Tesla voids warranty if you try to power your home with your car
electrek.co
electrek.co
So I misread the article at first. This is not a person trying to hook up a power source to the primary Lithium Battery, it is someone hooking up an inverter to a 12v lead acid battery that their Tesla also has.
While I would agree that hooking up an inverter to the primary battery is one thing, voiding the warrenty for hooking up an inverter to the lead acid battery is entirely different, and I would be furious if a dealer tried to void a warrenty on my car based on a $100 car battery. I actually wonder if what they are doing is illegal under the Magnuson–Moss Warranty Act.
What likely happened is that the inverter deeply discharged the lead acid battery, tripping the flag in the car. As an FYI, what you can do if you do this occurs is bring it to an auto parts store, they can inspect your battery to tell you if it is still good, (this is usually a free service), recharge your battery (I have often got it for free, but sometimes it's like a 5$ fee), and if the battery isn't old, that will fix it.
EDIT: if you want to read the act, it is here: https://web.archive.org/web/20130317083941/http://uscode.hou...
But in reading here: https://apb-law.com/understanding-magnuson-moss-act-relates-...
I actually think what Tesla is doing is in fact illegal.
Why do Teslas still have these wet batteries, do you know?
Also, does the Tesla not have a standard wall socket in it? Why would you need to use an inverter?
It helps conserve your actual battery and works well.
They have a separate 12v system from their 400v+ system that they use to run the motor.
I have dealt with these shenanigans with my ICE car and a dealer (they did not want to honor the warrenty for the car battery), this why I knew about bringing the battery to an Auto Parts store.
If you are curious about my situation, essentially my fiancee went and got the battery replaced at the dealer (we brought in the car for a different issue, and the dealer wanted to replace the battery).
About 6 months later, the new battery failed, and this battery also had a very clear sticker saying "3 year warrenty" right on the battery (it was certainly not an OEM part).
An auto parts store which helped me confirm that the battery was dead (they were actually very helpful, they offered to charge the battery and diagnosed the issue free of charge).
After working with the auto parts store, I called the dealer asking about this. They wanted us to bring the car to them, charge us a $100 diagnostic fee (essentially, doing the same thing the auto parts store did for free), then they would decide if it needed replacing, and not commenting on whether they would honor a free replacement. The battery at the auto parts store was $100! I just decided to buy the battery and install it myself. That battery does have a five year warrenty.
I strongly suspect that the original battery was never replaced, based on how they treated my fiancee in both interactions.
the batteries wouldn't like it. where-as alkaline & lead acid batteries are efficient at low-discharge, lithium ion batteries generally don't enjoy low-discharge . buck converters are also probably going to be more efficient when they have some modest load to deliver- otherwise the drive circuitry & mosfets are consuming some (little) juice, just to produce a trickle of power.
in general this is an automotive vehicle using automotive rated electronic parts. having a conventional 12v battery-powered architecture for most systems makes loads of sense, is is hella convenient, and based off my above reasoning i'd guess more efficient. yes with that low-drain the inefficiency feels like it probably won't matter but I rest easier thinking that the li-ions can truly rest when the car is off. it's better for them.
Tesla has decided to not provide a 120v inverter from the factory. It's not the underlying tech, because other manufacturers do ship inverters and they're a straightforward thing to integrate (as the manufacturer) with the HV battery pack.
This is probably about (besides the normal Tesla-being-the-Apple-of-car-companies) battery pack degradation. Tesla currently warranties their battery packs based on mileage, and frequent use as a stationary power bank will put more cycles on the batteries.
There is precedent for this - ICE vehicle warranties can be voided for excessive stationary operation. Generally they don't bother for light duty, but medium and heavy duty trucks with PTO have maintenance requirements and warranty terms based on engine running hours as well as mileage.
From linked article:
> Through the low voltage architecture, you can get the power from the main battery pack and power several devices on the inverter.
I don't know how Tesla is wired but this article suggests that 12V lead acid battery is constantly charged from primary lithium battery. It sounds like hooking up electrical load to main battery but with extra steps.
My 17 Volt has a 175 amp DC-DC converter that charges the 12v battery from the traction battery. It's interesting that this converter is cooled via the same liquid cooling loop that cools the traction battery.
