Dead Battery??

Pezman · 10-27-2018, 08:36 AM

OK, I probably know the answer, but I need some confirmation here. Charged my battery. Put it back in my Jayco Hummingbird. It showed 12.5 as a charge. Went to put the slide out and it went about 2" or so. Then nothing. Checked battery and it showed 10.5. Took battery back out. Put it on charger and it charged for about a minute and showed 12.5 again. Put it back in Hummingbird and same thing happened. Slide moved about 2 inches or so and nothing. Checked battery and it's back to 10.5. Is the battery bad, shorted or whatever????

WinnieView · 10-27-2018, 08:44 AM

Take it and have it tested and if needed the same place will have a replacement.

Pezman · 10-27-2018, 08:48 AM

Thank You. That's probably what I will do tomorrow. We decided to get one more quick camping trip in next week and I definitely have to have a good battery!

oldmanAZ · 10-27-2018, 09:09 AM

I'm sure you'll hear from other members (and I see you already have

).

Do some research on the internet regarding batteries and their state of charge. You will probably be happier in the end and your (new?) battery with thank you.

GrumpyDad · 10-27-2018, 09:53 AM

Figuring out WHY your battery got ruined will help you a lot when you have your new battery. Properly cared for, they should last a lot of years. Improperly cared for, well, I hope your battery store has a forgiving warranty program, because you'll be back there often.

as a note, 1) resting voltage of a fully charged battery is 12.8V if there's no draw on it. A battery should hold that voltage for a month or more when disconnected.
2) All trailers and RV's have some parasitic drain, and you need to fully disconnect the batteries between trips if you aren't hooked up to a charger.
3) batteries should be charged via shore power before and after every tip. You can't rely on them charging sufficiently while driving.

RogerR · 10-27-2018, 10:55 AM

A battery tender like the Battery Tender Junior model will keep the battery at top charge for the minimum amount of power if it is disconnected from parasitic drains.
Not really intended to charge a battery that is discharged, just to maintain it.

GHen · 10-27-2018, 11:00 AM

First, I’m not an electrician, I DO have a lot of general experience in deep cycle batteries dealing with a hundred of them at a Sporting clay range. My comments are basic just for understanding the issue. I’m sure true electricians will make some corrections to my comments.

When my batteries get to 12.5 or below I immediately get them charged back up. From what I have seen true Deep cycle batteries are fully charged and healthy at around 13.1 volts. Regular car batteries or those hybrid batteries that some claim as deep cycle/starting batteries are at full charge just above 12.8.

When a battery is checked immediately after having a charger attached, it will show an incorrect voltage charge. It needs to rest after charging to get a true reading. Your 12.5 volts right off the charger is probably only 12.2 volts, which is still considered dead in my opinion. Dropping to 10.8 is damaging and/or indicates that there may be a dead cell. There are 6 cells, each are around 2 volts, so 10.8 plus 2 for a dead cell gets you back to 12.8 which is where it should be after charging.

I think your battery is ready to be traded in as a core on a new one. You can give it one last chance by charging it overnight. In the morning, disconnect it from the charger. 30 minutes later check the voltage, if it’s not between 12.8 and 13.1 you probably need a new one.

Pezman · 10-27-2018, 06:09 PM

Thank you for your reply. I think it's a dead cell. As soon as it's charged and I hook it up to the camper and try to extend the slide, it's dies. Not holding a charge.

GrumpyDad · 10-27-2018, 06:14 PM

Quote:

Originally Posted by GHen

First, I’m not an electrician, I DO have a lot of general experience in deep cycle batteries dealing with a hundred of them at a Sporting clay range. My comments are basic just for understanding the issue. I’m sure true electricians will make some corrections to my comments.

When my batteries get to 12.5 or below I immediately get them charged back up. From what I have seen true Deep cycle batteries are fully charged and healthy at around 13.1 volts. Regular car batteries or those hybrid batteries that some claim as deep cycle/starting batteries are at full charge just above 12.8.

When a battery is checked immediately after having a charger attached, it will show an incorrect voltage charge. It needs to rest after charging to get a true reading. Your 12.5 volts right off the charger is probably only 12.2 volts, which is still considered dead in my opinion. Dropping to 10.8 is damaging and/or indicates that there may be a dead cell. There are 6 cells, each are around 2 volts, so 10.8 plus 2 for a dead cell gets you back to 12.8 which is where it should be after charging.

I think your battery is ready to be traded in as a core on a new one. You can give it one last chance by charging it overnight. In the morning, disconnect it from the charger. 30 minutes later check the voltage, if it’s not between 12.8 and 13.1 you probably need a new one.

This sounds like someone who knows more than me. Good info here.

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