Last upgrade Firmware :(

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

Captain_Zap | January 9, 2014

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. | January 9, 2014

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


CallVince | January 9, 2014

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

Brian H | January 9, 2014

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.

CallVince | January 9, 2014

I tried but it doesn't solves the problem

carolinagobo | January 9, 2014

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.

Big T | January 9, 2014

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.

Haeze | January 9, 2014

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.

brian4591 | January 9, 2014

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

jcaspar1 | January 9, 2014

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?

shop | January 9, 2014

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.

shop | January 9, 2014

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.

Jewsh | January 9, 2014

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. :-)

kickgas | January 9, 2014

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.

CallVince | January 10, 2014

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

Koz | January 10, 2014

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.

CallVince | January 10, 2014

@ 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

Mathew98 | January 10, 2014

@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.

CallVince | January 10, 2014

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

mcptwo | January 10, 2014

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.

shs | January 10, 2014

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.

CallVince | January 10, 2014

How to downgrade? it's possible?

Bighorn | January 10, 2014

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

GeekEV | January 10, 2014

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

Jewsh | January 10, 2014


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

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

wcalvin | January 10, 2014

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

Koz | January 10, 2014


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.

CallVince | January 11, 2014

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

Tanchico | January 11, 2014

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!

CallVince | January 12, 2014

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

kenj | January 12, 2014

When my electrician installed the 14-50 outlet, they noted a high voltage situation and said I needed to call the utility company.

Called the utility company, noted a problem at my meter caused by a bad "neutral", the utility company asked had I experienced any issues -- bulbs blowing out etc. Said I did not. I would not have know without the install.

The software update does the same thing to protect you and the charging cable from overheating and fires.

You might want to have your utility check -- in New York, the utility company is required to provide a steady level and provide whatever protections needed to ensure that. I understand this is not the case everywhere -- but you may want to check with the utility provider before investing in additional electrical solutions.

Doesn't the HPWC include the UPS and other protections? (even if you do not install for the higher charge rates.

Jewsh | January 12, 2014


"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"

So in your mind Tesla should risk a fire or damage to your Model S for your convenience? When the fire starts, the press won't blame you - they'll blame Tesla. (Like usual.) Good luck with that.

FYI I read that running equipment below the intended voltage generally causes their VRMs to get quite hot. Just because you haven't had any equipment fail yet doesn't mean you won't. Low voltage is a problem and you should concentrate your efforts on pressuring the power company to fix the issue. Right now they're not delivering you power at spec. This issue affects all of your home's equipment, not just the Tesla.

Haeze | January 12, 2014

I am still curious why this is an issue causing enough concern to sell the car.

Stepping down to 30A still means you are charging at 20miles per hour which means a nearly full charge in 10 hours.

As an owner who is just fine charging at 5mph, I find it odd for anyone but a doctor or real estate agent to be concerned about charging at 20mph vs 28mph.

CallVince | January 13, 2014

But why it works before, without any risk?

Before the last update, i was the happiest man of the world!!!

Chuck Lusin | January 13, 2014

#4 Aluminum can handle the same current as #6 copper. Sound real small for a service.

dpawson | January 13, 2014

"But why it works before, without any risk?"

That doesn't sound like the correct usage of the word "risk". If you decide to go rollerblading in the middle of a highway, you undertook a lot of risk, even if you manage to escape without getting hit. If you do it again tomorrow, you might not be so lucky. Just because you didn't have a fire or other electrical calamity doesn't mean something wasn't wrong. Electricity in particular is a very fussy thing.

theapple | January 13, 2014

@CallVince downgrading should be possible. Last time I had my car in for service, they "upgraded" my firmware to 1.49.24. Except I was already on 1.49.30, and I got the "upgrade is available" message as soon as I left which brought me back to .30.

I'm glad to see this topic getting some sunlight. As an electrical engineer, the latest firmware updated seemed like a hasty band-aid for a hardware problem (saves them having to recall hardware), and I have been refusing the update every time I start my car, precisely because I feared this issue. Many things can cause voltage fluctuation besides a melting connector or other unsafe condition, and I need my car to charge reliably/predictably. I also have significant doubt that voltage fluctuation and 25% current reduction will significantly detect and stop thermal runaway in the connector in the first place.

Hopefully Tesla will roll out the thermal fuse hardware fix to everyone and revert the firmware to the way it should be. Until then, feeling vindicated, I will continue refusing the update. Thank you for sharing your experiences.

mark.dershwitz | January 13, 2014

I am frustrated that there is no manual override to the charging limit (as there was with the early HPWC's that had the smaller fuses).

With no current flowing, NStar supplies my house with 242 volts. I can no longer charge at 80 amps through the HPWC because the voltage drops to 227 volts at 60 amps and the new software won't let the current be adjusted higher.

NStar says that the voltage drop, that takes place outside of my house, is within their spec and completely safe. I informed Tesla by phone of this today and asked for a manual override option in which the customer takes responsibility for using the HPWC at its highest current.

There are times in my life that a 60-amp charge is just not fast enough and that's why I invested in the HPWC.

tghoxie | January 13, 2014

This is clearly a problem. The new software is simply too restrictive. Many of us have fluctuating voltage.

shs | January 13, 2014

When it comes to detecting fire danger, a thermal sensor/fuse is the ideal as it will not be influenced by upstream losses. I agree with earlier comments that once the thermal solution is in place - l.e. we all have are new 14-50 adaptors, Tesla will likely relax the voltage fluctuation sensitivity of the current software release.

brian4591 | January 14, 2014


A whole home surge protector will help with the voltage fluctuations and is not an expensive device. I might install one at the installation I was mentioning above in a previous post. I am waiting to see what our local utility (BC Hydro) changes will help with the situation. I am expecting the utility change to fix everything. They will be adding a new transformer on the pole right outside the home as the voltage from them was not to "their" standards.

I'll update if I have any more info.

PS. This is NOT the fault of Tesla's update. It is a preventative measure for personal and property safety. It is something that owners should be happy about. You would be a LOT more upset if the fluctuating voltage caused damage to your car or home.


jhelberg | January 15, 2014

I almost rejected the new 22kW installation at my office, due to the fact that my Tesla charged at 12A. Luckily the service provider knew about the Tesla issue and told me to wait for two minutes and then put the Amps up fro the display. To 26A he said. `Surely you mean 32?' No, he meant 26A. He told me Tesla will come up with a fix for this in January 2014.

It would be nice if the mobile phone app could adjust the charging Amps, I have to go outside now after 2 minutes.

Theresa | January 15, 2014

I am wondering if Tesla has not allowed a long enough period of time to adjust the current rate. In the aerospace industry we do things like a three strike counter to prevent inadvertent failures. I think that if Tesla made the algorithm such that it would take a longer period of time before lowering the charge rate (which would allow for normal fluctuation of voltage). Also it could check to see how often it happens so if it is happening frequently then it lowers the rate as well.

Currently it appears any lowering of voltage or current causes the setting to be changed.

CallVince | January 26, 2014

Finally it work's

1. my electrician is coming to improve my neutral, from 39 ohms to 11 ohms
2 in my Tesla, First select 6A, an wait 30 seconds that the electrical current is stable
3 increase up to 12A (37 km/h)

Whereas before i could load carefree 16A … (40 km/h)

brian4591 | January 28, 2014


What?!?! Really confused as to what is going on...

brian4591 | January 30, 2014

**Update** As per my conversation above.

BC Hydro has fix the poor power issue and now the car is charging perfectly!

Brian Wuttke
BW Electric