I have a 4kw inverter connected to it and have used it several times to power large loads for several days in my home during power outages, including refrigerators, lights, TV/Computers, vacuum cleaners, and also the furnace(as the guy in the article has).
I have been doing this since I bought the car in 2018 and the only ill effects are when I forget to turn it off(when the vehicle is off) and it drains the 12v battery. I've done this (drained the 12v battery accidentally) about 20 times so far and it has not noticeably impacted the 12v battery.
I also would not expect any warranty support for this charging system and battery as I am clearly using it outside its intended purpose.
Warranties are for intended use. If I drop a boat out of a helicopter on onto concrete from 1,000 feet and it breaks, I can't make a warranty claim. This is SPECIFICALLY covered in the warrenty for TESLA's as well.
Now we are getting legal advice on HN that this violates the magnuson act! This is an only on HN comment.
This is not how these batteries are intended to be used.
Lawsuits like this are why we have crazy warning labels in Americas on things.
The standard approach here is warranty doesn't cover the part you damaged through misuse. So if you stab the car seats with a big knife, they won't give you new seats, but that doesn't void whole warranty.
Some things do void entire car warranty, those are pretty standard as well. Things like salvage title, submerged in a flood etc.
Others void out powertrain warranty or larger areas, usually pretty logical (flash cars computer with a tune, race car and destroy engine probably one of the more common ones?) Even though just engine may be obviously destroyed, you might lose warranty for entire powertrain (clutch / transmission etc).
I didn't offer legal advice? I said based on my reading, it violates this act. Feel free to show where I am incorrect?
If you want to argue based on the merits of my argument vs saying "This is an only on HN comment", what would your thoughts be if Ford/Dodge/etc. void my warrenty because I idled my car and hooked up an inverter to my lead acid battery?
Let me 100% clear. If you kill your battery because you idled a car and hooked up an inverter then Ford will not cover this claim. That is misuse.
https://www.ford.com/cmslibs/content/dam/brand_ford/en_us/br...
"misuse of the vehicle, such a driving over curbs, overloading, racing or using the vehicle as a stationary power source".
Yes - you can do it. No, they do not have to pay for the damage you cause doing this. I've always known this.
This idea that you can do something that clearly caused damage in the linked article and then TESLA, not the owner of vehicle owes money is backwards.
A warranty covers use of the vehicle for intended purposes, not misuse. The user caused damage by misusing the vehicle, in fact, the very damage one would expect.
It's a totally reasonable use-case and is done all the time for a variety of reasons. It works just fine using an inverter like this one:
https://gpelectric.com/products/3000-watt-industrial-pure-si...
... and although we use a different emergency power solution now[1], we used an inverter like this with the plain old car battery in my Chevy Silverado for 5-6 years.
The issue is not that a 12v lead-acid battery can't be used for this - it's a common use-case, actually - it's that the backing store for that 12v battery is usually an ICE with a full gas tank and not a big bank of lithium batteries.
But I don't see why it wouldn't work just fine ...
[1] The excellent DEWALT FLEXVOLT Power Station which is a charging station for four 9AH tool batteries but you can also plug into it and get power out. So you use the batteries you already have for tools, you get a nice quad charger, and you have hours of 15A power out.
9 Amp-hours at 20 volts is .18kWH x 4 batteries is .72 kwh. Not bad (though far below Tesla's battery which may be 100x that).
A good car battery might be 40AH at 12 volts or .5kWH? But if discharge rate is high you get less capacity.
Someone running a 2kW inverter, is going to discharge the battery in 15 minutes. Then you add Peukert constant [1] of 1.2 or so? Maybe half that? Then you realize you need to stay above 80% DoD? Even worse? So a 2kW continuous load is CRUSHING this battery. A light bulb is 100 watts. any type of motor / blower etc is going to be what would be considered a high draw.
When a refrigerator starts you may also be load spiking.
All this could damage the charging circuit to the battery which was almost certainly not designed for this load story (hopefully not)
You may be discharging at a higher rate then the desired charge rate, so just keeping an AGM charged at high draws may wreck it.
