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Home Charge Rate Halved

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#21
Same again last night. Tried several short charges in the early morning. Initially only 16amps. After unplugging and replugging - 32amp charge. Stopped charge, made another unplug/replug and charge current selector showed 21amps! Started a charge at 21amps but was able to raise to 32amps. Stopped charge. Unplugged/replugged. Set timer for 15 minutes ahead. on the timed charge it only charged at 16amps. I've also tried my 240 volt Tesla UMC charger. That shows a charge at 10amps/2kW max. I think it should charge at 13amps/3kW.

I rang Tesla who couldn't find any solution looking at the logs and advised a service/ranger visit. I think I'll try connecting to another 7kW charger before I start incurring costs with Tesla, in case it is my home wiring causing the problem. I guess since it will charge at 32amps it's not one of the internal charger fuses blown.
 
#25
I’m now fairly convinced that it’s a software problem and it's connected with Scheduled charging if not unplugged in between charges. Here’s what I tried:

With 32amps showing on the current selector (unplug and replug if 16amps max showing) - set next scheduled charge for the next available interval - 15 mins ahead. Starts on schedule and charges at 32amps.
Now stop the charge, DON’T unplug or touch anything else, but reset to the next scheduled charge interval (+15 mins). This time it starts on schedule, momentarily shows 1amp, then drops back to zero and the currect selector resets to 16amps, max available, then it restarts charging at only 16amps.

Stop charge, unplug/replug - the current selector changes to 32amps and a full 32 amp charge is available either on the next scheduled charge or immediately non-scheduled.

I tried raising the charge % to 100% in case a small charge was causing a restriction, but still only 16amps available. I also tried setting a “Depart At” time so that the set charge % could be achieved at 32amps but not at 16amps. No joy, it immedaitely started at 16amps and would not have achieved the departure set %.

Rather wierd - is this a bug, or some deliberately programmed behaviour to reduce charge load when the car has been sitting idle for a day or more? I’ve just read the bit about charging in the manual but can’t find anything to suggest that.

I also tried tests NOT using the scheduler, but starting the charge manually, either on the screen or the App. As long as it ws unplugged and reconnected before the first test, it happily charged at 32amps when started at intervals of 15, 30 and 60 minutes and then stopped once charging at 32amps. It rises to 16amps, holds for a few seconds and then rises to 32amps.

Having unplugged and reconnected it yesterday I set the scheduler for 3.00am as usual and this morning it had charged at 32amps. I have not touched anything except to raise the target charge a few percent. I would put money on it that it will now charge tonight at 16amps.

I'm going to take the car round to a friend with Telsa chargers this weekend and see if the behaviour repeats itself.
 
#26
Yes, it did charge at 16amps last night. But today we tried it out on my Friend's Tesla wall charger and it behaved perfectly. 3 scheduled charges started and charged at 32amps. I note that the first occurrence, according to TeslaFi, was 2.00am on 21st March and update 2020.8.1.1 installed on 20 March at 23:30, which is a bit suspicious.

However, today we tried it out on my Friend's Tesla wall charger and it behaved perfectly. 3 scheduled charges at 15 minute intervals started and charged at 32amps. That suggests it's not the car, and we already tried a different Mennekes cable. So it points to the Rolec charger itself, although I'll try disconnecting the in line EV meter ,that transmits data to the government's data collectors, in case there could be a problem there. I've head that a lot of the wall chargers tend to have a limited life and were not designed to handle the continuous 7kW charge that Tesla's can pull, including some early public chargers, which tended to fail after a Model S had charged for 20 minutes. 32amp RCBO's can develop fatigue when used continuously at full rated capacity and the same probably goes for the internal contactor. The Tesla charger is apparently much better constructed.
 
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#27
I’m continuing to have exactly the same issue as you, my Rolex wall charger always charged at 32 amps (replaced dodgy components but that’s another story). But the last couple of months it has started charging at 16 amps but only when scheduled charge (00:30hrs).

