I have a ~500lb 12kw diesel generator that is a back up of my hybrid solar battery back up system. I hooked the Model 3 up to it on the 240v outlet and in one hour got 3% (9 miles).
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Using a generator to Charge Tesla 3 in a pinch
- Thread starter ChileKid
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eprosenx
Active Member
Yes, I suspect you could without any issue. I have used my Tesla to help load bank a friends similar home generator (i.e. put max load on it to prove it works).
I would try it out before you need it just to make sure!
Also, do you have a way to easily monitor load on the generator?
I might consider getting a Sense Energy Monitor so you can track your usage in real time to ensure you don't go over.
I came to the same conclusion. I have a five year old Honda EU3000is that has flawlessly and economically powered my boiler, refer, video, desktops, modem & router (plus a few lights) during sometimes days long outages at below freezing temperatures. At first, I thought I might use it to charge our Model 3 as well, but why? We have a Supercharger less than ten miles from home that has lost power only once, and that was during a large regional outage. When a storm is forecast, I make sure to charge to at least 80%, which will more than meet my needs for a few days of driving within the local area. For me, using a generator to charge the car is a solution looking for a requirement. Now, if I were able to use the car as a back up "generator"....but that's another thread(s).
I see the OP hasn't been back to answer any questions. Since he mentions the generator has a 240V outlet, I'm thinking he's using a non-inverter generator, since only the most expensive inverter models have a 240V outlet. Besides the non-grounded issue, I'd be concerned about the stepped wave and the voltage fluctuation of the generator.
And as others have mentioned, an inverter generator like the Honda running at constant 1600watts, will add about 6 miles/hr. A gallon of gas is good for about 4hrs of runtime, so maybe 24miles for $2.40, or about 10 cents/mile. Not too bad, but alot of work for the lil inverter generator.
As for a wholehouse standby generator, I once had a power outage, and I forgot that my Volt was connected, and discharged, so it was recharging on the generator. Since I use LP out of a 200lb tank, it's quite expensive to charge an EV off a LP generator! Now with the Tesla, I'll be sure to unplug if there's an outage, and just use the supercharger 10 miles away. Of course, if that's out, then all bets are off! I may actually have to pull out the 2000w inverter generator.
And as others have mentioned, an inverter generator like the Honda running at constant 1600watts, will add about 6 miles/hr. A gallon of gas is good for about 4hrs of runtime, so maybe 24miles for $2.40, or about 10 cents/mile. Not too bad, but alot of work for the lil inverter generator.
As for a wholehouse standby generator, I once had a power outage, and I forgot that my Volt was connected, and discharged, so it was recharging on the generator. Since I use LP out of a 200lb tank, it's quite expensive to charge an EV off a LP generator! Now with the Tesla, I'll be sure to unplug if there's an outage, and just use the supercharger 10 miles away. Of course, if that's out, then all bets are off! I may actually have to pull out the 2000w inverter generator.
GregBallantyne
Member
I believe I can charge my car with my generator, but I haven't actually tried doing that. I have a larger generator, that puts out 7500/9000. I use a 30A 240V take off from the generator to power the sub-panel in my barn, which can feed power back to the house main panel, when grid power is out. My Tesla charges from a NEMA 14/30 outlet supplied by the barn sub-panel. So I could isolate the barn from the house panel, charge the barn panel with the generator, plug in the Tesla as usual, and charge the car. However, assuming no grid power would prompt the generator car charging, there would be no power left over for the house panel. If grid power is available, I would have no reason to burn 5 gallons of gasoline to charge the car.....
So I probably could do it, but most likely never will.
So I probably could do it, but most likely never will.
Chuq
Active Member
You *can* use a generator without an issue! Here is an experiment run by the TOCWA people in Western Australia:
EV charging with diesel powered ChargePod skid – a solution for locations with inadequate power – Tesla Owners Club Western Australia
10 EVs (9 of which were Teslas) charged an hour at a time from a "Chargepod" built from a diesel generator and a 50kW Tritium charger.
The page above details the experiment. The Chargepod is now located at a service station at Jurien Bay (220 km north of Perth) - PlugShare - Find Electric Vehicle Charging Locations Near You
EV charging with diesel powered ChargePod skid – a solution for locations with inadequate power – Tesla Owners Club Western Australia
10 EVs (9 of which were Teslas) charged an hour at a time from a "Chargepod" built from a diesel generator and a 50kW Tritium charger.
The page above details the experiment. The Chargepod is now located at a service station at Jurien Bay (220 km north of Perth) - PlugShare - Find Electric Vehicle Charging Locations Near You
An eu2000i will charge a Model 3 at 12A... https://www.amazon.com/gp/product/B07F4R7BDL/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Even if I could, I wouldn't feel comfortable connecting the generator directly to my Tesla. I have a manual transfer switch for my entire house, so I'd fire up the generator and go through the exact same breaker(and Juicebox) that I normally use. Even if the science disagrees with me, I would never want to hook directly into a generator. As other things in the house are turning off and on, I wouldn't want the variation in electricity to hit the car.
eprosenx
Active Member
Hrm, I would have no issue going from a generator directly to the Tesla. Going through the house panel with a transfer switch is no different and in fact exposes you to weird voltage fluctuations from other household devices starting and stopping such as you describe.
