The problems with my G1’s (XTR) were a mixed bag of great battery life then the replacements bombed, warrantied one that lasted only a few weeks & one that was working ok but then put bike away over winter & when got out in warmer conditions it wouldn’t work.
I have still got a G1 ultegra that is alive & kicking though even when I thought it was dead & its over 2yrs old now, during winter rides on the road I have cut out a section of old inner tube & slipped this over the crank & battery cover dunno if that helped ?
@mrblobby tbh the course was that technical I could hardly see the output except on the climbs & I forgot to turn the Garmin on so didn’t get all data for performance management chart after :-/