won't stay charged

my friends 99 range rover 4.6 hse, the battery will not stay charged. we replaced the battery, and the same thing. what could be draining the battery?

Bad alternator, take the truck down to your local auto parts store and get it tested.

i think the battery looses it power while the car is off. could it still be the altenator

either that or you're leaving the headlights on.

no, thats the thing that that i dont understand, everything is off.

i can do diagnosis with you but you need a dvom to test draw?
dvom stands for digital volt-ohm meter.
radio shack has cheep ones.

Hi Roverboy3776.
Disconnect the battery when parking it at night and see if the problem persists.
Regards
Marius.

The same thing is happening to me right now.  My battery is dead and I am stuck here at the moment.  When I sit inside the car with it turned off, I can hear a buzzing sound in the dash, which leads me to believe something is not turning off properly and drawing current from the battery.  Not sure what to do now.

install an Optima Yellow Top battery. There are so many electrical/"discharging" problems with RRs, this is the only reasonable solution I have ever heard. The dealer will tell you to replace the battery, and use the Interstate model, but the Optima is much better (and unfortunately $50=$75 more) it is especially bad if you park in a garage with a bunch of cars like I do in NYC. The "security" system on the RRs go crazy in this environment and all of the signals for the other cars alarms and keyless locking make the RR think something happening so it uses battery juice constantly until the battery dies. The Optima Yellow Top works for me on my 02.

Leaving the auto gear selector in any other position OTHER than 'P' will tend to drain the battery.
 
Just a thought to check. :)