I keep getting battery low and the tv / radio turning off when sat waiting for swimbo shopping etc, the battery is about 2 years old, after a run it seems to read 12.3 volts most of the time, I used a multi meter and my battery drop tester on it today 12.3v but when I put the load on the drop tested for the required time it sits in the green ok part, always starts the car even after 2 weeks just sat there, I’ve got an iid tool is there anyway to check it’s been told it had a battery fitted two years ago, any alternator checks I can do on the drive (in isolation again 😡), thought I needed a new battery but the drop test says it’s a good battery it just sits low at 12.3v 2012 Range Rover Westminster 4.4 TDV8
2006 Discovery 3 HSE 260k miles and still going strong with a new owner

What's your alternator throwing out, battery should be at 12.6 to be considered full charge...

I can’t go for a drive due to being in isolation again, it will sit for two weeks and start on the press of the button as soon as I’m out of isolation I’ll plug the iid in but just wanted some pointers on what to look for snd to see if the car was told it had the new battery 2012 Range Rover Westminster 4.4 TDV8
2006 Discovery 3 HSE 260k miles and still going strong with a new owner

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Last edited by ur20v on 4th Oct 2021 2:59pm. Edited 1 time in total

My 4.4TDV8 does the same, just waking the car up, say I'm washing it and opening each door in turn, I get a message telling me to start the engine as voltage too low.
My Radio / cd / tv all power off after a short time without the engine running.

Think of a water tank in your loft, if you have a shower, loads of pressure, flush a toilet downstairs, shower is now half pressure, turn on a tap or two and you're down on pressure again - for me it would be dripping now.
The water available in the tank is still pretty much the same but the pressure is split between all the outlets.
It's the same with electrical voltage from a finite source such as a battery.
Think of voltage as water pressure. (Flow = amps btw)

These FFRR's have so many electronics that turn on just by waking the car up, that alone is enough for the voltage to drop to a point where mine says start the engine!
Add in a radio etc- it's just like someone turning on another tap, voltage (pressure) drops.

I'd say trust your tester, it's a proper test to check battery condition - if it's green your battery is good Anything can be made to work if you fiddle with it long enough (and have deep pockets|)
Current cars, 2011 FF 4.4 TVD8; Audit TT 1.8T convertible.