Using MYLR wheels as an electric generator during an emergency

[e645824]

I've created this thread because I'm frustrated on a path forward during a real electric blackout caused by some event or a California "scheduled" blackout. The Tesla warranty only allows things plugged into the wimpy 12V cigarette lighter port. Using an inverter to clip-on to the 12V battery is the preferred method in an ICE car, but we know that this is driven by the Tesla 12V charging circuit and it might complain. And the 12V route is too wimpy anyway for my needs. Ideally, we would just use the 400V main battery and an inverter, but that involves disconnecting the 400V cable and the Tesla computer might trigger the safety disconnect. Tee'ing off the 400V line seems like it should work, but the computer might see this as a phantom-drain and trip something.

So at this point, the best concept that I can think of is to:

1. jack the car up,
2. remove the wheels,
3. attach generators to each of the 4 (so that the load is balanced),
4. attach a big pure-sine inverter to those,
5. set cruise control to a constant speed,
6. plug my 240V AC loads into the inverter (240V well pump and two 240V window A/C units)

A dyno + generator would logistically be easier but the risk of the car zipping off is a concern.

In googling around, I'm not able to find the right combination of search words for this setup. Power goes out a couple times a year, and California seems to be trying really hard to make it worse. I have a farm in the country, so the utility repair crews takes longer for me than for folks in the city.

If the 400V battery gets low, I'd put the tires back on, run down to the nearest SuperCharger that has power, charge-up, then come back home.

Keep in mind this is only in case of an emergency (just like my two 240V whole-house window A/C units are there in case of an emergency). But when it is 110 degrees outside, doing without A/C is not an option. Before the Tesla, I'd pile the family into a car and we'd just go to a movie theater for many hours or a hotel is the outage is for days. But with 80kWh sitting in the driveway, I'd like to use it.

Any recommendations on a viable path forward?

Thanks,

Scott

PS yes, yes, I'm the perfect candidate for a PowerWall and solar. Can't afford it right now and would wait for an LFP PowerWall anyway. Looked at EnPhase but they quoted $60k. Nope, I'll buy 4 generators instead to mount on my MYLR. I won't do gas-generator backup; lots of neighbors had them at one point and discarded them for all of the usual reasons.

--

MYLR | Red ext | White int | 19" | 5 seats | tow | no FSD | made/delivered Oct 2021

 

[e645824]

For example, here is a tractor PTO generator producing 10kW:

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https://www.electricgeneratorsdirect.com/IMD-PTO-10-2S-AVR-PTO-Generator/p5887.html​

Tractor PTO's run at 540 rpm, which on my MYLR with OEM tires is 45 mph (Continental ProContact RX 255/45-19 104W have a tire diameter of 28 inches). So having an adapter from the wheel bolt pattern to a PTO should allow easy connection.

To only use 1 of these, it seems that I'd need to lock the differential and attach on the back. But I've seen mixed reports if my MYLR has an open differential or a limited slip.

Or this smaller 7 kW unit:

https://www.northerntool.com/shop/tools/product_200308467_200308467​

Scott

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MYLR | Red ext | White int | 19" | 5 seats | tow | no FSD | made/delivered Oct 2021

 

[jcanoe]

Assuming this could work it would void the Tesla new vehicle warranty for the rear drive unit, rear axle, etc.

Why not just get a standby generator that runs on diesel fuel or propane if natural gas is not an option.

 

[Big Earl]

A few potential issues:

1. Each axle/motor has an open differential that drives the wheels. How do you intend to sync all four generators? Ideally, you'd do this on a rear wheel drive car, keep one wheel on the ground and mount a generator to one wheel.
2. There is no basic cruise control function - only traffic aware cruise control, which won't work with the car parked in a driveway or a garage.
3. The car will need to by in dyno mode so stability control doesn't try to fight you - even then, you might run into problems with the car freaking out.

 

[Sophias_dad]

Ya, this is totally nuts I mean this in a kind way.

Aside from other problems mentioned, the diffs will cause horrendous problems. There's nothing to synchronize the generators from one side to the other, nor between axles. The between-axle problem is probably worse, since one axle will always be getting more torque. The way I understand it, for cruising the rear wheel motor is used almost exclusively.

That smaller PTO generator is $1279. Four would therefore be $5000, and then you'd need another $3000 in metalwork before there would be any chance whatsoever that it would work. Even ignoring the extra work, $5000 will buy you a really nice propane or natural gas based generator and tank that would do exactly what you want and would even be designed just for your application.

 

[ucmndd]

People have proposed a whole bunch of crazy stuff on this forum, but this one might take the cake.

 

[Unclepaul]

Tesla and other EV manufactureres are hard at work, trying to develop a way to tap into EVs batteries to power homes during short losses of electricity. Would wait until they get this all figured our before you go Rube Goldberg. Perhaps better to simply get a generator sized to your need for those potential outages.

 

[Empiro]

We already know that the Lightning can be used as a battery backup. If it's a popular feature, I can see other manufacturers following suit, including Tesla.

 

[e645824]

Ya, this is totally nuts I mean this in a kind way.

