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I kinda wish my EV would just set the apparent 0% and 100% points at a level that guaranteed X cycles, where X corresponds to perhaps 200K miles. As capacity a

I kinda wish my EV would just set the apparent 0% and 100% points at a level that guaranteed X cycles, where X corresponds to perhaps 200K miles. As capacity and fast charging infrastructure improves, it'll be less important for me to access the top 20% of the battery just to make a road trip feasible. Hell, I'm okay with it just being a lie that I can control. Let me choose those points.

seanmcdirmid 3y ago
I find it a lot easier to keep my EV between 20 and 80% than my cell phone. Just plug in whenever you come home and set your top charge to 80%.
magicalhippo 3y ago
BMW i3 does that, kinda. I checked the raw data against the claimed battery size, and the in-car 0-100% was 20-80% of the battery. My new Renault Megane E-tech does not do this. Instead it has an option to limit charging to a given percentage (if you set it to 100% it'll ask if it's just next charge) and the manual states that if you have less than 15km range the car might switch off at any moment without notice... Let's just say I was mildly surprised about the latter. Both cars had battery guarantees though, the Megane's is minimum 80% SOH after 8 years or 160000 km, with no reservations against charging to 100%.
Reason077 3y ago
> ”I kinda wish my EV would just set the apparent 0% and 100% points at a level that guaranteed X cycles, where X corresponds to perhaps 200K miles.” They already do! In most EVs, 0% is not really zero: you can typically drive another 20-40 miles before it finally dies. Most EVs will easily have a battery life of 200K miles, with some capacity degradation. Active battery management such as limiting the max charge is more about preserving the battery life beyond this, and reducing degradation. And all of this becomes less necessary with LFP battery chemistry, which is leas fussy about charge levels and less susceptible to degradation.
- Gigachad 3y ago
  What happens if you actually do fully drain an EV on the road? How do you recover from that situation? Normally you’d just have to get a container of fuel delivered to you.
  - Reason077 3y ago
    Most likely you get towed to the nearest charger on a flat-bed truck. But portable chargers (with batteries or diesel generators) on the back of trucks or vans also exist. Some EVs also support power output (V2x) from their charge ports, allowing you to charge up one vehicle from another.
    - numpad0 3y ago
      What exactly is the reason the car shouldn't be towed for regen? It seems a dead EV can just be towed to the midpoint between origin and the nearest charging station, then can be driven to the station using regen'd charge.
      - Reason077 3y ago
        If the EV is truly dead then you may not even be able to put it in Drive mode until it’s plugged in, so regen wouldn’t be possible. But sure, assuming you have enough power to put it in drive, there’s no reason that you can’t do this. There’s YouTube videos where people have tried it successfully. My understanding is that manufacturers don’t support or recommend this method, though.

seanmcdirmid 3y ago

I find it a lot easier to keep my EV between 20 and 80% than my cell phone. Just plug in whenever you come home and set your top charge to 80%.

magicalhippo 3y ago

BMW i3 does that, kinda. I checked the raw data against the claimed battery size, and the in-car 0-100% was 20-80% of the battery. My new Renault Megane E-tech does not do this. Instead it has an option to limit charging to a given percentage (if you set it to 100% it'll ask if it's just next charge) and the manual states that if you have less than 15km range the car might switch off at any moment without notice... Let's just say I was mildly surprised about the latter. Both cars had battery guarantees though, the Megane's is minimum 80% SOH after 8 years or 160000 km, with no reservations against charging to 100%.

Reason077 3y ago

> ”I kinda wish my EV would just set the apparent 0% and 100% points at a level that guaranteed X cycles, where X corresponds to perhaps 200K miles.” They already do! In most EVs, 0% is not really zero: you can typically drive another 20-40 miles before it finally dies. Most EVs will easily have a battery life of 200K miles, with some capacity degradation. Active battery management such as limiting the max charge is more about preserving the battery life beyond this, and reducing degradation. And all of this becomes less necessary with LFP battery chemistry, which is leas fussy about charge levels and less susceptible to degradation.

Gigachad 3y ago
What happens if you actually do fully drain an EV on the road? How do you recover from that situation? Normally you’d just have to get a container of fuel delivered to you.
- Reason077 3y ago
  Most likely you get towed to the nearest charger on a flat-bed truck. But portable chargers (with batteries or diesel generators) on the back of trucks or vans also exist. Some EVs also support power output (V2x) from their charge ports, allowing you to charge up one vehicle from another.
  - numpad0 3y ago
    What exactly is the reason the car shouldn't be towed for regen? It seems a dead EV can just be towed to the midpoint between origin and the nearest charging station, then can be driven to the station using regen'd charge.
    - Reason077 3y ago
      If the EV is truly dead then you may not even be able to put it in Drive mode until it’s plugged in, so regen wouldn’t be possible. But sure, assuming you have enough power to put it in drive, there’s no reason that you can’t do this. There’s YouTube videos where people have tried it successfully. My understanding is that manufacturers don’t support or recommend this method, though.