AGM battery help?!

[t6lownslow]

Hi chaps

I have a AGM leisure battery which after a month of sitting unused dropped to 1.94v, not enough charge to display on my built in volt meter display.

When I’ve connected it to my smart charger, it display a bad battery light (see pic) after connecting it also to my van battery, the volt meter display jumps to 12.9v but fluctuates to 13.9 and back…

A) do I need to be worried about the bad battery light or is it too soon to tell?

B) is fluctuation ok?

Thank you for help! This is a lot of stress before going away

 

[Pete C]

You probably need to replace the battery. Allowing an AGM battery to get that low is very bad for it.

Pete

 

[Pauly]

The bad battery light is prob because it was so flat

Flatter it gets and the longer it stays flat the more damage that is done, getting the voltage that low is highly likely to have damaged the battery, you may be able to get a charge into it but i suspect it will never regain full capacity

 

[Dellmassive]

As above, running the battery that low will damage it.

You may be able to recover some of the capacity back...

But might need to connect a doner battery in parallel with the charger to recover it.

Moving forwards, look at fitting an isolator switch to the battery if the van is being left for long durations.

Or ensure all loads are switched off.

 

[Dellmassive]

Fyi, easy fix to get you on your way.

Replace the AGM with a new one and get on your trip.

 

[t6lownslow]

I do have an isolator attached, only thing that bypasses that is the smart charger and the parallel connection to the van battery which is still spot on. If I left it connected to the under bonnet battery and and the smart charger to the dead battery and attached another smart charger to the unsee bonnet battery, charging both simultaneously, would that work/help?!

 

[t6lownslow]

Thanks for your responses!

 

[Dellmassive]

Got some pics of the setup?

 

[t6lownslow]

 

[t6lownslow]

It’s one of the wired campers kits, they’ve been brilliant troubleshooting a few bits too.

After disconnecting both battery completely, testing them with a multimeter, both are showing as 11.9 (van) and 12.4 (leisure), connecting it all back up the smart charger doesn’t display the bad battery light anymore and is charging?!?! I understand even tho this maybe work the leisure battery could be damaged and not hold charge for as long as it did… so I’ve ordered another just incase, the test will be next weekend when away camping without EHU

 

[Dellmassive]

was referring you you specific van and install, but that pics shows a

also. . .

this connection should be fused.

 

[t6lownslow]

I do have an inline fuse on that connection lol, I think I have sussed it out I’ve disconnected the setup and left the smart charger on for few days (result, still knackered) disconnected the leisure battery completely to test with multimeter, when reconnecting it (I realised the smart charger was still on) and it started charging, left it for a few days again and the voltage gauge was reading fine and all appliance and sockets were working fine!

Been away in it this weekend and the fridge was on for the entire time without EHU, battery worked fine!!! Thanks for all your posts and help.