Deep cycle or starting battery

[Bayou Dave]

I am sure this topic has been beaten to death, but here goes anyway.
My deep cycle battery will not hold a charge. CCA 550, MCA 685, reserve 140 minutes.
It was purchased by PO about 2 years ago. I maintained it last winter and this winter by charging it up every month. It will charge up to about 12.78 volts but drains to 10.5 volts within minutes.
When I unplug the charger, wait an hour for it to settle, and put the voltmeter on it the volts go down one by one until it bottoms out in the 10's. This only takes a couple of minutes for it to go that low.
I mainly use the battery for starting, fish finder and use the radio sparingly.
Since I feel that I need a new battery (I will have it tested at Autozone) would I be better off getting a starting battery or go with deep cycle again?

 

[JustJason]

Re: Deep cycle or starting battery

If you don't ever want to get stranded, and have the room for it, do both. Get a starting battery for the engine, and then an automatic charging relay and a deep cycle for all of your accessories. That way you can run the fishfinder and radio until the deep cycle is as dead as can be, and you will always be able to start the engine every time, and never get stuck.

 

[haulnazz15]

Re: Deep cycle or starting battery

I see no reason to have a deep cycle just to run a basic radio and a depth finder, as they are pretty small in power drain even after a couple of hours. If you are operating an electric trolling motor, then I would definitely keep two separate batteries.

My ski boat doesn't have the space for a second battery, so we've always just used a starting battery. We've never had a battery go dead on us, even while running the radio for a couple hours while anchored. Granted, we don't generally spend a lot of time sitting still, but as long as you run the engine enough to recharge the battery you'll be fine.

 

[alldodge]

Re: Deep cycle or starting battery

I am sure this topic has been beaten to death, but here goes anyway.
My deep cycle battery will not hold a charge. CCA 550, MCA 685, reserve 140 minutes.
It was purchased by PO about 2 years ago. I maintained it last winter and this winter by charging it up every month. It will charge up to about 12.78 volts but drains to 10.5 volts within minutes.
When I unplug the charger, wait an hour for it to settle, and put the voltmeter on it the volts go down one by one until it bottoms out in the 10's. This only takes a couple of minutes for it to go that low.
I mainly use the battery for starting, fish finder and use the radio sparingly.
Since I feel that I need a new battery (I will have it tested at Autozone) would I be better off getting a starting battery or go with deep cycle again?

^^ +1 agree, if you do want deep cycle just get what is called dual purpose marine. It would be my guess this is what the PO put in the boat. Also try to get the highest CCA you can find for your size battery (Group 24 or 27). Sure CCA is not the ture measure but it is something to look at when your shopping. As pay attention that some show CCA at 32 degrees and others show it at 0 degrees. Try to compare at the same temperature, and stick with a marine type due to vibration

 

[UncleWillie]

Re: Deep cycle or starting battery

.... It will charge up to about 12.78 volts but drains to 10.5 volts within minutes.
When I unplug the charger, wait an hour for it to settle, and put the voltmeter on it the volts go down one by one until it bottoms out in the 10's. This only takes a couple of minutes for it to go that low...

You are not charging the battery! 12.78v is not a charging voltage.
The charger must be able to deliver a voltage in the high 13's to even begin to charge the battery.
14+ is more typical. Check the charger and its connections again.

The bad news is that a battery that spent the winter below 11 volt may be a goner in any event.
Unless you already have a shorted cell in the battery, Resolve the charger issue before buying a new battery or it may Deja Vu all over again.

 

[Bayou Dave]

Re: Deep cycle or starting battery

The 12.78 was measured at the battery after taking the charger off. I did check the charger this morning and it is putting out 13.65. I would rather see over 14. The major issue is that the battery is discharging at a huge pace. For it to go from 12.78 to the 10's in minutes with no load on it makes me believe it is shot.
There is no room for a 2nd battery, barely have enough room for the one.
AllDodge...When I was searching every auto parts store in my area I didn't see any battery listed as dual purpose. Could they be listed as something else, other than dual purpose?

 

[alldodge]

Re: Deep cycle or starting battery

The dual purpose name could have changed again in the battery industry, don't know but did find using google. Either way as others have mentioned, you really don't need a deep cycle. A good start battery will work fine

Marine Batteries | AutoZone

 

[Bayou Dave]

Re: Deep cycle or starting battery

The dual purpose name could have changed again in the battery industry, don't know but did find using google. Either way as others have mentioned, you really don't need a deep cycle. A good start battery will work fine

Marine Batteries | AutoZone

Thanks for the link. That one never showed up when I was searching autozone yesterday.

 

[ktbarrentine]

Re: Deep cycle or starting battery

I switched from deep cycle to starting battery in my 5.0L 20 foot chaparral two years ago and have been very happy with it. Runs my radio and fishfinder for hours and starts the boat very nicely. Diehard 24MS 560CCA. Just my 2 cents.

 

[royston22]

Re: Deep cycle or starting battery

My 2 cents worth would be to get a starting battery or a deep cycle or both. A dual purpose battery will serve neither purpose particularly well.

 

[Lurch77]

Re: Deep cycle or starting battery

For what it's worth, my pontoon has only a start battery. I bought one of those portable jump start packs, keep it charged, and take it on the boat with me. I run my radio all day, and the motor doesn't get run very often. I start it at the landing, cruise to the fishing or swimming area, and shut her down. I figured with the short run times (meaning short battery charge time) and radio use all day, the battery would end up having issues. It never did, and I never had to use the jump pack all season long. It's interesting that I bought the jump pack for the boat, but ended up only using it on the motorcycle.

Adding a trolling motor or other equipment that would severely drain the battery on a regular basis would require a good deep cycle battery. Otherwise a start battery will likely do what you need. And these portable jump start packs are 1/2 the price of a second battery, let alone the extra wiring and set up you'd need.

 

[Starcraft5834]

Re: Deep cycle or starting battery

your battery wont hold a charge? sometimes they just go bad........I've got (2) deep cycle batteries, one for engine and one for fishfinder.. one for fish finder not necessary? yep.. but........ if engine battery has an issue, I guess it's nice to have that second one around too "better to have than not need than need and not have"...

 

[Bayou Dave]

Re: Deep cycle or starting battery

I pulled the trigger and got rid of the battery. It just would not hold a charge. I ended up getting a dual purpose one at Autozone for $104.99. New one has 800 CCA, 180 reserve minutes. My old one at 550 CCA did really good until it went bad. The new one at 800 CCA should fire it up real fast.
Thanks for all the replies and thanks to AllDodge for the link to the new battery. Dave