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Battery Versions

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Pruitt

Pontificating the obvious
Jun 27, 2014
554
704
Casper WY
This is probably on this forum somewhere, but I sure can't find it, so...

Can anybody explain what the differences are between the "A", "B", "C", and so on battery versions?
How many different versions are there? I've seen references to "D", but that's it.
Does Tesla make these distinctions, or are they categorized by the owner community, or...?
When my Model S arrived in a few months, how do I tell what version I got?

Thanks!
 
Brunton, just in case that wasn't clear, the 90kW number refers to Supercharging power transfer rate, not to the capacity of the battery in the car.

Your S will come with whatever the latest battery type is when your car is built. Currently that appears to be the D type.

These distinctions are shown on the factory sticker on the pack, and have been adopted by this community. Tesla has never made an official statement about the different batteries as far as I know.

I think no one has reported having a C type. A is the earliest, then B, then D. The difference between B and D is unclear. Of course Tesla knows but they aren't telling. ;-)
 
(LMB spouse)

Also, the A/B/D discussion is mostly about the 85 kWh packs. The 60 kWh packs have similar numbers, but the A/B/D versions of the 60 behave differently than the 85. I believe that all 60 kWh packs max charge at 7/8 of 120 kilowatts, i.e. 105 kW +/-. I'm sure someone will correct me if I'm wrong. :)
 
Brunton, just in case that wasn't clear, the 90kW number refers to Supercharging power transfer rate, not to the capacity of the battery in the car.

There seems to be a lot of confusion when it comes to units in this area of discussion. For purposes of a Tesla, power is measured in kiloWatts or kW. Energy is power multiplied by time; in the Tesla we measure energy in Watt-hours (W-hr or Wh) or kiloWatt-hours (kW-hr or kWh, 1,000 Wh = 1 kWh). A 50 kW charge rate for 1.5 hours transfers 75 kW-hr of energy. The energy capacity in batteries delivered in the Model S today are either 60 kWh or 85 kWh. A current production 60 kWh battery when near zero state of charge can accept a charge rate (power) of up to 105 kW, and an 85 kWh battery can accept a charge rate (power) of 120 kW. Hot or cold batteries have a reduced charge rate and older, "A", 85-kWh batteries can only accept a maximum charge rate of 90 kW of power.

Remember kW measures power, battery charge rate, or motor power, and kWh measures energy or battery capacity.

Unit Trivia:
  1. Watt is always capitalized because it is named after James Watt, who deserves our respect.
  2. A Watt is the basic unit of power and is a Joule per second.
  3. A Joule is the basic unit of energy and is a Newton-meter. The Joule is named after James Prescott Joule.
  4. A Newton the basic unit of force and is a kg-m/s^2. The Newton is named for Sir Isaac Newton.
 
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There seems to be a lot of confusion when it comes to units in this area of discussion. For purposes of a Tesla, power is measured in kiloWatts or kW. Energy is power multiplied by time; in the Tesla we measure energy in Watt-hours (W-hr or Wh) or kiloWatt-hours (kW-hr or kWh, 1,000 Wh = 1 kWh). A 50 kW charge rate for 1.5 hours transfers 75 kW-hr of energy. The energy capacity in batteries delivered in the Model S today are either 60 kWh or 85 kWh. A current production 60 kWh battery when near zero state of charge can accept a charge rate (power) of up to 105 kW, and an 85 kWh battery can accept a charge rate (power) of 120 kW. Hot or cold batteries have a reduced charge rate and older, "A", 85-kWh batteries can only accept a maximum charge or 90 kW.

Remember kW measures power, battery charge rate, or motor power, and kWh measures energy or battery capacity.

Unit Trivia:
  1. Watt is always capitalized because it is named after James Watt, who deserves our respect.
  2. A Watt is the basic unit of power and is a Joule per second.
  3. A Joule is the basic unit of energy and is a Newton-meter. The Joule is named after James Prescott Joule.
  4. A Newton the basic unit of force and is a kg-m/s^2. The Newton is named for Sir Isaac Newton.

"Unit Trivia" :biggrin: I can't resist trivia of any kind. My mind is filled with endless factoids. Now if only I could remember what I had for lunch!
 
