Had my NX300h for three months. AA has attended 3 times to jump start it due to a flat battery. True I only drive it short journeys about 4 times a week but it is getting to be a real pain. Taken it to Lexus Bristol 3 times. Their response is ‘drive it more or put it on charge’. Their website states categorically that I will never need to charge it. Do I have to dismantle the boot each time to get to the battery or is there an alternative?