Dead battery question

X2 there toast.

path1 wrote:
Really don't want to pull battery and take to auto part store to test if I absolutely don't have to.

You probably have to.
You probably have to get a new one too.
It probably went dead in the first 2 weeks and just sitting there DEAD for 6 months would cause a lot of sulfation, which will cause total failure fairly soon.....even if it does appear to charge up OK.

Bite the bullet now or it will bite you later.

My advice for the best hope of recovery with a green light charger, is to unplug charger when green light illuminates, and load battery until voltage drops below 12.6v, then restart charger, then remove load.

Lather rinse repeat.

Even if you get all 6 cell's Specific gravity to the 1.275 range, and it rests at 12.77 volts 24 hours after removal from charging source, it is still likely very capacity compromised.

It is like a shrinking gasoline tank. you can still fill it up to overflowing, but when new it held 20 gallons, now it might only hold 8 gallons, and it will never hold 20 gallons again despite the marketing mumbo jumbo on the charger's website.

But to even get it to hold 8 gallons will likely require the lather rinse repeat trickery cycle, and could ultimately be a waste of time and electricity. But it could be a good learning experience if you get familiar with manipulating your green light charger and dipping a hydrometer and watching a voltmeter as you apply the load to reduce voltage when tricking the green light charger into resuming the attempt to hold and maintain absorption voltage.

A group 27 flooded battery will likely have 'deep cycle' plastered on its sticker, but it is at best a marine battery, closer in design to a starter battery than a true deep cycle battery. Flooded 27's are Much harder to fully charge, requiring longer times at higher absorption voltages, and much less resilient to over discharge or less than full recharges.

But the 'just finers' will crawl out of the woodwork claiming how much battery life they get from them. In another thread they might also post that their MPGS are twice everybody else's, and that their flatulence smells like roses. Their arms are frequently in slings from spraining them patting themselves on the back.

You've got nothing to lose. My advice is if at the end, you believe the battery is "good", prove it - turn on some lights for eight hours then re-check the voltage. You don't need to have a moment of discovery halfway into your next trip. Think on the positive side if all goes ill with the resurrection attempt: The battery was more than middle-aged to begin with.

Rest minimum 12 hours after charging. 24 hours is better.

Green light doesn't mean much. Measure voltage on disconnected battery after 12-24 hours, together with SG.

Most likely you've lost some capacity, but could be still usable for a season or two if you don't demand too much from it.

Yea give it a go. Disconnect and charge. Rest 24 hours and check voltage. If the charger has an equalize function use it after the normal charge. Most likely you will be down exchanging the batteries for new not testing them.

When lead acid batteries discharge fully and are left discharged, the Plates usually sulfate and the batteries will never return to their full state of charge and longetivity. What you DO, with Deep cycle batteries is charge at the rate they discharged. That means you charge at the lowest rate your Aftermarket Battery Charger will charge it and then do a Hydrometer test. That will tell you the condition of the batteries after a full charge. If just one tests bad, you replace them all. Doug

Charge it as you're doing and check after a few hours. That will tell you a lot.

You're referring to a hydrometer, not a hygrometer.