Self Discharge of EV Batteries - Your Experiences?

[wolverine86]

I have long wondered what the real life self discharge rate of EV batteries is. I realize that it probably varies due to outside temperature and maybe even outside humidity, but what are your real life experiences? How much range do you lose if your vehicle is just sitting around without being charged, not being driven for a week or even a month? Or to put it another way, say you go on a trip for work or pleasure and drive your EV to the airport and leave it in the parking lot for a couple of weeks and you have 150 miles of range when you park it. What would it be after the couple of weeks? 140 miles, 120 miles, or what?

Note that I'm not asking about how much lifespan you have of your EV batteries before they need to be replaced, just how long do they hold a charge assuming that they are in good condition and how much does an EV's range get reduced over time by sitting around doing nothing.

I have no experience whatsoever owning an electric vehicle (not even an E-bike or a golf cart!), so hence the questions! I have only owned ICE vehicles and human powered vehicles (i.e., bicycles!). I do have experience with Li-ion battery powered tools, and these definitely do lose charge noticeably over a month or more. But auto EV batteries typically have much higher voltage and current capacity than those.

 

[wolverine86]

Sorry, I guess I should have posted this in the Electric Vehicles forum. I'll make a post there. Moderators, please delete this thread if you like!

 

[Nick1994]

I’m sure it depends on the electric vehicle and what settings are chosen.

Tesla will run the HVAC to keep the inside from getting too hot to protect the electronics. In Phoenix sitting in the sun, it won’t last as long as in the PNW.

 

[97prizm]

I think there is info out there. Many a Tesla and other owners have mentioned that setting at airports for an extended period can make them go dead.

 

[GrumpyCat]

A Tesla will run cooling fans, or heater, if left out in extreme weather. Also has Sentry Mode to video suspicious activity. If enabled, Sentry Mode can drain many miles of range/day. As can “cabin protection” which keeps interior cooler than 100°F.

Never left my Model S sitting more than a week off-power. Cabin protection off, I my old car didn’t have Sentry Mode. Lost about 15 miles of range.

So there is some cost in keeping the car online when parked (that it can reply to the phone app). And other options that one should reasonably be willing to share power for their benefits. Can’t expect something for nothing.

 

[StillLearning]

A coworker with a Model 3 standard range left his car at the airport parking lot while traveling for a little over a week. The car had just over 80% charge when parked. Upon his return the car was down to about 15% charge and he had to stop on his way home to charge. He was not all too happy.

I don't "Tesla" so not sure what settings he had selected when parked and didnt think to ask. This was last winter in CT.

With whatever settings he had selected he would have to charge the car weekly even if he was only driving it 20 miles a week.

 

[andrew_j]

A coworker with a Model 3 standard range left his car at the airport parking lot while traveling for a little over a week. The car had just over 80% charge when parked. Upon his return the car was down to about 15% charge and he had to stop on his way home to charge. He was not all too happy.

I don't "Tesla" so not sure what settings he had selected when parked and didnt think to ask. This was last winter in CT.

With whatever settings he had selected he would have to charge the car weekly even if he was only driving it 20 miles a week.

Something is amiss . Maybe your friend forgot initial charge level:

https://www.tesla.com/support/range#:~:text=It%20is%20expected%20for%20a,notice%20that%20consumption%20is%20higher.

7%/week is sooooo far from your friends stated 65% loss/week.

 

[Nick1994]

A coworker with a Model 3 standard range left his car at the airport parking lot while traveling for a little over a week. The car had just over 80% charge when parked. Upon his return the car was down to about 15% charge and he had to stop on his way home to charge. He was not all too happy.

I don't "Tesla" so not sure what settings he had selected when parked and didnt think to ask. This was last winter in CT.

With whatever settings he had selected he would have to charge the car weekly even if he was only driving it 20 miles a week.

He probably left Sentry mode on and interior comfort. A big no no when parking a Tesla for an extended period of time