WARNING: Do not plug an AC inverter into your 12VDC socket!

[zack]

This caused a failure in my car's switchpack, which caused a non-start condition. It's NOT covered under warranty (so far). This repair will cost me thousands. In the Tesla "engineering blog" there is an instruction not to ever plug an AC inverter into the Tesla, but there, as far as I know, is no such warning in the user manual. I informed Tesla that I was hoping I could convince them to defeat the 5 minute limit for the DC power jack after the car's turned off, and told them that the purpose was to continue power devices inside the car such as chargers and cameras, and that that time I was not warned about using an inverter. Naturally, I'm pretty steamed about this. I've now been told that "everyday" use (whatever the &^%$* that means) of chargers and other devices will not harm the car, but sine wave inverters are not allowable.

The problem is that the inverter I used produces spikes in voltage (as much as 19V) that corrupt electronics in the car. There is apparently insufficient filtering on the DC power socket. I asked whether anything else might cause damage, since almost all power supplies these days are switchers, and was given an answer that did not sound very reassuring: "It shouldn't." What about "won't"? I'd like to get a list of approved devices from Tesla. I just called them and told them so. This is infuriating. Basically, they're so much as telling me "Don't use the 12VDC socket. It's not for customer use."

 

[cinergi]

That almost sounds illegal to me (IANAL)...

 

[doug]

Umm... yeah... that sounds like a design oversight. Where is this engineering blog? If this is a known issue it should be in the manual or on your warranty agreement.

 

[Doug_G]

They can't argue that it is an inappropriate use for the connector if there is no warning in the manual. Everyone uses inverters in their cars. It's a normal and expected use for the connector. Why else would it be there?

So tell them without a clear warning in the user manual they can't retroactively tell you that you can't use an inverter. It is therefore their fault.

If they still refuse, tell them your lawyer will be in touch.

If that doesn't do it, then go to your lawyer and have him/her write them a letter. It won't cost much, but that WILL get their attention. It would be incredibly stupid for them to go to court.

Last resort - hopefully in your jurisdiction it would qualify for small claims court.

 

[bonnie]

Bottom line is that unless a company supplies a list of what IS allowed (and says nothing else without their okay in writing), or is clear about what is not allowed, then they can't disclaim the expected.

This is why even sunshades say 'remove before driving', steam irons are labeled 'do not wear clothes while steaming', and hair dryers advise 'do not use while bathing'. Risk management. If you can't design out the problem, then (assuming not a safety issue) you at least need to tell the user about it. And there should be a label on the plug telling you NOT to plug in any unapproved device. The manual isn't enough. And an engineering blog is definitely not enough.

 

[TEG]

How big an inverter was plugged in? The 2010 Owner's manual seems to say

"Note: The power socket is suitable for accessories requiring up to 10A or a maximum of 125 watts."

 

[strider]

Hmm. Poking through my 2.5 manuals.... There's nothing in the Owner's manual about inverters in the section on the Accessory socket. It simply lists max power draw. However, in the Warranty Guide, in the section "What is not covered" it states, "Misuse of the vehicle, such as driving over curbs, overloading, or using the vehicle as a stationary power source". I wonder if they'll claim that the use of an inverter is using the vehicle as a power source? But what if you're using the inverter while driving?

So yeah, I don't see any prohibitions listed in a location that an owner can be reasonably expected to read (ie: documents that came with the car). I don't think they have a leg to stand on. If the accessory was drawing too much power it should have popped a breaker, fuse, whatever and diagnosing/fixing THAT I could understand being charged for. But if they allowed an accessory to wreck whole systems in the car that sounds like a clear design flaw to me.

 

[efxjim]

If you have an item that needs the accessory socket to be left on (IE. phone charger). After you turn off the car, turn on the parking lights. It keeps the main 12v power on continuously. The lights do not draw a lot of power. The down side is your parking lights are left on. There is also a small amount of 12v power that is always on available on the OBD port. I'm not sure how much current can be pulled off this source. I am running a charger for my in car tablet and power for a mobile hot spot (est. <3 amps)from there. The car will charge with the parking lights on.

 

[TEG]

Related old thread with a somewhat relevant quote:

12 volt accessories?

I don't think the Roadster is designed to have a lot of extra 12V amperage capacity. Probably not a good car to plug in an inverter and try to run appliances off of the lighter socket...

 

[vfx]

I have found that my 12V accessory socket stays hot now. When the key was pulled, my Magellan GPS used to go to battery after five min and later it would die, even when plugged in. Now I leave the car all day in a parking lot 10+ hours and the GPS is still on. Maybe a firmware changed along the way this in my 1.5

 

[doug]

12 volt accessories?

I don't think the Roadster is designed to have a lot of extra 12V amperage capacity. Probably not a good car to plug in an inverter and try to run appliances off of the lighter socket...

"You just got TEGed"??

 

[TEG]

Zack, really sorry to hear that your car needs repair...
Also unfortunate that it appears to be touchy as to what you can plug into it.

 

[zack]

I haven't had anything plugged into the inverter for weeks. I used it on a recent road trip to charge some small cameras and two iPhones. It is a model that has its own battery and it charges up that battery from the car, and when the car's 12v socket turns off it kicks in kind of like a UPS (but it isn't smooth) and continues supplying 110VAC. They're going to find an inverter that works for me that doesn't cause the spikes in voltage. The tricky thing is, there aren't many inverters I've found that have their own battery back-up. Ideally it would be a true sine-wave inverter.

In my last conversation with them I explained that I did them a big favor by discovering this problem. If they released the Model S with this same issue, it would be devastating to have a bunch of cars die out there. Very bad for business, if you ask me. I was told this is the first time they've seen the problem. I manufacture electronics myself, and my US-made products carry a lifetime warranty. I'm always studying the stuff that breaks on my products and trying to improve them. I hope they come to their senses about the warranty thing.

 

[zack]

I have found that my 12V accessory socket stays hot now. When the key was pulled, my Magellan GPS used to go to battery after five min and later it would die, even when plugged in. Now I leave the car all day in a parking lot 10+ hours and the GPS is still on. Maybe a firmware changed along the way this in my 1.5

That's weird! Mine still dies and it has the latest update, but it's a 2.5. I'd report that to Tesla. Any unexpected change might be an indication of corruption.

 

[zack]

If you have an item that needs the accessory socket to be left on (IE. phone charger). After you turn off the car, turn on the parking lights. It keeps the main 12v power on continuously. The lights do not draw a lot of power. The down side is your parking lights are left on. There is also a small amount of 12v power that is always on available on the OBD port. I'm not sure how much current can be pulled off this source. I am running a charger for my in car tablet and power for a mobile hot spot (est. <3 amps)from there. The car will charge with the parking lights on.

Wow, that's interesting stuff to know. OBD port... hmm. Is this the correct pinout?

 

[zack]

Just a little warning to anyone who is using tricks to get the DC power jack (or the OBD port) to supply power when the car is turned off, if you drain down the backup power source you can cause a lot of damage to the car and it won't be covered by your warranty. They warned me about this when I asked about installing an alarm system and that's why I purchased the pseudo-UPS inverter with its own battery pack to supply power when the car is off.

 

[zack]

Umm... yeah... that sounds like a design oversight. Where is this engineering blog? If this is a known issue it should be in the manual or on your warranty agreement.

The engineering blog is apparently only accessible internally at Tesla. I agree it should be in the manual AND on the warranty agreement. It should have been emailed to all owners the moment it was discovered.

 

[scott451]

I have found that my 12V accessory socket stays hot now. When the key was pulled, my Magellan GPS used to go to battery after five min and later it would die, even when plugged in. Now I leave the car all day in a parking lot 10+ hours and the GPS is still on. Maybe a firmware changed along the way this in my 1.5

Sounds like the battery is fully charges and/or the battery is above 30C

 

[scott451]

... I hope they come to their senses about the warranty thing.

If they don't, make sure they give you the defective switchpack. You're entitled, by law, to the "defective" parts.

 

[zack]

Scott, you're brilliant.