I'm waving bye bye to 5Ltr SC heaven (and the ludicrous VED charge) and picking up a new (to me) 2020 P400e AB on Wednesday. The vast majority of my car use is short journeys, all of which will be done using EV only mode. Longer journeys requiring the petrol engine will only be every 2-3 months. Can anyone definitively state whether or not the 12V battery will be kept charged by the main battery, or will I need to plug my C-TEK in every so often? Does it also have a 'secondary' battery for the auto stop/start? I've asked various motor trade people about the 12V charging and got contradictory answers. I'm having a Ghost immobiliser and tracker and a Thinkware 790 dashcam fitted on Thursday, so there will be some moderate battery drain whilst it's parked. I notice it still has the remote charging terminals under the bonnet, so clearly LR doesn't think they're redundant.

The state of the 12v batteries affects how frequently the engine starts. It has a stop start battery on the right side of the boot, and a full size 12v battery under the floor in the boot (near the actual hybrid battery). I’ve recently replaced mine as they were both the original batteries from new (6 years old). Doesn’t use the engine anywhere near as frequently now. 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

Thanks, Hoppy. If I'm reading that correctly, it suggests that keeping the 12V topped up with a C-TEK will reduce the number of times the engine powers up to recharge it, so in turn, reduce petrol use?

Not really hijacking the thread but why do people always show the p400e as having high fuel consumption. I always thought with a bit of granny charging and very short journeys fuel consumption would be pretty much 0. Probably was highjacking - sorry  Geoff

Yes to the ctek charger, but if the batteries are good you may not need to.

I got a hybrid as I’d tried fully electric (Audi etron) and couldn’t live with the range anxiety when away from home.

With off peak charging it’s pennies to top up a hybrid and living in Manchester means lots of traffic and short journeys. Mines only just started working well a it took a while to figure out then change the 12v batteries. Before that I was getting around 60mpg, now it’s more like 100. On a long run it’s like any petrol though and in the 20s if you drive it normally. 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