Leaving car for 4 months during winter

[dazza1168]

Hi All,

I am going to to be overseas for 4 months during the winter 2023/24 and am planning on leaving my 2016 RX450h at my brother's place during this time. I had read a lot of the posts on solar chargers for Battery top up but not sure if this would work during a long UK winter. The car is usualy driven daily and I have left it at the airport for 4 weeks before without any issues. I am not sure this would be sufficient for 4 months so woud appreciate any input on whether a solar trickle charger would work or get my brother to give it a run once a week if he can?

Thanks in advance

[rayaans]

Doesnt need a run necessarily. Just get it turned on for 10-20 minutes every 10-14 days. I cant imagine a solar trickle charger working  very well in winter

[NemesisUK]

The official Battery maintenance advise below..

 

Maintenance of hybrid battery.pdf

[Spock66]

Apart from the Battery a regular run will help clearing rust off the discs and the tyres getting flat spots.

[eightk]

I use a 10”x3” solar panel charger on my 12v lawnmower Battery over winter. The panel is propped up against a north facing window. It starts ok in the spring but I don’t know how well it would work on a car with EV batteries alongside the 12v system.

Also got some Optimate Battery conditioners which work brilliantly on ‘normal’ cars but they need mains power. I’d guess conditioning the 12v Battery would allow the hybrid Battery to be maintained via the 12v system?

Oh, and 4 months avoiding the UK winter. Jealous!

[DaveyBoy]

@dazza1168 The 12v Battery is least of your worry. If it goes flat its cheap to replace. It's the HV Battery I'd worry about. Like Rayaans said, run the car every 2 to 4 weeks for 10 to 20 minutes until the engine trips off would help. But it's best to drive around the block. 

Good luck on your OOA. 

[Herbie]

1 hour ago, DaveyBoy said:

The 12v battery is least of your worry. If it goes flat its cheap to replace. It's the HV battery I'd worry about.

I would think that the HV Battery should be alright for longer than four months.

The 12V Battery boots the computers to start the hybrid system and there's a safety interlock consisting of two 12V relays. If the 12V Battery doesn't have enough power to operate the interlock, the hybrid system is prevented from starting, which means that there's no load for the HV Battery to supply, and so the only drain on it will be its own self-discharge rate.

I may be wrong so if anyone knows better please correct me, but that's how I read it.

[NemesisUK]

2 hours ago, Herbie said:

I may be wrong so if anyone knows better please correct me, but that's how I read it.

According to the maintenance doc I posted above the HV Battery should be recharged every 2 months It also recommends disconnecting the auxiliary battery  -ve terminal if storing for more than 30days. Obviously one would have to reconnect to perform the HV recharge cycle