P38 Battery problem!!!

Hi folks I would like some advice if anybody can help. I have a diesel P38 Range Rover that does not like the cold weather but works the rest of the time. As soon as the temperature at night drops the battery decides it does not have sufficient power to start the engine in the morning. I am now on my second battery in 18 months. After a charge from a charger the vehicle starts and goes on all day with no problems. I always turn the key and when the glow plug light goes out I count to 5 before starting. I find that this usualy solves all starting problems
Now I know this may sound daft but when I looked out of my bedroom window this morning I saw the whole of the vehicle was covered in ice except a small fan shaped area on both the drivers and passenger front windows. It looked like the vents on the ends of the dashboard had demisted the corner of the windows by the wing mirrors. The vehicle was in the shade so any early morning sun had not affected it.
Is it possible, with all the complicated gizmo’s on the P38, that something is going on with the air vents that may be draining the battery?
I know it may be a stupid suggestion but I am clutching at straws.

What size battery have you fitted? Diesels take a lot of cranking power when cold. A 110 amp hour battery with a cold cranking amps of 980 or better should do the job. The bigger capacity the better.

Could be the BECM is being woken up and draining the battery, something that would be more critical in cold weather. You could disconnect the blue wire from the RF receiver under the rear drivers side parcel shelf as a check.

Can't see that anything could demist the side windows unless the heater fans were going. Check the engine compartment fuse box for signs/smell of burning

I am having the exact same problem! Ever since I changed the battery in my key I have had all sorts of problems.

Hi there.
You should have a 664 or 334 type battery depending on your year P38. The 664 has a higher AH but the 334 (as also listed for a TD5) is specified for later post 99 models.
I have had a few starting issues with my 99 diesel during this cold weather.
My battery Volts were 12.2 V( nearly flat) at -1 deg c. I will be buying a new battery soon , but for now I have added some bat Aid tablets to de sulphate the battery plates and now my voltage is up to 12.4 which does not sound alot but equates to a big jump in battery capacity.
Check your battery type and voltage first thing in the morning before you start the engine and see what it is. this will highlight any battery issues before you look elsewhere.

Poppers said:

I am having the exact same problem! Ever since I changed the battery in my key I have had all sorts of problems.

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I think he means Engine bay battery! :doh: