Leaving car untouched for several months

[Tonybvi]

We are very fortunate in that being retired we can take off in our motorhome (diesel I’m afraid!) for several months each year to enjoy warmer climes. We are also lucky enough to be able to leave our EV (Tesla Raven MX) in a garage plugged into a charger while we’re away. However I would like to get your opinion on the best charging strategy for several months of absence. Do I schedule a start time each day so that it simply wakes up and charges itself to the set limit once every 24 hours or do I have no scheduled start time and let itself wake up, check the charge state, and charge itself whenever it feels it needs a top up? Also what would you recommend as the charge limit?
Any polite suggestions would be much appreciated, thanks.
Tony

 

[Avendit]

Not surprised you try to escape the NE! bad enough down in Edinburgh already :/

For the X, I believe the advice will be to leave it plugged in and let it manage its self. I'm sure the official would be set to 90% and leave it, but I'd probably pick a number closer to the middle of the range as being the least strain on the battery.

I'd also be really tempted to log a call with tesla and ask, as you are pretty out there as a corner case. They might recommend something weirder. I have an email address for someone at Edinburgh I can message you if you need.

Or you could drop it off at mine? I'll, ahem, look after it. Let it snuggle up with my 3. Keep it charged, let it stretch its wheels now and again...

 

[Cwmwd]

Let it do it's own thing but maybe drop the current to it's minimum & set limit to 50/60% so you get more of a trickle charge. Also, give a neighbour or friend a run down on how it works and the spare key?

As suggested by @Avendit giving Tesla a call would be the best rather than trusting your X to the "wisdom of crowds"!

If Tesla suggest a scheduled charge maybe set a schedule for a time convenient for the timezone you'll be in so it's awake when you are (just in case).

 

[TezzyMod3]

Why not just leave it unplugged and let it run out of charge?
That way nobody can steal it in a hurry either whilst you’re away

 

[Mark_T]

I also have to spend a while away from my car at times, not as long as the OP but long enough...

I used to leave it plugged in to sort itself out, but after a while it would throw up a warning message that frequent very small charges were not recommended.

So I changed my strategy to charge the car to 90%, then set the charge limit 50% and let the car slowly discharge until it got down to around 55% or before changing the charge limit back up to 90% and repeating the exercise as needed.

 

[eladts]

Why not just leave it unplugged and let it run out of charge?
That way nobody can steal it in a hurry either whilst you’re away

Letting the battery run out is not a good idea. First, if the main battery runs out the 12V battery will run out too and you will need to jump start it to even open the doors. More importantly, leaving the battery at low charge for an extended period of time is not recommended.

 

[WannabeOwner]

Do I schedule a start time each day so that it simply wakes up and charges itself to the set limit once every 24 hours

That's what I have done. It will charge if it has fallen far enough to need to. I just leave the normal "Off Peak" charging schedule.

I also leave it charges to e.g. 80-90%, as normal, but then set LIMIT to 50% so that once it falls to there it stays around that amount. I think battery management in Tesla is so good, and there has been enough anecdotal evidence of Airport Taxis being thoroughly abused on rapid charging / left at 10)% for prolonged periods, and still having only modest degradation at 100-200,000 miles ... but its easy enough to set to 50% when leaving for prolonged period, so might as well.

I would also want an Alert if it fell to, say, 40% (TeslaFi scheduler, for example, can do that) so I could get a neighbour to go and sort out a tripped circuit / whatever.

 

[elecTED]

@Tonybvi

The official Tesla position is you should never leave a Tesla alone for several months in a row. It will feel very lonely and unloved. Tesla recommend you leave the car in the company of another Tesla, preferably a M3 SR+ MSM in slightly warmer climates down south with a VIN ending in 0204.

There’s one car that fits that bill and I think it belongs to @elecTED

 

[.jg.]

The only reason I could see for using scheduled charging would be if you get cheaper rates at certain times of the day. Otherwise, I would just let the car decide when to charge, which is what the owner's manual recommends.

 

[adsheff]

Lend it to a friend so it can have some use!

 

[KennethS]

All these people suggesting leave it with a friend to give the car some use, how does insurance work when lending out your car?

 

[TSLA Pilot]

IIRC from various detailed sources (such as Li-ion battery researchers), the optimal situation is to leave it plugged in and set to charge to 50% SOC.

This should result in near zero battery degradation over many years of storage.

I'd post the links but I can't recall them exactly, but this is some of the info from one of the premier searchers in this area of materials science:

About

 

[GSP]

@Tonybvi,

I would set the charge level to 50%. That is best for long term battery storage.

The car will wake up and charge as needed. If you have off-peak electrical rates just leave scheduled charging at your normal time.

Enjoy your winter!

GSP

 

[mick4545]

Mine can sit for a week or so without use, my charging regime is to leave it plugged in, set to 50%. When planning a trip I estimate the juice required then charge that amount either side of 50%. For example if I estimate I need 40% for the trip, I'll charge to 70% just prior to leaving, arrive back at 30% then leave it to top off to 50% again.