If I plug charge cable in manually without scheduling it charges at 32amps. So I thought it must be my Rolex wall charger and bought a brand new smart Ohme charger...

nope, 3 weeks in and it’s still behaving badly charging at 16 amps every night. The charger is clearly set to 32 amps and I’ve even set the Model S to 20 amps to see if it was the charger or car.

have been speaking to Tesla engineers about this, only way is to book it in for a service then they start communicating with you properly about the issue.

They want me to manually charge at 00:30hrs tonight to show the log it charging at 32 amps. Really need this fixed as I spent £ on that new charger when now I am really thinking it is the car since recent updates.

I’ll post my discussions on here when done.
UK based
 
#28
So I'm not the only one - Interesting! I did a shopping trip yesterday and when I returned, a short test charge achieved 32amps. I unplugged and re-plugged it and set it to do a scheduled charge last night and it only charged at 16amps. So it's not consistent. I'm borrowing a Juice Booster for the weekend. That charges up to 32amps, so I'll be able to find out whether it's the charger.

Since I'm not doing much mileage at the moment and I can force it to charge at 32amps if I need to, I'm not inclined to book the car in at the moment. I can wait for a while, hopefully until Gatwick reopens... I live in hooes but that may be put back due to the lockdown I guess. If you get Tesla to investigate, do let us know the outcome, Spacey73. If it's software,other people may be affected and not realise at the moment if they are doing scheduled charges at night and not driving much due to lockdown.
 
#30
Spacey73 - did you get anywhere with Tesla on the 16amp charging issue? Getting sensible answers out of the online booking system is next to impossible, but after a lot of badgering they sent me an estimate of £2500 for a replacement Gen 2 charger! Since the existing setup is charging at 32amps when prompted I hope this is just a worst case scenario, I can't get any answers about what the initial assessment by engineering from my description and the logs showed. I don't intend to write Tesla a blank cheque, I want to know why they would replace a charger that is working normally but there seems to have a scheduled charge programming issue. I read somewhere that they charge for a replacement charger if just the fuse has blown - a cheap job to replace but a bit of a game disconnecting cooling pipes etc. It's clearly not the fuse in this case as it will charge normally when forced to.
 
#31
The reduced charging rate seems to have almost cured itself now! Most, but not quite all scheduled charges are now charging at the full 32amps - Really weird. Glad I didn't unnecessarily spend £2.5K on the new charger Tesla Service indicated was required! Going in to Brooklands tomorrow for a replacement 12v battery. £188 quoted, that sounds quite reasonable, rather less than I expected. Organising the service via the app was another story, screwed up by an ios 13 bug in notifications, and lac of response to my texts from Tesla - as I have reluctantly come to expect - but that's another story. Hope Spacex don't rely on Apple products, or Microsoft for that matter.
 
#32
I am wondering if your recent arrival or properly working charging is somehow related to grid voltage stability? We are coming out of the main air conditioning season, but your in the UK, so I don't know how that looks there.
 
#34
The Tesla cars pay close attention to voltage stability because the software doesn't want to burn stuff down. Plenty of people have had issues when the car detects issues even if they are external to the house. The car can't tell where the voltage issues are, just that it is seeing them, so it is cautious. I actually appreciate that, and as a person who owns other EV's I often wonder how good they are at the same problem detection.
 
#35
That kind of makes sense. It does seem that the car is making a decision about what capacity it can charge at. I certainly adjusts the max ampage when using a 13amp socket and sometimes refuses to cjharge at all on old French wiring - I do have the correct opposite polaity chager adapter for that. Maybe we have just had more unstable volatge lately.
 
#36
Well the problem persists. And Tesla (service centre) have now admitted that there is a firmware problem. Unfortunately, it seems that sorting out firmware problems that affect 2015 MS's is a low priority. I can force it to change at 32amps but unplugging and re-plugging. That seems to work if done up to 2 hours before scheduled charge start time. It's a pita! I'm now on a 5 hour off-peak cheap rate tariff and my normal journey takes over 5 hours to charge at 16amps. Am I the only one with this problem?
 
#37
I doubt you are the only one, but most of us have invested in making sure our home wiring is in good shape. We can't control the feeds into our homes, but most utilities care enough to at least check it out if you call them.

Obviously make sure your car is on wifi so it will grab the latest updates and hope for the best!
 
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