 cca. My motor is a 2.3 litre Volvo. So the battery should have no problems cranking it over. It was cheap at Costco.

Thanx for your help. Have a great day.

Rob.

 

[Ebb205]

Re: Difference between deep cycle and starting batteries?

The fact that it has a cca rating tells me it must be ok for starting. I have a seperate deep cycle, it does not have a cca rating, just amp hour and reserve amps for ratings...