Trying to decide whether I need to buy a new battery. Just bought a boat with a Group 27 dual purpose starting/deep cycle battery. It may be 5 years old. It spent last Winter outside in Rhode Island.

Put an automatic battery charger on it yesterday. The charger started out at around 10 amps. Then the needle spent the rest of the day and overnight sitting on 4 amps, indicating that the battery was receiving a 4 amp charge all that time. Never got to "fully charged."

Does that fact alone mean the battery is no good? The fact that it takes a substantial amount of juice for a long time, and won't reach a fully charged state. Does the "deep cycle" designation change anything?

I know the right way to determine this is to load test it. But I don't have such a tester. The only place convenient for me to buy a new battery is my local Sears. They have a battery load tester, but the quality is their work there is not good. I'll buy a battery from them. But I'm not comfortable with them touching my stuff.

(They once left a valve stem inside my tire. That was bad enough. But they didn't catch it when I brought it back there a few times because wheel vibrated at speed. And, duh, I was dumb because they got the wheel to balance just fine.)

 

Chris:

Pull that battery and take it to a source where they can test it properly. The newer testers can load test it and deep scan it for possiblity of single or multiple bad cells.

The NAPA I work at does not sell a dual purpose battery for marine use (or any other use). We market marine starting batteries in multiple marine cranking amp varieties and we sell deep cycle marine batteries which are ordinarily used for trolling motor applications.

Rich

 

Most Autozone stores will test it free. Probably other discount auto stores as well.

Dave T.

 

Any local battery store will test for free.....

 

Speaking from a lot of experience..........................

Combination deep cylce batteries are okay but they're not the best for deep cyle use OR cranking. You should use a crank battery for cranking and deep cycle for continuous draw and repeated discharge. Most deep cylce batteries I've had are shot before they are five years old and the same can be said for the dual purpose crank/deep cycle. That also goes for the gel cel types of which I have tried one pair.

One way to find out if it's useful is to put it in your boat and try it. If it was mine, I'd buy another battery (just because of it's age) and advise you the same unless you can walk on water to your nearest battery store for a replacement. Even if you can walk on water, those batterys can get pretty heavy if you have to carry them far.

 

If the battery spent last winter outside and wasn't used there's a very good chance this battery froze. The majority of the time when a battery freezes in a car or boat damage is done inside the battery from cells cracking making for a battery that will not hold a charge. Being in the parts business and with almost 40 years of experience I saw this happen many times. You are correct the only good way to check that battery is to charge it and give it a load test. If the battery doesn't hold the load it is bad no two ways about it but as I mentioned you really need to charge the battery first to see. With a wheel around garage type charger 2 hours is sufficient to charge it before a load test but with a 10 amp charger I usually will leave the battery charging over night before giving the battery a load test.

Told this story once before. This past winter I realized I never disconnected the battery in my Street Rod when I remembered on a very cold night in February. I took the cover off of the car and found the battery was dead probably do to the newer type CD Electronic Radio in the car always needing juice to run its memory and clock. I then proceeded to take the front passenger wheel off of the car to get to the battery to take it out. Once out I pulled the caps and saw that the inside of the battery was frozen except for the 2 end cells that were the furthest apart. I figured it was going to be time to put a new battery in the Rod figuring it had to be bad now since it froze. For the heck of it I brought it into the house and set it in the kitchen sink. My wife already went to bed. I then filled the sink with warm water and let the battery sit there for an hour or two until I could see all the cells were liquid. Knowing I was going to pick up a new battery in the morning I figured what the heck. I really have nothing to lose. It was sometime after 11 pm that night when I saw all cells to be liquid. I drained the water and took the battery out of the sink and proceeded back to my pole barn where the Street Rod is. I then hooked my 10 amp charger and left it over night. The next day I came out and believe it or not I put the load tester to it putting a load into that battery twice for 10 seconds each and to my amazement the battery came back to life. It held the load. I couldn't believe my eyes. That day I put the battery back in the Street Rod and made sure I disconnected the battery disconnect this time that I have in the car.

I took the Street Rod out just a week ago and everything is normal. The once frozen battery turned the car right over without any problems this Spring. This was the first time I ever saw a frozen battery come back to life. Apparently no cells were cracked or I caught it just in time.

 

Sorry, I should have been more clear. My problem is that I cannot get it load tested. I need to make my decision based on something else.

I thought that not reaching a fully charged state after being on a charger for 16 hours should tell me something. Don't know though. I'm stumped.

 

Chris: At the risk of being considered as smartazz, what do you mean you can't get it load tested? Are there no facilities in your area that can load test a battery when you carry it in?

In my experience people with boats have limited time available to use the boat and want to enjoy that time on the water instead of at the dock making repairs. Buy a good quality battery on your way to the boat and install it when you get there. Quit beating yourself up on whether or not the current battery is servicable. Happy boating.

Rich

 

Buy an Optima Red top & then you can forget about battery problems, installed a red top 4 years ago on my 66 BB, it has bever been on a charger even following winter hibernation she starts right up ..workes for me ,
The Dog

 

Being you can not get the battery load tested I would say get yourself a new battery. Don't chance it. 16 hours on a battery charger was more then enough I would say. The battery should of held a complete charge by now. Hopefully your are not using a trickle charger usually only putting out 1 amp. If that isn't the case junk this battery and get a new one. Maybe check out a Harbor Freight and pick up a load testor down the road. If you are not looking to spend a lot of money this is the place to go to get a Chineze copy of a Milton #1260 Battery Load and Charging testor for under $20.00. Money that would be well spent in your case.

 

Even at 1 amp, 16 hours should have it fully charged.

Get a new one.

 

I need to make my decision based on something else.

I thought that not reaching a fully charged state after being on a charger for 16 hours should tell me something. Don't know though. I'm stumped.[/QUOTE]



Sorry to leave you in the dark. I thought I was reasonably clear:

"One way to find out if it's useful is to put it in your boat and try it. If it was mine, I'd buy another battery (just because of it's age) and advise you the same unless you can walk on water to your nearest battery store for a replacement. Even if you can walk on water, those batterys can get pretty heavy if you have to carry them far.:


(just because of it's age)
(just because of it's age)
(just because of it's age)
(just because of it's age)