Modified Sine Wave Inverters - EV Charger safe?

[thingstodo]

Has anyone tried to run a Tesla charger off a modified sine wave inverter? I don't want to damage my on-board charger, of course .. but I'm cheap!

All the discussions I can locate discuss pure sine wave inverters, which of course work fine.

I'm looking to .. hoist .. 5 kWh of 12V battery pack plus a cheap $400 chinese 10 kW 220V 50 Hz inverter in the back of my Model Y to help with my 'charger anxiety'.

In Saskatchewan, Canada we have sparse coverage of the highways with fast charging. Presently most available chargers are on 5 of the main highways and are spaced 100 - 150 km apart. No support at all on secondary highways.

My model Y Long range does 400 ish km in nice weather, about half (200km) that at -30C to -40C when sitting outside overnight.

It is stressful (for me) to drive an EV on a weekend trip for my grandson's hockey tournaments .. to a small town in the middle of nowhere (over 100 km from the nearest Tesla supercharger or Electrify Canada fast charger) .. relying on a single fast charger to be operational.

5 kwh is only going to get me another 10 km when it's cold, but I should be able to locate 120V (preferably higher) within that 10 km .. or make it to the charger I was trying to get to but didn't quite make it, or maybe get to an alternate level 2 charger.

A pure sine wave, name brand, 10 kW inverter is over $1200. I'm investigating the cheaper option!

[Zieg]

Also interested in this for charging my racecar at the track.

Have you looked at generators at all? They can sometimes be found with 240v outlets. Some have inverters, the cheaper ones don't. From my reading, the 'cleanliness' of the output can be expressed in a percentage of 'total harmonic distortion' or THD. No idea how picky a charger would be, though.

At least the generator has the added benefit of being useful for other situations?

[johu]

I suspect the charger won't care as it just rectifies and smoothes whatever comes in

An 11 kW generator would be much heavier than 5 kWh of batteries and it's fossil

[thingstodo]

I have a much smaller generator and I don't doubt that it will work fine. It's only 1800 VA .. but it kinda leaks a bit of oil and is generally dirty. I'd rather not put it in the back of the Model Y.

From the on-board charger teardowns that I have watched from various locations on youtube, it appears the onboard chargers are all electronic with no transformer stage to care about sine waves or triangle waves or square waves.

I'm just being a bit paranoid and asking everywhere that I can ask!

I figured that if ANYONE had tried it .. it would be Damien or someone else on this forum

[johu]

Oh yeah, it surely doesn't have a mains transformer or it'd be enormous! It's a switch mode supply with PFC. You could even supply it with DC voltage.

[evMacGyver]

You could even supply it with DC voltage.

I tried with Mitsubishi charger, but it measure input voltage and was not happy with DC I bet it would be just fine with non-sine supply, even bit dirty H-bridge 50Hz might be just fine.

[Zieg]

@thingstodo have you tried it yet? I'm curious how the car (and EVSE) reacted to the MSW inverter. I've been reading in some places that the charger might have trouble with a MSW input and cause it to heat up or pass on some harmonics to the battery. I have no idea if there's any truth to any of that, though.

[E46Driver]

I'm also interested in this. Been contemplating it for over a year. Used 10kW gasoline generators can be found relatively cheap around Edmonton. But I've been too chicken to try it with my TSM chargers. I've already had 1 die (I think the internal CAN-BUS card fried).

The climate on the prairies, and spread-out habitation is not conducive to EVs. Stripping down a portable generator to its most minimal components provides a small sense of security. So @thingstodo, I'm very curious how you make out with this plan!

[Pashko]

I'm charging my cars (Kia soul EV and verity of Nissan leafs, from 2011 up to 2020) without any issues on modified sine wave. Biggest problem is a start up, but after it started up it works without much issues. Even my inverter is "5000w" unit, sometimes starting a regular 1250w EVSE can be a problem. Sometimes it's just works, sometimes you have to plug it in few times since it's tripping protection on the inverter. HF inverter most expensive one from harbor freight (around 500$).

[Pashko]

Oh yeah, it surely doesn't have a mains transformer or it'd be enormous! It's a switch mode supply with PFC. You could even supply it with DC voltage.

I would test it out in a heartbeat, but I'm sadly too dumb to figure out how to fire up EVSE on DC. It's current detection circuit have to be modified to be able to see DC current and don't trip error. All OBCs what I seen and taken apart was been switching power supply based so I think DC EVSE will work on any car around here, at least all what I seen. If you can help me out to figure out how to modify/build DC compatible EVSE, it makes my life much easier and I'm gonna be happy to post my results here.