2nd battery D2, no worries...beside the turbo, on the firewall, do a search here and you will find various posts.
see Traxidetronics web site index7 for battery controller etc
Drivesafe is active on the forum and will be able to help I am sure. Battery.... I supply Optima batteries to listers all over the country, so have a look at Optima Blue Top and you will get all the specs etc, then PM me and I'll give you a price, courier delivery etc...
2002 L322 Range Rover TD6, silver paint, leather seats, power to spare, sunroof, electric mirrors, rear parking sensors, ride almost as good as a Citroen, ... luxury
Aussie '88 RR Tdi300 (+lpg), Auto (RIP - awaiting new body)