My little Carly device reckons the stop start battery is at 65%. Mines a hybrid so I think this affects how frequently it runs on electric.

If I was to change it, does it need coding to the car like the big one does (is that still a thing?). I don’t have a gap tool so would I have to go to LR?

Looking at Europarts, they do a decent Bosch auxiliary battery for about £67. Does this sound correct? My Previous RR's!
2018 P400e Autobiography
2008 TDV8 Vogue
2006 TD6 Vogue
2007 TDV8 Vogue
2007 RRS (I know, it doesn't count!)
2005 4.4 Vogue on LPG
2005 TD6 Vogue
2003 4.4 Vogue
2001 4.6 HSE
2000 2.5 DHSE
1999 4.6 HSE
1997 4.6 HSE on LPG
1995 2.5 DSE
1989 3.9 EFI classic
1988 3.5 EFI classic

It does not need coding. Be aware that the auxiliary battery failure leads to braking failure with no warning and disturbing messages such as: drive with caution, ABS not available, HDC not available, etc.

Thanks a lot for this! Glad I didn’t wait that long for the brakes to fail then  My Previous RR's!
2018 P400e Autobiography
2008 TDV8 Vogue
2006 TD6 Vogue
2007 TDV8 Vogue
2007 RRS (I know, it doesn't count!)
2005 4.4 Vogue on LPG
2005 TD6 Vogue
2003 4.4 Vogue
2001 4.6 HSE
2000 2.5 DHSE
1999 4.6 HSE
1997 4.6 HSE on LPG
1995 2.5 DSE
1989 3.9 EFI classic
1988 3.5 EFI classic

https://www.rangerovers.net/posts/2444524/

https://www.fullfatrr.com/forum/topic65051.html

Thanks, I changed the stop start battery today with an exide one from europarts, it was £90 and easy to fit. Original LR one was exide so hopefully no issues. My Previous RR's!
2018 P400e Autobiography
2008 TDV8 Vogue
2006 TD6 Vogue
2007 TDV8 Vogue
2007 RRS (I know, it doesn't count!)
2005 4.4 Vogue on LPG
2005 TD6 Vogue
2003 4.4 Vogue
2001 4.6 HSE
2000 2.5 DHSE
1999 4.6 HSE
1997 4.6 HSE on LPG
1995 2.5 DSE
1989 3.9 EFI classic
1988 3.5 EFI classic

This 12V dependency of hybrid/electric cars is disturbing, I have an acquaintance that had a terrible experience with his Tesla: "it died in mid Spain, some acid lead backup battery used for brakes and interior electrics broke and the whole car will not start without it … , you need to replace it every 2-3 years … no warning... cannot change it myself as it voids warranty... have to tow the car to a dealership..."