Plug in a 20W charger? No problem, the math says that should be pretty easy to handle. A 2,000 watt inverter? Short burst? No problem probably. Continuous - probably going to be a problem as the user found out.
There's a reason everyone refuses to replace these batteries used this way.
[1] https://en.wikipedia.org/w/index.php?title=Peukert%27s_law
Note - I absolutely think Tesla should support this use case, a 100kwh battery pack in your house for when the power goes out would be amazing. The the HV pack could absolutely support house loads for most everyone. You've paid 60K for the battery and vehicle, what a use case that would be! But they'd need to a different path probably through charging cable and the regulatory hassle could be annoying - pushing a lot of power back into household circuits - the liability etc risks go up (but could probably wire as if it were a generator with a transfer switch and islanding etc)
It's hard to tell because this article is pretty terrible. It depends on what they mean by "voids warranty". If Tesla just won't replace the 12v battery for free because he deep-cycled it out side of the intended use, that seems pretty reasonable to me. If Tesla tries to use this as an argument against replacing any other part of the car (including the main battery), I think that's pretty clearly a violation of the Magnusson-Moss Warranty act. IANAL.
He was pulling 12v from the 12v battery, but the car was topping up that battery from the main power pack. So he was effectively drawing power from the main pack. This would impact more than the 12v battery. I doubt tesla ever anticipated the 12v battery being discharged so quickly/continuously. They probably just don't know how this might impact any number of systems. An overheating 12v charging/rectifier system could fry something totally unrelated. This is exactly the sort of situation where a warranty for the entire car could/should be voided.
Obviously there are things that should still be covered, but there is more potential for harm here than just to the 12V battery itself.
Anyway the Tesla doesn't generate power during driving like a regular car does, so the 12V power is always topped up from the main Lithium battery and the DC-DC converter needs to be reasonably sized to accommodate eg. 600W supply. If power was taken from the regular port than i would count it as regular use (eg. when camping i would count on my car to charge things, even if it uses fuel and generates 0 km/miles.)
What if you keep jump starting another car with leads directly attached until the LA battery is depleted? That is a very common scenario and Tesla should size the electronics correctly or make it resilient for that use.
It’s also clearly stated on the owner manuals.
That LA battery is there for a reason. I don’t work with Tesla, but I would assume it is there as a backup for the monitoring and safety systems. There is a reason they are using an LA battery in a lithium powered car.
https://pbs.twimg.com/media/EuodaE6WQAA3tKN?format=jpg
It looks like they just didn't honor replacing the 12v battery under warrenty, which makes this article pretty much a nonstarter.
> The Tesla service center said that the battery needed replacing, but they actually found this post on the Facebook group and said that his setup voided the warranty.
So they refused to replace the battery
> The New Vehicle Limited Warranty does not cover any vehicle damage or malfunction directly or indirectly caused by, due to or resulting from [...] Using the vehicle as a stationary power source
Per a plain reading of the warranty, it still applies to unrelated damages. That doesn't contradict the service center declining to replace the battery under warranty.
Read through the warranty t&cs on pretty much any device. There is verbiage stating that if you arent using it for the intended purpose then the warranty is null and void. This is standard practice and generally a reasonable thing to have in a warranty. If a device/car/whatever is built for one thing and you decide to use it for not that thing then why should the company have to do additional leg work to decide if it is harmful or could damage the <thing>.
Sidebar- Maybe its a good idea to not post your entire life on facebook, twitter, insta, whatever. Alternatively the expectation should be that there could be unintended consequences.
Lexus/Toyota won't even let you jump start another vehicle if you have a Hybrid. Not only will they not warranty the 12v battery, but also other electronics that you end up damaging.
"Exclusive jump starting terminal precaution The exclusive jump starting terminal is to be used when charging the 12-volt battery from another vehicle in an emergency. It cannot be used to jump start another vehicle."
https://www.rav4world.com/threads/12v-battery-dead-on-2017-x...
https://priuschat.com/threads/jump-starting-the-prius-c.1207...
How is that clear? I am curious where in the article that was made clear to you.