(LMB spouse)

Also, the A/B/D discussion is mostly about the 85 kWh packs. The 60 kWh packs have similar numbers, but the A/B/D versions of the 60 behave differently than the 85. I believe that all 60 kWh packs max charge at 7/8 of 120 kilowatts, i.e. 105 kW +/-. I'm sure someone will correct me if I'm wrong. :)

Yes. When people say "A" vs. "B" vs. "D", they are referring to Tesla's part number format, XXXXXX-YY-Z, where XXXXXX is the part identification, YY seems to be a supplier (not confirmed), and Z is the specific part revision. Z is only applicable to XXXXXX. So in some cases, the revision of refurbished battery packs - which have a different part number from new packs - may be different.
 
(LMB spouse)

Also, the A/B/D discussion is mostly about the 85 kWh packs. The 60 kWh packs have similar numbers, but the A/B/D versions of the 60 behave differently than the 85. I believe that all 60 kWh packs max charge at 7/8 of 120 kilowatts, i.e. 105 kW +/-. I'm sure someone will correct me if I'm wrong. :)

I'll take you up on that. There was a report of a 60 kW B pack car charging at 111 kW. The battery revision number on S60s is different than those on S85s.

Separately, if we scale the C rate of the cells from what we know about the S60 we see that an S85 B pack is capable of ~150 kW max charge rate.
 
I'll take you up on that. There was a report of a 60 kW B pack car charging at 111 kW. The battery revision number on S60s is different than those on S85s.

Separately, if we scale the C rate of the cells from what we know about the S60 we see that an S85 B pack is capable of ~150 kW max charge rate.

At some point, I think that Tesla may be running into current limits for the wires and relay inside the car. The 120 kW max charge rate also seems to be limited to 333 Amps. Given that a mostly discharged 85 kWh battery is approximately 360 Volts, that 333 Amp limit is also approximately a 120 kW limit. I am sure that Tesla has a maximum current for the wiring inside the car. Is it 333 Amps? I don't know, but remember that the heat into the wiring from resistive heating goes up as the current squared (I^2). As batteries improve, it may be the wiring that is the ultimate charging limit...
 
Thanks everyone! That really cleared it up for me!! :-D:-D

I also found this quick review helpful.

Are there any Superchargers in California or elsewhere on the West Coast that allow for greater than 120kW charging?

I just recently went from a B to a D pack (second high voltage battery failure/replacement) and still only saw up to about 118 kW as the max charge rate at a couple of the California Superchargers this past weekend (Hawthorne, Tejon, Harris Ranch and Gilroy).
 
There are 135kW superchargers out in the wild, but I am not aware of any credible data that a single car can access much more than 120kW. The extra capacity helps with the 2-cars-sharing-one-supercharger situation, that's all.

Does anyone have hard data of someone charging at significantly greater than 120kW?
 
There are 135kW superchargers out in the wild, but I am not aware of any credible data that a single car can access much more than 120kW. The extra capacity helps with the 2-cars-sharing-one-supercharger situation, that's all.

Does anyone have hard data of someone charging at significantly greater than 120kW?

Ahh. that makes sense. Very helpful. Thank you.

During some of my stops this weekend, the superchargers were full or close to full and assuming that some or all of these SC are 135kW, in those situations, I must have benefitted from the extra charging capacity of the 135 kW SC. Thanks again.

By the way, when you get a taste of 118 kW, it's a bit disappointing to have to share. So spoiled.
 
Unfortunately other than A/B differences there's not much out there. Haven't heard of anyone with a C pack and D seems to be equivalent to B.

1. I don't believe the C pack ever made it to production, or if it did, none of the purchasers joined TMC.

2. We don't know if the 135 kW chargers give full charging with a B pack (at least I haven't read any posts one way or the other). It might be that the B packs are limited to 120 kW (only speculation).
 
2. We don't know if the 135 kW chargers give full charging with a B pack (at least I haven't read any posts one way or the other). It might be that the B packs are limited to 120 kW (only speculation).

Well, the cells themselves can handle up to 150 kW. This is derived from the scaling up the max C rate from the S60 pack, which is made from the same cells. Whether there is another limitation though is anyone's guess.
 
Right, I was thinking of a software limitation.

Or perhaps, the 333 Amp limit that goes with the 120 kW limit is as much current as the wires in the car will carry. By the NEC, with the best, high-temperature insulation, it takes 350 mcm copper to support a continuos current of 350 Amps. 350 mcm wire is the equivalent of 6/0 copper wire; that's big. Tesla does not have to follow the NEC and tends to push a little harder, but half the copper of the NEC to support 350 Amps is still a 3/0 cable; that's fat!
 
If new packs would need less tapering, I guess it would make charging faster more effectively than small increase in peak charge rate. It would of course also be better in that sense, that amp limit would not be problem.