Is my Battery Dead?

System
System Posts: 2,511 admin
in Energy Use & Conservation #1
I'm hoping the battery experts on this forum will be able to give me an answer.

I bought a Deep Cycle Battery last September and used it on a camping trip. I ran it until it ran no more.

Here is it 9 months later and I have plugged it into the charger. and nothing seems to be happening. The Charging light won't come on, not to mention the Charged light.

I have read through a few of the FAQs here and other places and I'm starting to get the creepy feeling that I was supposed to have charged my battery immediately last fall, and by leaving it empty all these months, I've killed it....

It's a Deka Dominator 8G22nf , my charger is a Cliplight deep cel charger #31103 and when I used it last fall, it said it had 51 AH and I used it for about 45. (My Cpap machine draws about 2.5 AH and I used it for 3 six-hour nights)

How do I dispose of a battery again...?

Sigh... You can respond to me off list at savagela@pacbell.net

Thanks in advance for your suggestions

Mark
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Comments

  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    #2
    Re: Is my Battery Dead?
    I bought a Deep Cycle Battery … and used it on a camping trip. I ran it until it ran no more. Here is it 9 months later … and I'm starting to get the creepy feeling that I was supposed to have charged my battery immediately last fall, and by leaving it empty all these months, I've killed it....

    Mark,

    The combination of a severe (~90%) discharge and letting the discharged battery sit for many months has almost certainly killed it due to sulphation. You can recycle the battery at virtually an auto parts store. Should you decide to replace the battery, the vendor may give you a recycling credit on the old one.

    There are three of the key rules to long battery life. One is not discharge it below 50%. So, if you need 45 Ah, start with a battery rated at 90 Ah or better.

    A second rule is to recharge the battery as soon as possible after use. For example, if you use the battery while camping, recharge it as soon as you get home, and top it off at least once a month. If nothing else, the full battery will be a back up power source for your CPAP machine in the vent of a power outage.

    Third, make sure you use a charger designed for your battery. The Deka 8G’s are VRLA “gel” batteries, and they require a lower charging voltage than a VRLA GM or a flooded-cell model.

    Sorry about the bad break…

    HTH,
    Jim / crewzer
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,485 ✭✭✭✭
    #3
    Re: Is my Battery Dead?

    Definitely shot. The only thing I could imagine to add to the massacre would be between September and June is letting the deeply discharged battery exposed to freezing temperatures.

    Discharging creates lead-sulfate 'moss' that over a period of weeks crystalizes. Once the lead sulfate crystalizes it is very nearly impossible to get it to revert back to lead and sulfuric acid by recharging.

    The best way to store a battery is to put a trickle charger which maintains the battery (assuming a 12 v, six cell battery) at a voltage of about 13.3 vdc. Alternately, do a top off charge every few weeks.

    When you measure the no load battery voltage that has not be loaded or charged for 6 to 10 hours, it should have a voltage of 12.7 vdc when fully charged. Once this open circuit 'rested' voltage drops below about 12.6 vdc due to self discharge then sulfate formation begins.

    When you buy a battery, first check to be sure the voltage is not below 12.6 vdc. If it is, don't buy it.
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  • System2
    System2 Posts: 6,290 admin
    #4
    Re: Is my Battery Dead?

    I once read that most lead acid batteries do not die, they are murdered.
    Unfortunately, this is an excellent example of battery murder.
    We all learn from mistakes, so better luck next time.
    Wayne
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  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    #5
    Re: Is my Battery Dead?
    When you measure the no load battery voltage that has not be loaded or charged for 6 to 10 hours, it should have a voltage of 12.7 vdc when fully charged.

    That's valid for 12 V flooded cell batteries, but the "full" voltages for VRLA batteries are higher. According to Deka, a full AGM battery is 12.8 V - 12.9 V, and a full gel battery like the 8G22NF is 12.85 V - 12.95 V.

    HTH,
    Jim / crewzer
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  • kc8adu
    kc8adu Solar Expert Posts: 50 ✭✭✭
    #6
    Re: Is my Battery Dead?

    i deal with these batteries dialy.
    i have seen wheelchairs run dead and stored till the estate sale and they bring them in to "see what happened to it"
    i set my regulated bench supply to 15v and current limit to 2a and hook it up.
    often after a week or so they come around.you likely have one of those on off voltage senseing chargers and the battery is well below detection.
    try a dumb trickle charger for a week or so.
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