A nice inverter generator like the Honda ones is probably great, but even non inverter ones are probably decent for car charging.
Honestly, car charging should not be a very sensitive load. I have not seen a block diagram, but I suspect all the car control computers run off the 12v system which has a nice smooth power supply that is smoothed by the lead acid battery. And the “car charging” itself is just a pure rectifier there makes high voltage DC. There are not really any horrible penalties I can think of to having fluctuations in that DC power (which by the way can be smoothed by capacitors if needed). Other than surges and spikes frying rectifier electronics, I just don’t think EV charging is really that bad a load for running on a generator.
The Tesla will ramp slowly into its current draw and so it will be pretty gentle on the generator.
Of course it is at your own risk since that is what Tesla says, but I just don’t think it has been an issue.
I see both sides of it. There may not be a right or wrong.
Anything that is plugged into a generator directly will cause the generator to fluctuate with the power it gives off(you can always hear it in the generator). If you go through your house panel you can choose what not to use. To play it safe you can switch off specific breakers. I'll never understand why people feel the need to wash/dry clothes and use the dishwasher in an emergency anyway.
Anything that is plugged into a generator directly will cause the generator to fluctuate with the power it gives off(you can always hear it in the generator). If you go through your house panel you can choose what not to use. To play it safe you can switch off specific breakers. I'll never understand why people feel the need to wash/dry clothes and use the dishwasher in an emergency anyway.
I happen to have a Generac GP8000E gasoline generator (8000 watts running; 10k starting) in the garage that we bought after Hurricane Sandy, with an L14-30R twistlock receptacle on it.
My thinking is that, in the event of a major, extended catastrophe (ala Sandy, where I had no power for 9 days and most of the surrounding area had no power either), I'd like to be able to charge from it. That should let me add about 22 miles of range per hour to Model 3. 5 gal of fuel typically runs that generator about 8 hours, so I should be able to put 176 miles of range on it with one tank of fuel.
I need to pick up a NEMA 14-30 adapter for my mobile connector and an L14-30 to NEMA 14-30 adapter to test it out, but as a Plan C, I think this'd work in a pinch. Anyone see a reason why it wouldn't?
My thinking is that, in the event of a major, extended catastrophe (ala Sandy, where I had no power for 9 days and most of the surrounding area had no power either), I'd like to be able to charge from it. That should let me add about 22 miles of range per hour to Model 3. 5 gal of fuel typically runs that generator about 8 hours, so I should be able to put 176 miles of range on it with one tank of fuel.
I need to pick up a NEMA 14-30 adapter for my mobile connector and an L14-30 to NEMA 14-30 adapter to test it out, but as a Plan C, I think this'd work in a pinch. Anyone see a reason why it wouldn't?
I think you are underestimating the fuel consumption of EV charging on a generator. Sure, you can run for 8 hours on 5 gallons of fuel, but it's going to have to work a lot harder and therefore burn more gas if you're charging a car. Don't expect more than 20-25 miles of range per gallon on a generator.
Even that is 100-125 miles. More than plenty in a lights-out-bunkering-down situation. Either way, my hope is to never use the generator. And even if I do, I owe the car charged whenever I’m home, so it “should” have a full battery. If it doesn’t, I can get enough to get out of the state with one run of the generator.
All good - I think this’ll work as a very alternate plan.
If it's not an inverter generator, load variations can cause the generator speed to change and therefore the line frequency. Tesla vehicles used to be very picky about frequency stability, so a Classic Model S, for example, would soon stop charging on a generator. I don't know how picky a Model 3 is these days.
It’s completely unscientific, but I’ve used a kill-a-watt against my Generac and it’s fairly steady unless a heavy load (ie furnace startup) kicks in and sags the line a little.
That said, I’d expect to isolate the other loads and just dedicate the generator to charging the car for a few hours. My typical cycle (at least in Sandy) was 8 hours on, 8 off. I’d use one of those “off 8” cycles for charging.
At least, that’s how my peabrain has the hypothetical situation penciled in.
I own a four year old Honda EU3000IS inverter generator that I run under load every few months for about an hour to keep the battery charged and the fuel fresh. One challenge I have had in the past was finding a suitable load bank, usually a 1500 watt electric heater blowing heat down my driveway--a waste. No longer. I now have an enormous load bank called a Tesla sitting in my garage. This is a win win. I can now do periodic PM under load (15 amp/NEMA 5-20P) and avoid wasting the fuel used by putting a few miles on the Tesla. BTW, with a Supercharger only a few miles away, I don't anticipate having to use my generator to add miles during an all too common power failure in my rural neighborhood.
If you don't want to try to do double adapters like that, the company EVSEAdapters makes really good 3rd party adapters for the Tesla UMC. They plug right into the electronics box of it and keep the temperature sensor in the plug. Here is the one for an L14-30.
L14-30 Twist-lock Adapter for Tesla™ Model S™/X™/3™ Gen 2 – EVSE Adapters
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