Diagnostic Auto Electrician Billericay -not a mobile service

[Andy 308GTB]

2019 MG3 has a drain on the battery. Dropping 0.1A overnight but will flatten the battery in 3 days if left in an airport carpark... It's on it 3rd battery in a year (as I assumed the battery was at fault). Now fitted with an expensive Yuasa battery but the problem persists..

Following the standard procedure, as detailed on multiple YouTube videos, I can't find anything.
I then got a mobile electrician in who spent an afternoon going over the car but could find nothing.

I'm thinking that I need a garage with more than just the kit that a mobile electrician carries. Suggestions, please!

[oakdale]

Andy 308GTB said:

2019 MG3 has a drain on the battery. Dropping 0.1A overnight but will flatten the battery in 3 days if left in an airport carpark... It's on it 3rd battery in a year (as I assumed the battery was at fault). Now fitted with an expensive Yuasa battery but the problem persists..

Following the standard procedure, as detailed on multiple YouTube videos, I can't find anything.
I then got a mobile electrician in who spent an afternoon going over the car but could find nothing.

I'm thinking that I need a garage with more than just the kit that a mobile electrician carries. Suggestions, please!

I'm sure I've read in several places that a software update at the dealers can often be the answer to this common problem.

[Andy 308GTB]

Thanks very much for that - something I would never have thought of.