Yes I am talking about a D4 3.0l, same engine as the RRS.
No it's not that one, at least the model No. is different.
The new battery fitted by the dealer is an Exide battery with a Jaguar sticker on it. Model No. is BH42-10655-BA which must be an OEM number because a search of Exide's Australian, UK and US web site shows that model No. is unknown.
A web search for this model No. shows a few hits but they are almost all foreign language web sites, eg Batterie EXIDE Technologies SAS EK920 pas cher - Démarrage et Charge : Batteries de démarrage - Batterie EK920
A translation of the page says this battery is designed for vehicles with 'Stop and Start' technology. Just what I need :D

