Battery is D-E-A-D...Dead! I left it and didn't love it or play with it for WAY too long. I left it at a friends house for a couple months stored in his garage. Good thing I didn't pass away! Someone could have had a nice dusty barn find in a few more decades.

Anyway, the battery is kaput. Not even responding to the CTEK that I keep with it is getting it to respond. After a few minutes, the CTEK just shuts down. Any thoughts, prayers, heckling, tips, voodoo? Should I connect the CTEK straight to the battery? Go for the RECON mode? I really don't want to try to find a replacement battery out here in the boonies.... Help me Obi-wan (or whoever), you're my only hope....

 

Try leaving the CTEK plugged overnight and check again next day if it revives the battery. I had a Jeep that did that and CTEK revived the battery overnight. Worth a try, otherwise, you are in for a new battery. Good luck and keep us posted.

 

Most of the time automated chargers such as the Ctek will not respond to batteries that are deep discharged though they do go slightly lower than a 0% State of Charge - usually around 10V or so (I haven't had a Ctek in quite some time as I found they would go kaputt as quick or quicker than their cheaper Chinese imitations). AGM batteries like the one in your Defender are deep discharged under 0% SoC at a voltage of under 11.65V, though I don't have the exact specs on the LR battery so this could vary slightly. I assume your battery will be considerably below that.

I have recovered AGM batteries that were discharged to an extremely low level (below 10V) using an automated charger such as the Ctek. You have to bring the voltage level at the terminals to a level where the Ctek responds and begins charging. One way to do this is to use jumper cables to the terminals under the hood from a running vehicle or a big battery booster. Once the Ctek begins charging you can usually remove the jumper cables and let the Ctek work.

There are several things to be aware of:
- one of the reasons automated chargers don't charge batteries discharged to a state this low is that there is the possibility of a thermal runaway (fire!). While this is much less likely with an AGM battery than a lithium battery, the possibility does exist.
- with the method I described above you will be subjecting the 12V system in your Defender to a range of voltages and with the real possibility of voltage spikes (such as when attaching/removing jumper cables or even from the Ctek). While the 12V system in a modern LR is much more robust than most people think, do whatever at your own risk.
- the AGM battery will have sustained damage due to the deep discharge even if you mange to recover it. It may work ok in warm weather and if you run the motor very regularly, but I would not rely on the battery if you're going to do things like leaving the car at an airport for more than a day or 2 - especially in winter.

The main reason I described the recovery procedure above is to get you out of wherever you are and back to somewhere where you can have the battery replaced. And I would do this if it were my vehicle and I needed to rely on it in any way, shape or form.

 

Sorry to hear grouse, I got the same 2 weeks ago. Recharged it twice.. did not keep the power anymore.
So search for the Exide EK960 - direct replacement with breather tube input ( bonus it's 96ah )
I did pay in Euro's 167,40 including delivery.

 

Thanks for the tips. After trying to charge it over night. No bueno. I then slapped the CTEK back on it but again, no good. At this point, I'm punting. The problem is, the dang thing is not EASY to get to. I guess I'm going to jump it one last time to just be able to scoot the passenger (I'm US spec) forward as much as possible to get to it. Time to dig out the old JLR workshop manual and see if I have to take out the F'ing seat to get to it. What happened to the old hand crank behind the seat that I could just slide thru the bumper to start the darned thing?

EDIT: Good 'ole Simon at PowerfulUk!! I definitely owe him a pint some day. He would never pay for a drink in any pub I found him in. His video: .
Now to find a freakin' E14 socket....I just laugh at the madness JLR puts me thru.

EDIT #2: Found this thread. Should have started with the Advanced Search! Thanks for all the tips in this. Link. @Dogpilot or anyone else who've done this. How much of a PITA to pull out the battery without removing the seat? Can I get the both leads off first or do I take off the black/negative first, slide & remove? Hoping to get this done without resorting to an E14 seat removal....

 

@GrouseK9
You don't have to remove the seat. Just an extension socket with 10mm to losen the 2 bolts of the bracket. Wiggle this bracket out.
Slide off the breather tube at the end ( leave the red elbow coupling in the battery for now )
You can slide the battery up and out, but it's heavy - watch your back.
After the battery is out remove the red elbow coupling - this is going into the new battery.
New battery in, wiggling the bracket to the correct position. Connect the breather tube and the positive and negative poles.
Use your GAP IIDtool to set New Battery.
I expect with my use of Winch,Fridge, Converter, Aircompressor max 4 years of lifespan..

 

A 10mm socket fits the E14 seat bolts nicely. I unbolted the seat and leaned it forward when I replaced my battery.

 

We don't have this model in North America, at least I couldn't find.
Not to mention Exide back in a day wasn't a good brand. I'd like to know also which one would fit nicely and be better than OEM.

 

You mention using a GAP tool to ‘set’ the new battery. I was wondering for those of us without a GAP too, what are you resetting, and what happens if you slap a new battery in without setting it. I’ve read previously of other posters replacing the battery and seeing no difference, having no problems. Yet others claim it needs to be reset. Can anyone clear up this divergence in information?

 

Reset to New Battery is only for the BMS, so the characteristics / data of the old battery will be erased. To adapt learning the New one