The Headline is "Tesla voids your warranty if you try to power your home with your electric car battery pack", and another section "The Tesla service center said that the battery needed replacing, but they actually found this post on the Facebook group and said that his setup voided the warranty."
Click the Twitter link from the article. There is a picture of the owner where he said on he FB post: "So I bring it to Tesla and they are replacing the 12v not under warranty" Source: https://pbs.twimg.com/media/EuodaE6WQAA3tKN?format=jpg
I think we can all agree that the article headline is clickbaity.
It should've been "Tesla voids your 12V battery warranty if you try to power your home with your electric car battery pack"
It was also crafted to never mention that it was 12V battery that was voided. They just vaguely say "voided the warranty" but never cared to mention what part of the vehicle.
If you had provided that source in the first place, I would have agreed with you.
It’s also worth mentioning that the original story was actually posted on the /r/teslamotors subreddit.
The author has a bad reputation there of lurking and making zero effort articles like this one with a catchy headline. Leading to him being booted as a mod.
He also never credits Reddit users.
This is, from the warranty's point of view, the same as manipulating the odometer on an ICE car to make it appear to have driven fewer miles than it actually has.
Your first paragraph is spot-on, but your second claim couldn’t be more wrong. It’s akin to powering your home off your ICE car’s alternator and an inverter which wouldn’t register as miles driven on the odometer.
Well, no, this is the same as running your ICE car a lot without driving it. (Which is actually common for some ways people use cars.)
Some cars and all-ish heavy machinery count the amount of time the engine is running. (It's not common for cars to base their warranties on this, but only calendar time and miles, as far as I know.)
No miles would register but you'd still be putting a lot of wear on the engine. I doubt the warranty for the ICE vehicle would cover this.
In all these cases that would be intended use, so.
The odometer is generally computed/measured at the output shaft of the transmission. The differential+tire size is then used to compute a mileage in the ECU (or old school via actual odometer gears feeding the odometer).
Its also why the discussion about adjusting ones odometer comes up frequently in offload communities where oversized tires, or differing gear ratios are run. Even outside of that, people (like myself) who run slightly oversized AT tires, even on the street have our odometers thrown off by a couple percent because the manufactures frequently don't provide a real number input to the ECU rather a selection of a few tire sizes. In my case, my truck has metric sized tires, which don't align perfectly with the preprogrammed LT sizes.
That is why there are various inline devices which can be plugged in to correct for nonstandard modifications (I believe this to be one of them http://hypertech-inc.com/SpeedometerCalibrator.aspx, from a random google search)
Not impossible, but probably not practical and certainly likely to void various parts of the warranty.
If they are going to void the warranty anyways, they can simply calculate the equivalent miles driven with the amount of Ah used and use that as a basis for voiding or not.
Assuming the load characteristics of a house are the same as a car is a pessimistic assumption.
No, one implies active deception. The other is "unaccounted for use case".
This is (another) example of Tesla expecting customers to not just collect data for them, but pay for the privilege - witness the replacement of the eMMC which Tesla considers a consumable despite its inaccessible location and despite the fact it is not the owner "consuming" it, but Tesla, capturing telemetry data to send to Tesla for Tesla's benefit.
I rather doubt there's anything in the Tesla Bill of Sale that obligates me to provide battery health telemetry data to Tesla for their monitoring.
In the end it will need to be competition and regulation that prevents all EVs, the industrial complex, from taking advantage and extracting more than is reasonable based on costs.
I don't think any other car maker will warranty an abused 12v battery.
Car Maker's typically don't make the 12v battery, some third party does, and the warrenty is typically through the third party. A typical 12v car battery is also lead acid, and a lead acid battery behaves radically different as comapred to the lithum batteries with charging and discharging, and lead acid batteries age differently too.
I would have no problem "abusing" a 12v lead acid battery (and there are plenty of sites out there to show how to store energy for your home using them), but I would not want to attempt that with a lithium battery. Why? Without the proper charging/discharging circuitry, those things can catch fire (thermal runaway), and that can't happen on a lead acid battery.
However, I would argue that due to the aging of the battery combined with the danger of adding third party discharging circuitry, I would agree that this would void the warrenty, as I would imagine the car cannot now monitor the aging of the battery now. I would not be happy to get a used tesle to know that the battery is significantly more aged than what is reported.
