Flat battery resulting in need for roadside assistance

[steveg]

When returning from holiday (4weeks, very lucky) the car is “dead” and I have to call roadside assistance, this has happened 3 times. Anyone else experienced this, what was solution??
Volvo have said this shouldn’t happen!!

[Stovo]

What model and year is your XC40? This will help responses from those who have had similar issues and fixes.

[Deleted User 4737]

Battery could have a cell gone but normally, especially if its a Hybrid, all manufactures say it shouldn't happen. The reason, manufactures fit far too smaller capacity 12v batteries in their Hybrids, 4-weeks not using and they are flat. Solution, don't leave it unused for so long or keep a NOCO GB20/ GB40 Jump-starter close by. Other Jump starters are available, but these are the simplest and best.

[Devonal]

My B4 ultimate was only two weeks old and had done about 200 miles when one morning it was completely dead. Got assistance eventually, was told to take the car to the dealer. The Dealer could not offer any explanation other than ‘probably a software issue’. Not happened to me since, but I still get flat battery anxiety at times. Our drive is a bit tight, so I don’t park with the passenger door too close to a wall as that will make it difficult to get into the car to open the bonnet, as I discovered! If I recall correctly, flat battery problems have been reported before, so Volvo must know this is an issue. If I have not used the car for three or four days I start it up, and even take it for a short run, just in case.

[Cevoli21]

As this is posted in the EV section I am assuming yours is fully electric like ours. This happened once to us when it was around 3 months old. Had been stood unused for 10 days, charging cable attached but not charging. Completely dead. No response to key. Would not unlock. Managed to get in via emergency key but everything was dead. Volvo on call turned up. 12v battery showing less than 2v. Would not take a charge from his booster pack or cables connected to his van. He spent 90 minutes puzzling how to get it out of the garage as could not release the parking brake. He was on the verge of calling a second team to put it on rollers when it sprung back into life. Checked over by dealer - nothing abnormal found. Possible software issue. Dealer said should not leave it plugged in but the manual says you should when leaving it for some time. Doesn't really inspire confidence in service team. Volvo tech said he had been to 3 cars in the previous seven days with the same issue. 2 were Polestars but basically the same. It's been fine for the past 18 months.

[Deleted User 4737]

They fit small 12v batteries, probably no bigger than 35-amp, this keeps all the 12v functions going drawing amps even when not in use, only takes a week or two to deplete the battery. The drive batteries then re-charges the 12v when in ready mode.

[EmJay]

I use, on a weekly basis if my mileage is low, a battery charger/conditioner as my previous car (BMW X1) would die if I didn't travel enough. So, using the belt and braces routine I use the CTEK MXS 5.0 Battery Charger with Automatic Temperature Compensation, Black. Available on Amazon.

[Cevoli21]

I too have a CTEK 5 but on the EV it's very difficult to get to the 12v battery. Various covers must be removed/dismantled. It's designed to stop owners getting anywhere near the electronics. We have since left it unused for 4 weeks and it was fine so perhaps the software idea was not to far fetched.