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DrewWalker

New Member

• Aug 19, 2013

• #1

I have a 99 4.0 and the battery goes flat after 3weeks as I work away and not started during that time. I have changed the drivers and passenger door locks all works with remote and checked the bctm goes to sleep checked the Rf unit and it is the upgrade unit any suggestions.

 

kevwill

Active Member

• Aug 19, 2013

• #2

How old is the battery??
Always best to fit the biggest/best one you can.
I had a Halfrauds battery that lasted just 14 months. Bosch one has lasted 3 years so far with no probs.

 

T

TCubed

Active Member

• Aug 19, 2013

• #3

Get an ammeter either in series, or a clamp meter, to measure the current draw. It should be something very small (13mA?). If it is then it points to either a duff battery or a dying alternator. (Alternator should deliver 14.2V at 2k rpm)
If there's a drain, do you have anything aftermarket fitted?

 

Datatek

Well-Known Member

• Aug 19, 2013

• #4

Draw should be 30ma when the BECM is asleep. Unless you have a 135ah battery in good condition, 3 weeks is about as much as you can expect. You need a solar panel or a smart charger.

 

T

tomcat59alan

Well-Known Member

• Aug 20, 2013

• #5

I used to have the same problem as I to, am away for long periods. First I bought a battery as recommended by Datatec and use a smart charger (£14 from Aldi) and I have never had a problem since. Hope that's not the Kiss of Death.