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Last upgrade Firmware :(

Since the last upgrade Firwware, tuesday, Imposssible to charge my MS at home, Before it works very good (40km/h)

in my case, my electric power is a little bit too low and too unstable, but till last monday it was wonderful

Please, dear Tesla developers, correct the next firmware upgrade ASAP

Be sure to call them or e-mail them. They do not follow the forums closely. They may be able to research the problem while they have you on the phone.

Sometimes the car needs a reboot after an update too.

Might want to have an electrician check your wiring. Just because it was working does not mean there is not a problem.


my electrician is coming and all is OK and then Tesla ranger is coming to see the problem are the firmware upgrade

Set the amperage slightly lower on the car screen; it is now more sensitive to drops below set level, so give yourself some buffer. Shouldn't affect charge time much.

I tried but it doesn't solves the problem

Well I use a 120V outlet enough for my commute needs, It use to charge 4 miles/hour, after the update now max 3 miles per hour not enough for my commute.

Cberman, I have a HPWC but I needed to use the mobile connector last night at home on a 15 amp, 120v outlet. I got 12 amps and 4 mph charge with no problem from firmware 5.8.

If your power is unstable, as you say, your best bet would be to have an electrician install a Line Conditioner or Uninterruptable Power Supply (UPS) on that circuit. It will basically buffer the power coming in, smoothing out the surges and brown-outs allowing your car to receive clean power. Once it gets clean power, it will go back to full speed charging.

I am an electrical contractor in BC Canada. We just completed an install for a Model S HPWC in Dec. My client has the exact same issue. As soon as the new OS came out for the car it now has charging issues.

I went out to the install and checked everything. Turns out the voltage coming from the utility supplier (BC Hydro) was low. 226v rather than 240v. I contacted BC Hydro and they are sending a crew out to correct the low incoming voltage.

The new OS is picky about the incoming voltage. After BC Hydro finishes their repair I will check out the option for a surge protector if required (probably not).

If anyone has questions regarding this you may email me directly.

Brian Wuttke
BW Electric

I charge at my work with a Clipper Creek J1772 charger. Voltage is only 197, 30 amps. The latest firmware does not cut the charge rate on the car. Maybe it is a stable 197 volts?

There are two voltage standards in North America - residential split phase at 240V and commercial 3 phase which gives a nominal 208 volts, no load. So 197 volts from commercial power is fine.

It is entirely possible that Tesla is not only protecting against faulty house wiring, but also from an overloaded local grid/utility transformer. Which would make it sensitive to voltage that is too low.

This is the intended functionality of the latest 5.8 release. If the voltages fluctuate the car puts safety first and disallows charging.

This is in response to an electrical fire in the US involving a Model S and a poorly installed outlet.

Sorry to hear about your charging woes nonetheless. Perhaps the previous poster in BC can assist you in rectifying the problem. :-)

This new software upgrade, while having good intentions, has made my nightly charging very frustrating. While I had no problems in the past charging at 40 Amps, now I frequently get downgraded to 30 A despite stable current at my outlet. This is a particular problem because my utility has lower rates (5c/KW) from 1AM to 5AM. I could get the majority of my battery charged in that timeframe. Now it takes longer & costs more. Hope to see the sensitivity dialed down in the next update.

Since the last upgrade impossible to charge at home with 3-Phase 400V in Belgium and nor in Shoko 220V at Work (before it was OK) Only Mennekes T2 works on public charge, who cost me more than in house and i don't speak about confort…

Regards the quality of this brand, i expect a quick respons

For those having regular issues, the solution is not for Tesla to relax their restrictions, at least not just yet. The first course of action is to have your power looked at, just as Brian4591, comments. You are paying for a certain level of service from the utility and they should deliver within the standards. There are other issues you could be having or could have in the future from substandard power. If utility power issues are suspected, your circuit should be tested over time with an attached meter, not just spot tested.

@ Koz:

ok but never Tesla did not provide the minimum quality of my electrical connection at home and as soon as I got my car I did not know the charge, I already invested in a transformer and everything worked and now Tesla modifies Firmware and nothing works.

do not say that is not the fault of Tesla

@CallVince - @Koz is correct in pointing out that the electrical lines should be checked by the your local utility to verify uniform voltage. What if there really were issues with your charging setup which may overload the circuits?

The latest firmware release detects charging fluctuating and adjust accordingly. You should also contact TM service center to verify there aren't any issues with your car or the on board charger.

I made 2, but my electric supplier will not change anything unless I put a new cable 1 km at my expense ... and the TM service center has checked my car, it is only Sofware not Hardware

We are located about 15 miles south of Carmel, Ca in a rural area where PG&E service is known to be sub standard. PG&E has no intention of improving the local infrastructure. In addition we are about 500 feet from the street. 228-230 Volts with some fluctuation is what we receive.
We have #4 Aluminum to the house and #6 copper to the garage, all installed up to code by an electrician. Prior to the update charging was 40 amps providing about 30 miles per hour, since February. Now 30 amps providing 21 miles per hour.
Tesla wants us to have my charging cord checked. Will do, but the firmware update is clearly sensitive to the lower voltage.
Tesla needs to modify the firmware update to allow for slightly lower voltage with minor variation, which appears to be quite common.

I recently noticed that our MS was charging at 30 amps and I could not raise the setting back up to 40. I called service for advice and they checked the record and said, the car detected a voltage fluctuation on 12/31 and set amps down to 30 accordingly. I mentioned that all the wiring was new, that there was actually a fairly minimal voltage drop at charging 40 amps, but if our geothermal heat pump turns on, which is does several times a day, that could cause a very short term voltage drop. Same for starting up the amp in our home theater. They then had me unplug and reboot the UMC, reboot the car, then plug back in and sure enough I was up to 40 amps again and still is a few days later. So it seem like a short term fluctuation during charging can lower your charge rate and it will stay lower indefinitely. This can be reset, but obviously should only be done if you are sure all the wiring is good with no poor connections.

How to downgrade? it's possible?

You can select your desired amperage on the charge screen, which will be remembered by GPS coordinates.

@kickgas - Or maybe you could accept the fact that there's a potential problem with your wiring and get it checked...


Exactly. As per usual some people can't be helped though.

Word to the wise; security mechanisms are in place for a reason.

You can follow Tesla's reasoning in the press release:


Thanks. That is very helpful info and Tesla should have conveyed this in the upgrade details. Almost everyone will see some power fluctuations, probably a lot of people on a pretty regular basis. This means resetting pretty often for a lot of folks. Not sure if Tesla should change the reset to automatic each time the car is plugged in but they should consider it for a future upgrade if it is possible.

For those that have significant power issues, I think you should consider installing power conditioning equipment as previous posters have mentioned. That is a better solution than Tesla disabling the protections that are meant to protect your interests (and theirs through you) IMO.

So what is the solution for me

I have already invested more than € 2,000 to suit my network and I must still buy a 400V UPS? Price?


sell my Tesla and say over the press that Tesla does not meet its commitments


Tesla provides a good firmware who works at home

That realy sucks. My in house wiring is not a problem. All my fluctuations are from the local utility and now I can't charge over 30A. It's my voltage that's fluctuating and pulling 40A at 238V represents no risk in my home. My stove will now draw more than my car. Rediculus!

I 've tried with 6A but the same problem (problem of cable) or i've tested with an other cable from Tesla Rangers and it's the same error, my cable is good

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