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  1. #1
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    Deeply discharged battery

    I am usually very good about not discharging the batteries too far and getting them back on the charger as soon as possible in order to maximize life. Earlier this week I screwed up.

    I was in the garage working on moving waypoints and when I was finished I turned off the graph but forgot to turn off the main power and the network. I didn't find the mistake for a couple of days. At that point I shut everything off and checked the battery voltage before plugging in the charger. It was down to 11.98v.

    Battery is the Duracell AGM Group 31. It appears to have charged up without a problem and has been holding at 12.92v. Can I expect this battery to fail sooner than it would have without this issue?
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  2. Member
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    #2
    I think it will be fine. My electronics did that to my cranking battery often until I got a house battery for just them.

  3. Member 06 SB's Avatar
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    #3
    You will be fine. Plug it in and check it about 4 hours later for sulphur smell.

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  4. Member
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    #4
    Should be fine. I think that you would have to deeply discharge it numerous times to really affect its longevity.
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  5. Member
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    #5
    Thanks.
    2006 Triton TR196 w/ 200 Optimax \ 2021 AlumaRyder 1860 w/ 200 Rotax

  6. Member
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    #6
    When you see permanently damaged in documentation it is true, but that might be a month earlier 5 years from now. The idea is to not do that regularly because it will add up. Not to fret! Bob
    Tell me where has a slow movin' once quick draw outlaw got to go

  7. Electrical/Wiring/Trolling Motors Moderator CatFan's Avatar
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    #7
    Quote Originally Posted by bobcoy View Post
    When you see permanently damaged in documentation it is true, but that might be a month earlier 5 years from now. The idea is to not do that regularly because it will add up. Not to fret! Bob
    ^This pretty well says it. Average depth of discharge is the key factor. You had a spike on the low side, but getting it back to full charge ASAP and keeping it there as much as possible is what determines battery life.
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    #8
    Plus, I think the fact that it's an AGM helps. Supposedly able to handle slightly deeper discharge than flooded.

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    #9
    Not all agms are equal. The TPPL AGM's are(Odyssey Extreme type), but any lead acid battery will retain capacity longer by not deeply discharging or leaving the battery any where less than 100% charged. Some are less damaged by it but still damaged. Get used to doing it and you will buy batteries less often. JMO Bob
    Tell me where has a slow movin' once quick draw outlaw got to go

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