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How low can you go?
- Thread starter BuggDDS
- Start date
Good rule of thumb is not much below 20% except on trips or other exceptions. Lit-ion batteries love to be at about 40% to 60% SoC, 70ºF and charged/discharged VERY slowly. The more extremes, the more degradation.......but who can always keep the car in a 70º garage and drive short trips like a granny?
My car came home delivered with 0% SOC. And since they couldn't get the semi down my dirt road in Winter, we met at a rest stop. The driver thought it had a supercharger and I didn't know the car had zero SOC. The driver knew since he loaded it that way in the morning! Loading it back onto the semi to take to another rest stop with a SC, I had to push it, because it was so low on charge, it wouldn't move. Thankfully, it was already on the loading ramp, and I didn't have to push it far.
So, that's as close to empty as you can get. Driving, I've had it down to 7%. My rated range after 14 months is still 310 miles. The battery seems to have survived its near-brick experience.
So, that's as close to empty as you can get. Driving, I've had it down to 7%. My rated range after 14 months is still 310 miles. The battery seems to have survived its near-brick experience.
Kognos
Member
I was in the first few months of owning my M3 SR+ and I was reading the threads about testing the battery charge, and how to reset it's presented maximum charge. The chargers around me were maxed out at 72kw but there was one down the highway that was 150kw. I used the map and navigated to it, and I had % to spare. The idea was to get as low as I could and charge to full, so going a ways out of my comfort zone was good, because I would just burn % to get back home afterward.
So I arrived at the Woodburn Oregon supercharger with somewhere around 6-8% remaining. Thinking to myself "that isn't really a full charge. I want to really get down as low as I can, safely -- at least under 5% -- so I'll just drive to the next exit and circle around"....
Well that was heading southbound on I5. As soon as I passed the highway exit, the car immediately gave me the "drive under 60 to reach your destination" as it rerouted me back to the supercharger. I looked at the map, and it took me a bit too long to realize that it had quite a distance to the next exit ... 8 miles down the road. And then I still had to come back. 16 more miles.
Gulp.
Had I thought about it and been fast I would've just pulled right over and just backed up to the exit I just passed, but no ... the car said it should make it with 1-2% to spare. So I did the next best thing and just turned off everything that used power -- air conditioning, disconnected USB, running lights, anything I could think of. Not much traffic that day so I just set Autopilot in the slow lane and granny-drove at 59 on that 70-mph stretch of highway. It's agonizing sitting there watching the miles run up as you're literally heading away from the charger.... just so I could turn around.
Two things I learned that day:
1. Battery estimates are flexible. Later on I would realize on longer trips that sometimes the "drive under 60..." warnings are based upon the last 5-15 miles of data for you to reach the destination. So if you just drove up a hill for the last 5 miles, it'll overthink your battery consumption and think you probably won't make it, when you will. Trip estimators can be trusted more than the en-route, for this purpose. When I turned off all my stuff, the battery did climb up 1%.
2. Don't try to get to low percentage battery with assumptions like mine. Anything under 10%, play it safe and just run the heater in camp mode or something at the supercharger, if you really want it to run low.
I made it with 1%. It was 2% when I got off the highway and a stones throw away from the charger, so I stopped worrying about consumption of power -- I was creeping along trying to maximize regen while preventing any heavy charge use, until the very end when I raced to the parking spot.
So I arrived at the Woodburn Oregon supercharger with somewhere around 6-8% remaining. Thinking to myself "that isn't really a full charge. I want to really get down as low as I can, safely -- at least under 5% -- so I'll just drive to the next exit and circle around"....
Well that was heading southbound on I5. As soon as I passed the highway exit, the car immediately gave me the "drive under 60 to reach your destination" as it rerouted me back to the supercharger. I looked at the map, and it took me a bit too long to realize that it had quite a distance to the next exit ... 8 miles down the road. And then I still had to come back. 16 more miles.
Gulp.
Had I thought about it and been fast I would've just pulled right over and just backed up to the exit I just passed, but no ... the car said it should make it with 1-2% to spare. So I did the next best thing and just turned off everything that used power -- air conditioning, disconnected USB, running lights, anything I could think of. Not much traffic that day so I just set Autopilot in the slow lane and granny-drove at 59 on that 70-mph stretch of highway. It's agonizing sitting there watching the miles run up as you're literally heading away from the charger.... just so I could turn around.
Two things I learned that day:
1. Battery estimates are flexible. Later on I would realize on longer trips that sometimes the "drive under 60..." warnings are based upon the last 5-15 miles of data for you to reach the destination. So if you just drove up a hill for the last 5 miles, it'll overthink your battery consumption and think you probably won't make it, when you will. Trip estimators can be trusted more than the en-route, for this purpose. When I turned off all my stuff, the battery did climb up 1%.
2. Don't try to get to low percentage battery with assumptions like mine. Anything under 10%, play it safe and just run the heater in camp mode or something at the supercharger, if you really want it to run low.
I made it with 1%. It was 2% when I got off the highway and a stones throw away from the charger, so I stopped worrying about consumption of power -- I was creeping along trying to maximize regen while preventing any heavy charge use, until the very end when I raced to the parking spot.
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