Weird supercharger behaviour

Weird supercharger behaviour

Hello all, long time since I've posted in here. I have a Model S 85 and a Model X 75D. I've been a Tesla owner 5 years now and this just has me puzzled. In the past 3 weeks, I put on 4000 miles on my 75D. Almost all using Superchargers along the I5 between Vancouver, Canada and Los Angeles. I know that the 75D chargers a lot slower than the Long Range/100D but what I'm seeing is weird. I try and get the battery down to about 0-5% while on a trip before charging. At 150kWh stations, I'd plug in and get 125-130kWh at the start and it will taper down to about 30-40kWh within 3 minutes and just stay there. This is with no one else charging at any of the stations. I would then unplug, go over to the opposite (A/B) charger and would get 125-130kWh again and then it would taper down to around 60-70kWh within 3 minutes and lower (40-50kWh) when I hit 50%. It does this at every charger I go to so I'm constantly moving to get the higher charge rate. If I'm sharing a charger, it will start around 30kWh and work up to 65-70kWh and stay there most of the charging which is normal. Some stations, it will go 125kWh and then drop to 0, then jump back up and then back to 0 a few times and then tell me there's a problem. The chargers I use in Canada start off at 125kWh and then drop to 90kWh most of the charging time until I reach about 70-80%. At 72kWh stations, it will remain around 60-72kWh most of the charging time. So I'm actually getting faster charging times at 72kWh stations as compared to 150kWh stations (even when not sharing).

Vawlkus | September 5, 2019

Great, mindgamebracket is another cut and paste spambot. Flagged.

hpjtv | September 8, 2019

ummm what the heck are the previous posts about?

mbirnie51 | September 8, 2019

Hey HPJTV; I travel up and down I-5 from SF Bay to Seattle, and have from 2013 in my MS P85. I traded that in to get a MX 75D in 2017. Recently my 75D has never gone over 80Kw input. I have noted the odometer reading and called Service. If you know your odo readings, they can see whats going on inside the charging circuitry and help you out. I have yet to get mine in for service, but will post once she is fixed.

Note: the MX 75D is designed to accept a maximum input of 96Kw. It is not until you have a 90D that inputs of 125Kw are accepted. What year and month is your build??

hpjtv | September 8, 2019

mbirnie51, I have a September 2017 MX 75D. I only have 30k miles on my vehicle. It was charging fine before this current trip.

jimglas | September 8, 2019

sounds like you need a service apt to evaluate

yabouzaid | September 8, 2019

Hpjtv, i got x75d built October 2018, i got the same thing, i use 90% supercharger , it is 5 min from home after getting back from work, it is starts at 100-125 then drop to 70 and then 40-50, i usually not sharing the charger, i suspect it has to do that i use supercharger every day, but it does better if you like 20% or less and u do the warm up, but still not the same like before , I think this changes happened after battery management software update

NV4NV | September 10, 2019

I am coming up on four years of ownership. I started to get odd supercharge results, as well, and eventually, no supercharging at all. I would switch pedestals, but got zero at each, and no error message. However, I could charge at home normally - just no supercharge, which, of course, practically eliminated long-distance travel. A service visit indicated the need to replace the internal charger, which they did the same day. This seemed odd given that supercharging bypasses the internal charger and at-home charging needs it. Nevertheless, replacement of the internal charger solved the problem. So, with age, older chargers can and do fail, but if still under warranty, you are covered. In fact, I purchased a 2-year extended warranty from Tesla after I crossed 50,000 miles for peace of mind. The internal charger replacement has been the only major repair that I have needed, so by comparison with ICE, I ain't complaining. | September 10, 2019

@NV4NV - Glad you got it solved!

While the actual internal charger is not needed for DC charging, it also has the high-power contactors to allow switching between AC and DC input. Likely one of the contactors for DC operation failed open. These reside in the same module as the AC to DC charger, necessitating the module's replacement.

hpjtv | September 11, 2019

I've put on about 10k miles using superchargers. The remaining 20k (I'm around 30k miles now), has always been at home charging to around 90% and only charging at 24A (I know I can go 48A). Getting tired of having to take this car in to service for every minor thing. Never had so many problems with my Model S and it's nearing 100k miles. I've emailed service and asked them to check my logs, hopefully they get back to me soon. Thanks all.

Bighorn | September 16, 2019

BMS is monitoring many situations that could affect acceptable charge levels. I had some irregular charging in my S that turned out to be a failing coolant pump. There have also been some complaints about the state of some of the PNW chargers not giving full output. Service can remotely diagnosis some of the components in the charging path as well.
Getting down to 0-5% is a bad idea. It was my approach back in 2014 as I was emulating the cross country TSLA team's approach, but not only is it stressful on the cells, it allows no room for error for detours, missed exits, or out of commission chargers.

artc1688 | September 17, 2019

This kinda reminded me how Apple changed the power/battery management to get people to believe their iPhone needs to be replaced. Hope Tesla is not doing this to prevent more owners from charging their Tesla at the SuperCharger station? the slower it charges the car, the fewer people are able to utilize the charging station... hmmm | September 17, 2019

@artc1688 - My understanding is the changes were due to a fire in China during charging. After an investigation, it appears Tesla concluded some older battery packs were charging too fast adding a fire risk and cut the rate slightly.

Bighorn | September 17, 2019

You realize the bulk of their efforts is toward increasing charging speeds, moving up to 250 kW chargers and more capable battery packs?

dkathrina323 | October 16, 2019

I thought that Tesla is a good company. All the reviews are also saying the same thing. But don't know what was happened in your case. Model S 85 and a Model X 75D are Teslas most common models. Just seek help from the Tesla customer service.