I have a stelvio from 2021!! it is going to be 2 years old in a month!
My battery holds only 20Ah of charge! no issues yet.
As it was showroom (vitrine) car. seems they left it a few times go under!
Battery goes from full charge to 12.05volt in 5 days (100mah drain, typical forthe car) or 24hours with my dashcam in parking.
Measured all and is about 400mah total drain! this makes it barely 10amp/24h drain!
Thinking of an AGM but I do not know which company to go with.
I found some strange facts on the car.
Some simple test:
What I did was, to put a Clamp multimeter in Negative pole. with a phone camera streaming! and recording it.
Then I locked the car, closed trunk.
Car has:
1. 12-18amp consumption for a few minutes!
2. goes down to 5amp for another 4-5 minutes
3. slowly the next 10minutes falls to 0.150ah consumption...
4. finally after 1 HOUR! falls to ~0.08ah (80mah)
Unlocking the car kicks a 22AMP! for 30sec the above cycle begins.
I would only trust the battery voltage once the first 10minutes pass
Using an Intact I logged the battery voltage over time.
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Left red circle: dashcam: 450-500mah drain! falls to fast
it fall in 10h from 12,73v to 12.2!
right red circle: no dashcam, still falls, not so visible.... the deeps is every unlock! (goes to 22ah)
Blue: Tender on (CTEX MXS 5.0) 5ah loading.
Tender put about 12ah of load
What battery?
Thinking VARTA G14 Silver Dynamic AGM 595 901 085 but maybe another?