EDIT: I apperently misread the article, and assumed the inverter was being hooked up into the Tesla battery, but Tesla has a 12v lead acid battery.
Re-reading the article, I am actually surprised about this now. Tesla is voiding the warrenty from using the 12v lead acid battery, NOT the primary lithium battery. This may actually be illegal under the Magnuson–Moss Warranty Act.
I do recall that the battery was split open and its guts had hit the ceiling.
Vehicle alternators(the device that charges the battery while the engine is running) are not designed to continuously output that kind of load and would likely be damaged if it were used for any significant duration at that load.
I have done this myself with a non-electrically propelled vehicle and have damaged(due to overheating) an alternator in the process.
It's the same reason fast-charge for phones only works with a specific type of cable and connector. Otherwise you could overload the battery or the burn the cable by sending too much current through the wrong cable.
The battery in the Tesla was likely sized and designed with this in mind also.
I guess ICE vehicles still have two big advantages: I can power a lot of things in emergencies and car manufactures haven't quite got in the habit of monitoring the hell out them yet.
Idling with the heater on it should get 25-30 hours on a tank. That should be long enough for either power to be restored, or for there have been enough traffic from people up my street in trucks and big SUVs to have cleared the road enough to drive out.
How well do EVs function as emergency shelter?
I have one friend with a ICE vehicle that he can plug into the house and power some essentials. He is a general contractor and has a lot of fun stuff on his truck.
How well do EVs function as emergency shelter?
I would be curious on a statement from each manufacture on how long I could run the heater in an emergency situation.
Why doesn't Tesla limit the output current of the battery and be done with it? Why this strange rule?
This reminds me of "Ferris Bueller's Day Off" and how Bueller jacked the car up to run the odometer in reverse. If we prop up the rear wheels, how fast do we have to spin the wheels to qualify as non-stationary?
is anyone else wondering how his home furnace has a regular plug? aren't these things usually hard-wired with a dedicated circuit? you usually need a transfer-panel installed to do this.
https://en.wikipedia.org/wiki/Act_of_God
"In legal usage throughout the English-speaking world, an act of God is a natural hazard outside human control, such as an earthquake or tsunami, for which no person can be held responsible. An act of God may amount to an exception to liability in contracts (as under the Hague–Visby Rules) or it may be an "insured peril" in an insurance policy.
By contrast, other extraordinary man-made or political events are deemed force majeure"
Hooking up a 2000W inverter and drawing 165 amps from a small lead acid battery is a bad idea, let alone in a vehicle.
The 12V battery wiring and/or DC/DC charger is probably also not designed to have a continuous ~165+ amp draw for a long period of time. (2000W / 12)
https://teslatap.com/articles/12-volt-battery-compendium/ The batteries mentioned here have 40 or 45 Amp-hours, which I believe would be 480 or 540 Watt-hours (amp hours * 12v), which is not enough to run a 2000W inverter for very long.
Ideally, there would be circuitry to hook up directly to the main battery safely and efficiently.
I don't know about a Tesla, but this is how regular ICE cars work. The power from the alternator varies depending on the speed of the engine, so if you are stopped at a red light with your radio, wipers and head lights on, the alternator may not provide enough power. This is why the 12v battery is still connected after the engine has started, not just to charge itself, but effectively as a big capacitor to balance the 12V power supply to the car. As long as the inverter is normally drawing less power than the high voltage to 12V system can supply, it shouldn't damage the 12V battery.
This is also why cars with start-stop usually use AGM batteries, as the battery will be run down a lot more while the car is stopped (and the engine isn't running), which would quickly damage a regular lead acid battery.
Last time our power went out I charged my 48v ebike battery off of my leaf’s 12v, then used that to power a big inverter to run the fridge.
Now I have some dedicated solar that can charge the ebike, so no need for shenanigans.
Anyone looking to do this, there are challenges, and don’t do it with a battery that isn’t built for serious discharge (mine is 1.7kwh and rated for 3k watt bursts). Most off the shelf ebike batteries will not tolerate that kind of abuse.