Battery has gone flat 3 times in past 3 months. Has been into dealer and had electrics checked and a module changed. Also had a new battery fitted as part of a recall for cars fitted with the auxiliary/remote heater.

Today had charged battery overnight with my CTEK 7000 battery charger, drove car out onto drive, turned it off and put on the auxiliary heater to warm it up. 20 minutes later came out and battery wouldnt start engine.

have now disconnected battery to give a recon charge with the CTEK.

if this doesnt work....

Would changing battery help, have a 90Ah battery (BMW) fitted. Looked on internet at 95Ah AGM battery £140. This would be easier/cheaper than going to dealer for tests/ new battery etc even though still under warranty. Would fitting your own battery affect warranty?

Anyone else fitted a new/ better battery

duncan UK. X5 E70 3.0D