Aside from other problems mentioned, the diffs will cause horrendous problems. There's nothing to synchronize the generators from one side to the other, nor between axles. The between-axle problem is probably worse, since one axle will always be getting more torque. The way I understand it, for cruising the rear wheel motor is used almost exclusively.

That smaller PTO generator is $1279. Four would therefore be $5000, and then you'd need another $3000 in metalwork before there would be any chance whatsoever that it would work. Even ignoring the extra work, $5000 will buy you a really nice propane or natural gas based generator and tank that would do exactly what you want and would even be designed just for your application.

Thanks. I don't have natural gas or propane. And California limits the kinds of gasoline generators that we can purchase. Plus, for a unit that sits idle most of the time there are maintenance issues. That's why I'm avoiding gasoline generators. I had several neighbors with portables, Generac, etc. and when it was time to crank them up, they didn't work for some reason (I'm guessing lack of fuel stabilizer, or oil issues, or the 110 degree heat, or ...). For two of them, their solutions were large ground-mount solar racks (but no batteries). The rest do what I do -- off to the movie theater the next town over; or to a hotel when more than 1-day outage.

Based on the comments (above), using 4 units is too problematic. And doing just 1 unit is bad for the diff/axle.


Thanks to all for the advice. Looks like the thing to do is to wait for a simple 400V solution. That big orange connector is awfully tempting

Thanks,

Scott

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MYLR | Red ext | White int | 19" | 5 seats | tow | no FSD | made/delivered Oct 2021

 

[Sophias_dad]

Thanks. I don't have natural gas or propane.

There are plenty of folks around here that don't have NG available at their home. They instead stick a 100-200, maybe even a 500 gallon propane tank in their yard. There's no reason you'd need more than 100. Propane also doesn't go bad like gas, and some generators will have a mode that runs the generator for N minutes per week/month to keep it exercised.

Here's a link I found elsewhere on TMC about getting more power from the 12V.. Marc's Blog: electronics - Using a Tesla Model 3 as Emergency Power Source In Case of Grid Failure

Side note: If you happen to have another ICE car available, you should be able to use it as a 12V supply, although different cars will have different at-idle and max alternator output. 130A is a 'typical' max(leading to perhaps 1400W available output), but I assume you'd have to hold the engine at somewhat above idle speeds to get that. You might be able to install a different pulley/alternator to get considerably more idle output, with a larger max as well. Please also note that idling a car for extended periods is verboten in many states.

 

[Unclepaul]

Your friendly local propane supplier will rent you a tank. Propane is the way to go.

Hooking up belts to the Tesla reminds me too much of Ferris Buellers Day off

 

[boulder.dude]

Trade your Tesla in for a car the supports vehicle-to-load, e.g, Ioniq5, EV6, or F150…

 

[ZenRockGarden]

I would think it'd be easier to bodge together a Vehicle-to-Load reverse electrical flow setup than turning the cars wheels into motor drives...

 

[Big Earl]

Diesel is where it’s at for standby generation. I have the Yamaha version of this Kubota Lowboy and it’s outstanding. They’re also available in higher outputs.

Kubota Lowboy II Diesel Generator - GL7000, 7 kW Standby, 6.5 kW Prime, Single-Phase, 120-240 Volt, Liquid-Cooled, Enclosed

Kubota Lowboy II GL7000 Generator - 7 kW Standby, 6.5 kW Prime, Single-Phase, 120-240 Volt, Liquid-Cooled, Enclosed Powered by a compact and powerful liquid-cooled Kubota Z478 2-cylinder diesel engine. Convenient Single-Side Service comes standard on

www.absolutegenerators.com

 

[Rocky_H]

I'm really wondering why no one has yet put in the link to the 21 page thread about this.

MASTER THREAD: Powering house or other things with Model 3

So I came home to a power outage last night, ah mountain living. As I am burning the lamp oil for light, and hating the fumes I start to wonder why I'm sitting in the dark with 40 kWh in the battery sitting in my driveway. I decided to plug a small inverter into my cigarette lighter in my...

teslamotorsclub.com

 

[davewill]

Might as well point out that you don't have to have solar to have a powerwall. It can help shift usage to off-peak if you have time of use rates, or can simply be a power backup device. There are other battery systems out there that might do the job better, or be cheaper if you're just looking for blackout protection.

 

[jcanoe]

I don't believe Tesla will sell/install the Powerwall without solar.

 

[jjrandorin]

I don't believe Tesla will sell/install the Powerwall without solar.

Tesla itself currently doesnt, but third party solar companies will (with inflated costs).

@Rocky_H I didnt link that thread because for some reason I got the impression that the OP was not interested in anything but their "car on jacks driving generators" idea. Not sure where I got that impression from though, after reading the OP again.

 

[Gaige]

It's not cheap, but much cheaper than the 60k you mentioned..

Bluetti, Jackery, Ecoflow have a lot of solutions that help and use battery backup power.

For $2-3k you can have a pretty sizable backup option, you don't need to buy their solar panels but those are an option too.

I went with Jackery for the size / weight and not that worried that it's not LFP. If you're not moving too often, Bluetti might be more bang for the buck.

I wouldn't mess with your car's electrical

 

[norazi]

Most viable thing would be to get an EV with a built in 240v inverter.... F150, Cybertruck, ioniq5?