Just out of curiosity, do you lock your rover and do all of the door locks work?

Had a Porsche that drove me absolutely, well nearly, insane...once. Sometimes, it would be fine after sitting a few days or barely start the next time, cranking over slowly or be dead. Battery was brand new, charging system good, etc. Checked for battery draw, normal, below spec. But, the scenario continued. Finally, a pattern developed. I'd left the car unlocked for a couple weeks, which wasn't normal. Jumped in, assuming there would be low battery...and it cranked over strong. Hmmm? Next time, l left it for a few days and locked the doors...low battery. Hmmm? Unlocked...fine, locked...not so fine. So, checked for battery draw...with doors locked...bingo-bango...huge draw...turns out...the passengers electric lock motor wasn't finishing its cycle, pulling door lock all the way down...so it was continually trying to lock the door, causing battery draw.

Lubed internal linkages of door lock and issue went away.

 

@The Deputy I do lock the Disco we have some low level drug users who steal from vehicles, not common but they will always look for open vehicles. I can try that from 8:00 am to 11m and see if there is a drop.
The battery is a 3 years old AGM - but I think it has always been dicey even though the store where I bought it claimed it passed after the 1st time it went low.

Voltage after unlock was 12.22 rising to 12.30 after 20 minutes with the negative disconnected - not unexpected as those 4 computers & my VHF radio have some draw and I did the interlock test is in position 2, engine off. I believe .8 drop is about right.

I cleaned all the grounds and found some corrosion on the positive and the mid point negative ground slightly fouled.

The negative cable battery end needs cleaning and tinning it is no worse than any 18 year old truck and I have the tools to do it.
The positive could use the same

Currently the battery in on charge with the negative disconnected, so I can check if it can hold a charge disconnected.

Did the tests in position 2 with no issues not lights.
I did not do a start test as I need to test the battery.

 

Unless l'm not understanding your test procedure here...

​​Parasitic draw should be between 0.02 - 0.05, this would be acceptable.

0.8 is a huge draw, not acceptable.

Checking parasitic draw is done with DVM, with meter on milliamp setting, disconnect negative cable, let vehicle go to sleep, connect meter cables between neg post and neg cable.

 

@The Deputy I have been watching the Battery voltage drop this am I test the parasitic .1 - .1 so high now the fun begins. I mis-spoke before that .8 drop was from having aux circuit on while I tested the transmission functions.

So hopefully this will help others my issue was my bluetooth ODB dongle it was pulling .12-.14 of volt with it removed I drop to.03-.02 instantly
However my battery may also be getting weak it dropped from 12.6 to 12.45 in less than 12 hours disconnected so it may have issues but it under warranty still so I can get it tested

Thanks for chiming in another voice always helps

 

Good news, glad you found the issue. Yeah, when l read 0.8...l was like...wow...Huston, we got a problem...lol. Heck, 0.12 is huge also.

 

The final news is after cleaning all the ground and battery connections up, replacing the end on the negative side, and up and tightening things up on the alternator I am charging in the 14.4 range at the alternator and a battery which is up from the 13.9 - 14.1 range. 13.9 to 14.1 at the ODB port so the Disco is a happy camper again.

 

We love happy endings around here!

 

I had the same problem with the Veepeak OBDII adapter I bought to use in my other car. Couldn't figure out why the battery was failing. I didn't anticipate the Veepeak being the problem since I don't have the same problem leaving the UltraGauge plugged in in the Rover.