Is 23-65 kWh at a supercharger normal for a 2015 model S 70D with recently replaced battery pack?

[NLfreesuper90]

A friend of mine was very kind to lend me his 2015 Model S 70D so can see if i want to replace my ICE for a free supercharge Tesla Model S (2016).
His car is 2015 and has 250.000km (150K Mi) on it, but less than 40.000 km (24000mi) the battery pack was replaced (refurbished?) under warranty by Telsa.
The car has free supercharge.

Now comes the problem.

Even after driving to a Tesla Supercharger point (using the route planner) for over an hour, arriving at the supercharger with 34% remaining, the car starts to charge at only 63 kWh.
This very quickly drops to 30 kWh as the battery is at 50%. There were no other cars at the 250 kWh charging point.

If I went to the nearby 120 kWh Supercharger, a 15 minute drive, it starts a 34 kwH, quickly dropping to 23 kWh.

Driving to an non Tesla supercharger makes no difference.

Now the quesiton:
Is this normal? This slow charging speed makes the free supercharger a lot less attractive.

Many thanks for your experiences, remarks and advise.

 

[xAgyex]

This is somewhat expected for older Model S if it is cold outside and the battery is cold. I would recommend to drive the car for at least 30 minutes before getting to a supercharger and even then the rates will still not be great. And also arrive below 20%. Anything else outside of these two windows will result in slower supercharging rates.

Here are some examples of my supercharging rates in my 2014 MS85.

These are from when I was on a road tip, and arrive at each charger with low state of charge, and driving 70 mph on high way for hours.

These are from when I just stopped at my local supercharger after only driving the car for maybe 15 minutes at local speeds.

 

[Rocky_H]

Even after driving to a Tesla Supercharger point (using the route planner) for over an hour, arriving at the supercharger with 34% remaining,

OK, so that should be pretty warmed up on the battery, so I would not expect any issue with cold, as @xAgyex was suggesting.

the car starts to charge at only 63 kWh.
This very quickly drops to 30 kWh as the battery is at 50%. There were no other cars at the 250 kWh charging point.

Charging power is in units of kW, by the way. kWh is quantity of energy.
But yes, this sounds about reasonable.
On those older cars, there were two voltage levels of batteries. There were the larger capacity batteries, like the 85 and 90, which were 400V. And then the smaller ones, like the 60 and 70 were the 350V batteries. Since power is volts times amps, the lower voltage batteries did have a bit lower charging power from Superchargers than the higher voltage batteries did.

My car is a 2014 S85, so it's also an old one like that, but is the higher voltage. People would refer to a rule of thumb of the charging tapering with adding the % and the kW charging power, and it was about 120 when the cars were new. Tesla did later limit some things down some years later, so this number was around 105 to 110. On the 350V batteries, like your S70D, that may have been around 90 to 100. So when you were seeing 63 kW + 34%, that's 97, which seems pretty close to expected.

This slow charging speed makes the free supercharger a lot less attractive.

Most things do have tradeoffs. The newer, improved battery designs have incredibly increased charging speeds. But do you want the unlimited free usage?

 

[brainhouston]

u can always swap in 90/100kwh battery n get faster charging if FUSC is important to u...

 

[kavyboy]

Pretty normal. I have a 2015 S70. My SOC% + charging kW is roughly 100 now (+/- 5). I've driven 1/2 way across the country and although it took longer, it wasn't too terrible. (I had dogs with me, so the stops were going to be a little longer anyway - lots of sniffing!) If you're not planning on doing a lot of road trips where time is crucial, you'll be fine.
You should be aware of what, if anything, is left of the battery warranty, however.

 

[NLfreesuper90]

Thanks for all the replies and comments.

The car nowadays never reaches 120kW. Not even close. The SOC%+kW also does almost never add up to even 100, even when properly pre-conditioned. The one example I mentioned, it maybe starts around 100, but in no time it drops to 80. (50%+30kW). Not pre-conditioned, only gets near 100 at the end: 80%+20kW. But then I've spent already an hour or so hovering arond 23kW.

And all this with a recently refurbished battery.

The car is now back to the rightful owner, with the advise to keep track of the SOC%+kW. I hope to report back in to share some more measurements. In the mean time: any comments are welcome. (Even the ones suggesting to drop in (again!) a new batery!)

 

[kavyboy]

Even the ones suggesting to drop in (again!) a new batery!

It's probably not the best option, but the 100 kWh batteries do reportedly retain their original charging speeds. Of course, Tesla could nerf that in the future.

 

[Rocky_H]

It's probably not the best option, but the 100 kWh batteries do reportedly retain their original charging speeds. Of course, Tesla could nerf that in the future.

It's not just from the battery itself. There were other improvement in the charge port and temperature monitoring by the time the 100 battery came along that also contribute to it keeping up higher charge rates.

 

[bselby01]

I have a 2013 85kwh pack with free unlimited supercharging and randomly screen shot the Tesla app while charging and decided to put into an excel based on percent of charge and charging speed. This is from multiple different supercharging sessions on the original battery that is supposed to have a max charging speed of 120 kw but one time hit 127 kw for a few seconds.