90D Rated Range

[apacheguy]

Yes, I want to be very clear that the data I show is what the car thinks is available when it displays "rated range". It's not intended to address how much you can actually get out of the battery, or anything else.

Mostly, I publish it because there are people who are relying upon the "rated range" display when considering "battery degradation", and if you are calculating degradation based on a high-water mark observed in May and a low-water mark observed in January, you're going to believe you have more degradation than expected.

I will be posting my data probably later this month. It seems that some later software releases have changed the algorithm (or something happened with my battery), as the rated range on my car has been impacted, aligned with the date of the software updates for 7.1.

I'll update the thread within a month or so.

Can you see on the CAN logger if the battery energy has been influenced as well as rated range? Mine has stayed consistent across firmwares since I began monitoring (75.5 - 76). Also, I haven't gone above 90 in several months and my cells are still very well balanced (4-6 mV)

 

[FlasherZ]

Can you see on the CAN logger if the battery energy has been influenced as well as rated range? Mine has stayed consistent across firmwares since I began monitoring (75.5 - 76). Also, I haven't gone above 90 in several months and my cells are still very well balanced (4-6 mV)

No changes, but my first CAN scan occurred after the new releases so I can't compare w/ last year. No major changes since my last reading.

 

[David99]

Yes, agree. What you describe (fully discharge then full charge) is what I (and Tesla) calls balancing the pack and not doing it will cause loss of rated miles per my post upthread so I think we are saying the same thing but using different terminology. The algo gets out of sync. What do you call it?

I'd say balancing in context with batteries means individual cells get charged or discharged slightly less or more or experience different temperatures and as a result a difference in charge level occurs. What happens in our cars is the just a limitation in accuracy. Like a calibration issue.

 

[FL600]

12/15 90D. 235mi at 90%. Haven’t charged to 100% yet. I might drive it close to zero then charge to 100%. Very disappointing to say the least. If this is accurate, the battery has degraded by 10% with only 32k miles on the vehicle.

 

[gsteele]

12/15 90D. 235mi at 90%. Haven’t charged to 100% yet. I might drive it close to zero then charge to 100%. Very disappointing to say the least. If this is accurate, the battery has degraded by 10% with only 32k miles on the vehicle.

It’s probably not accurate. You probably need a deep discharge, full recharge cycle to recalibrate it.

 

[FL600]

It’s probably not accurate. You probably need a deep discharge, full recharge cycle to recalibrate it.

So I ran it down to 18% and then charged it to 100%. That gave me a total of 262 mi. I thought it would have showed more. That’s right at 10% degradation which seems like quite a bit for it having low miles and 3.5 years old.

 

[No2DinosaurFuel]

So I ran it down to 18% and then charged it to 100%. That gave me a total of 262 mi. I thought it would have showed more. That’s right at 10% degradation which seems like quite a bit for it having low miles and 3.5 years old.

I calculate a 8.4% degradation.

Your 90d originally had a 286 miles at 100%. The new fascia model S revised the miles at 100% to 294 miles.

This is typical IMO for the age of the battery.

 

[amallah]

I assume it's some combination of battery degradation and firmware logic. TeslaFi has a cool feature which records a data point every time you charge and then graphs it. It just looks like degradation over time to me. My 90D is set to charge to 90% daily (except when I'm planning a super long road trip the next day), so it's not like I've been hard on the battery.