I recently had a no start followed by an ignition lock.

Seems the culprit was low battery voltage in the end (feel free to read about it here - https://www.fullfatrr.com/forum/topic70963.html).

The battery is an oem one by Excide, guessing a few years old but never had any issues and I keep it topped up by charging it if the car is not driven for a while.

However for no good reason it lost voltage (down to 11.4v when it failed on me). I charged it up and a day later it read 12.12v, 24 hours after that it read 12.01v.

So I am losing around 0.10v a day. Guessing that’s not normal. I am yet to have the battery tested but I can’t help but feel something is draining it when the cars locked and sleeping.

What should be the drain over 24 hours? (minimal I imagine)

What are the first things to check?

And what’s the best procedure to check stuff when the cars open?

Thanks in advance, Kit. 2009 pre-facelift 3.6 TDV8.

surely the first job is to check the battery before you go looking for other faults. At least then you'll either find your problem or have something known to be good to work away from. Onto my 2nd FFRR, this time an L405 5.0L SC AB in SVO Palette black.

Yes, I am looking at getting a charger that tests battery health (Ctek Msx 5.0) as I need to upgrade my simple battery charger anyway.

But I thought I would ask the question preemptively because I had a perfectly good battery one week, then one that suddenly loses power the next.

The only thing that has been used recently that has had little use before is the air-con. I had it re-gassed as it didn’t blow any cold air. Now it works fine, but I have read that the air-con unit can often be a culprit in drawing power if faulty. Again something I will look into (fuse 12) having just read about - if the battery checks out. 2009 pre-facelift 3.6 TDV8.

MY04 Range is always connected to a CTEK MXS 5 when I'm not driving it, there are any number of battery drains on these earlier cars, good luck finding the culprit !

I have a battery drain, there are a few good strings here on how to track down the culprit if you do a search. You need a clamp meter on the battery negative, put the car to sleep and start pulling fuses.

I've narrowed mine down to two fuses in the passenger fuse box, Fuse 12 which serves the AC control panel and Fuse 57 which feeds the air suspension. New (old) ac control panel on its way to me to see if that solves/reduces the problem. I found that if I pressed max cooling with the ignition off the heater fan came on..

One cause of battery drain that I've read about in many threads is the final stage resistor (FSR) for the heater/ac fan aka the 'hedgehog'. Its fed from fuse 64 in the passenger fuse box, not causing mine though. All the best
Chris

Thanks.

I tested the Max button and nothing happened.

Will look into the others you mentioned. 2009 pre-facelift 3.6 TDV8.

I am still waiting for my Ctek charger to arrive to health check my battery, but noticed it’s an AGM spec version (see below), obviously I don’t have stop-start! Guess this is not a problem, I certainly have had no issues over the past 2 years with it.

It was fitted by a LR dealer in 2016 according to the service history, hoping that all my issues are down to the age of the battery after finding this out, not sure I will be that lucky however.

Is there a ‘best battery’ for these cars? My plan is to replace it with the Exide equivalent.

Although this non AGM Excide one that came up after putting my reg into Tanya seems great value…
https://www.tayna.co.uk/car-batteries/exide/ea1000/

Click image to enlarge

AGM trumps all other types. Keep it  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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Don’t install an AGM battery unless the car has an AGM compatible charging system. 2012 TDV8 Vogue (L322)

I guess the question is does a pre-facelift 2009 model have an AGM charging system?!

Guessing the dealers would not fit something incompatible?

My vin starts with SALLMAM239A in case that tells anyone anything. 2009 pre-facelift 3.6 TDV8.

If it was dealer fitted it's certainly the right one but 10yrs old likley past it's best. I'd replace and then see how it goes with regards to voltage loss over time. 2012 TDV8 Vogue (L322)

Interestingly this place sells the oem AGM replacement battery (at a hefty price) and quotes that it fits L322’s from vin 7A…

https://www.steveparkers.com/product/lr094...0cca-90ah/

Click image to enlarge

Another thing that may explain my issues is that having only recently found out I had an AGM battery I may have somewhat ruined it by charging it up with a standard Halfords charger - which I read is not suitable voltage wise.

If nothing else I have learnt a lot the past week… 2009 pre-facelift 3.6 TDV8.

Get an AGM one from Tayna and do the battey update procedure in the GAP IID tool so it can do the cycle charging properly. 2012 TDV8 Vogue (L322)

I don’t own a Gap IID tool, what is the best value one to buy that will do most of what I need it to do?

Prices seem to vary when looking online. 2009 pre-facelift 3.6 TDV8.