Do we have a firm idea on when the battery balances? Some say 90%. Some say 85%. Fewer say 80%. Some say 4.00V/cell. But the thing is, my car (via SMT) shows 4.00V/cell far before 85%. I can't recall exactly, but I'm betting it's somewhere between 70%-80%. Which would imply we don't need to be charging as high as 90% just to balance the packs.
I recently had a sudden drop that's probably just the BMS catching up to real degradation finally. Funny thing is I saw this with the percent display instead of range - my percentage jumped up 2% overnight, and confirmed this was a change in capacity via SMT rather than some temperature variable or something. Had I been displaying range, I would know this without SMT which is... kinda nice?
Hey, I know it's been a bit since you posted this. Wanted to say sorry for all the misleading or lacking statements on range you encountered prior to getting your car. Tesla is responsible for this, and as a very hyped community we often are too optimistic.
Teslas lose range in the same conditions gas vehicles do, but you've probably never noticed it that much. Where it tends to vary a lot (e.g. highway travel), you're just stopping at gas stations as necessary in ICE because they're plentiful. With the reduced range capability of an EV, you now have to be very aware. Anyone who says otherwise likely has a good EV charging network nearby (I don't and didn't even after travelling 2500km into the US).
- Rain hurts range a lot, but what hurts way more is being in the rain grooves. Try to rid atop the higher spots so that you're not pushing so much water out of the way.
- Supercharging is slower than you'd expect because you're probably charging all the way. The last 30% is especially slow. Working with the lower part of the battery (0-70%) will give you faster charging, but is of course riskier in terms of being stranded. You can pick fast charging or a comfortable range buffer, not both. Using abetterrouteplanner.com will give you a more time-optimised route in the future (stops at more chargers, but uses the lower portion of the battery for faster charging).
- Cold is super detrimental. You often can't just not heat the car in those conditions (turns out you need to be able to see the road and feel your hands to drive), but the heater takes a lot of power. Expect 30-40% reduced range normally in cold, more if it's really cold or snow/rain exists. A Model Y will do better since it uses a heat pump, not a resistive heater.
- The range display is "rated range", so in cold you will indeed burn through rated miles faster than actual miles travelled. Rated miles are actually a sort of energy unit (because it's rated for so many Wh/mi). If you use energy faster than rated, it will show. So yes, perfectly normal.
- Wheels do impact range, but you do you. I wanted them as well but the Aeros grew on me, plus we highway travel a lot.
- Lights & wipers don't really consume significant amounts of energy. I know Tesla recommends turning off lights, but they're really not significant at all and you need the lights. Turning off the AP computer would technically net similar results, but they don't let us do that!
I think you're right to think about range all the time, honestly. A 56mi round trip every day in the worst conditions consumes something like 110 rated miles. You only have 250 to work with, but you're probably only using 80% of your battery on a daily basis at most (keeping between 10%-90%), which is only 200 miles of rated range to work with.
Now you know. This is the EV lifestyle. This isn't a situation unique to Tesla (though those do exist). Well... the heating being so expensive is a bit more of a Tesla problem than some other popular EVs, but it's not unique to Tesla.
Voltage sag would mean reading a lower voltage at higher SoC (remaining capacity) though - if anything, 85% @ 4.00V seems to indicate that's the reference with sag based on my car? Which is why I'm not sure these statements are really accurate?
Right now, ~45 minutes after a drive, it's showing a minimum of 4.10V at 86.6% SoC at a fairly reasonable 26C. Even if I inflate the percentage by not accounting for the bottom end buffer, that's about 87.2%. I hate to say "the service manual is wrong", especially given that I'm using third-party tools to get this information and can't hold Tesla to it at all , but it certainly seems to have contradictory numbers. Anyhow, it seems that the 4.0V is the important part since the 85% SoC is in brackets, and perhaps was just an honest mistake or rough head calculation. If so, at least based on my car, then it seems we don't need to charge beyond 85% (probably lower, will need to report back) in order for it to start balancing. I definitely saw greater imbalance numbers when I was charging to 60-70% but never when I charged to 80%, so there might be something here.
What about everyone else? If you often charge to 80% for example, what voltages are you getting at 80%?
Hey, no problemo. I sympathize a lot with the "not an electrical engineer or a fanboy" folks - if EVs are going to become common, then it's not just EE's and fanboys going to be driving them, and it's gotta work for them too!
RIGHT! Thank you so much!!!