We will not be using our 2015 RRS for a period of three weeks. Should I connect it to a smart charger during that period, as I do not want to come back to a flat battery? 2015 Range Rover Sport Autobiography Dynamic SDV6
2012 Range Rover Sport SDV6 HSE Luxury- Santori Black with Autobiography Ebony/ Ivory interior- SOLD

Wouldn't harm. 

Mine sat on my drive from mid-July to 1st week of September with no problems. So long as there are no frosts you should be OK but if there is a cold snap then the smart charger would be worth connecting up to. Mine goes for up to 4 months without use and no problems in the summer but I ensure that it gets driven for 30-40 miles every 4-5 weeks during the winter when I am working abroad just to top up the battery and keep everything exercised. One tip is to make sure that when you park it before going away lower it to access height and then double lock it, that will send all the electronics into sleep mode and help reduce battery drain. If you don't lower it and lock it then walk away the electronics will not go into sleep mode and will stay "awake" in case you come back to the car soon, also the car will gradually lower itself as the air drains out of the air suspension system, better to do that before locking up. 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Tim, when you leave for longer period (over a month), does it still unlock as normal, or do you need to use the key blade. My FL2 used to shutdown its Central Junction Box completely after 30 days to conserve the battery having to use the key blade to open the car after 30 days.

The only time I have had to use the emergency key blade was after my 1st Evoque's battery died after 2 days parked up! LR (not the dealership) told me that my LR TracStar must be draining the battery so it got hauled to the local dealership where it was put on a test rig and it was found that it wasn't the tracker causing the problem it was the BMS software! That Evoque was one of the very first in private ownership and that was the only issue I ever had with it - rapidly draining batteries which was resolved by changing the BMS software and fitting an AGM battery. I never had an issue after that. With RRS2 I have not had any reports from my brother who takes the car for a run every 4-6 weeks while I am away that he has not been able to unlock the car using the fob. I just wish LR would re-enable one of the power points when the engine is off so I could plug in my solar panel trickle charger but they seem to have an aversion to doing it. Trying to cure my Evoque's battery issue they were able to reprogrammed the BMS so the socket on the centre consol remained live and that was a big contributer to stopping the flattening batteries as I could trickle charge the car on my drive. As said even after 4 months I haven't had an issue getting the car started, but it was summer time. 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

My 2015 MY often sits in the garage for 4 weeks at a time and last year it didn't get used or started for 7 weeks. Starts fine every time and never had to use the emergency key to open her.

Jas Current RRS: MY18 SVR
Previous RRS: MY15 RRS 5.0L Autobiography

Thanks for the information. As the car will be in a garage, I will run a smart charger, just to be on the safe side. 2015 Range Rover Sport Autobiography Dynamic SDV6
2012 Range Rover Sport SDV6 HSE Luxury- Santori Black with Autobiography Ebony/ Ivory interior- SOLD

I've just come back from 2 weeks abroad and admittedly to a cold spell but my enginr struggled to come to life.

I expected instant start! Was I being too hopeful? RRS (MY13) Santorini Black SDV6 HSE luxuary
Gone: Evoque, Freelander 2, Mercedes 320 CLK, Porsche 911's

Cold is always bad news for batteries sadly.

I use a CTEK charger using an adapter I got from the Disco forum which connects to my tow bar. Means I can lock the car in the garage and leave it hooked to that. It always seems to stay live. I left it for a few weeks but not longer. MY16 3.0 SDV6 Autobiography in Aleutian silver, stealth pack and toys.

If you have to replace it then look at fitting one with a high CCA (Cold Cranking Amps). My 20 year old Defender's LR standard battery couldn't handle the recent cold snap until the temperatures warmed up and then it was faultless, but I decided to replace the battery with a higher CCA and even when we had -6C last Friday it turned first crank when the day before the old battery (which was only 18 months old) and was a CCA 55 couldn't turn the engine over. 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW