INTERSTATE Deep Cycle Marine Battery

[CharBaby]

Greetings!
My neighbor gave me,(no lie, a brand new looking) INTERSTATE Deep Cycle Marine Battery(FLA) from 2017 which is rated atop the battery info, 800CCA/1000MCA. He must'a bought it and never used it, just sitting on a shelf. There are no witness marks on the battery posts. It looks unused!

Just sitting in his garage it read/holding at 12.5v. I took it home and put it on my battery maintainer/tender and after 4 hours, it read full at 13.7v and the maintainer light was in the green, meaning fully charged and a good battery.

However, after just sitting(maintainer still connected) the battery voltage drops down to ~12.9v and the maintainer kicks back on to bring the voltage back up. After several hours, I completely disconnect the maintainer for the overnight and checked it this morning and the battery is still holding at 12.67v.

My question is; is the battery good?
Can I sell it, should I keep it or should I turn it in to AdvanceAutoParts for a free $10 gift card?

 

[joekingcorvette]

I would sell it. Battery maintainers have a way of shutting on and off all the time and that is no reason to believe it's not a good battery. You probably won't get a whole lot of money for it due to the age but someone with a boat or other use could certainly get some good use out of it. I would probably try to sell it for $30-$45. Due to the age it's not going to bring top price. Anyway nice catch and good luck with your sale!

 

[fantastic]

Take it to oreilly's Auto & have them load test this battery.

 

[meep]

Battery may have useable life. Connect it to an old headlight (3 amps) and see if it runs it at least overnight, say 12 hours. A healthy deep cycle will be able to. Then let it charge for a week.

 

[repairman54]

I just pulled my 5/19 dated cranking Interstate marine battery off the shelve to put it back into my boat. Its been on a Battery Minder during winter storage all it's life. HF old style resistor load tester passed it with a 400 CCA reading, still in spec.

 

[CharBaby]

I am keeping the battery on the maintainer. I am(now) noticing that when the voltage reaches 13.6v-13.7v, the maintainer turns off(stops charging) and the battery is holding a higher voltage while resting. I want to see if after a week or longer, the battery will hold closer to 13.4v-13.5v when I disconnect the maintainer. Then I will take it into Oh-Oh-Oh O'Reilly's for a load test.