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Solar panels to EV charging

4800 Views 57 Replies 9 Participants Last post by  electro wrks
I'm looking to charge a 144 volt Lifepo equipped EV with solar panels, DC to DC. I've been reading old posts related to this but nothing directly about how to do it.
Recently, I read that a Zivan NG3 will run on 100 to 200 volts DC and have an email in to the Zivan dealer to confirm that, no answer yet. That would seem like a great solution.
Has anybody done solar to EV charging or feel willing to share some ideas?
Thanks Allan
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Okay, good point. I've used that "semi-trailer of solar panels" example before with people who wondered about solar powered electric cars. But that's what it would take to generate the power that the car uses at the same rate as the car is using it.
The person who I'm researching this subject for lives in New Mexico and has been a solar contractor for decades. He has access to plenty of hardware so it might make enough sense in this case. But I see your point. Thank you!
When you charge your car with solar power for those short trips, are you converting it to AC and then back to DC to charge? Or do you have a DC to DC setup? If the latter, I'd be interested in what sort of hardware you use. My friend in New Mexico is entirely off grid so is real interested in DC to DC.
1. Which model of electric car does your "friend" have and

2. why is he using a middleman on this forum that appears to know less about solar systems (like MPPT) than he should?
He needs to charge the truck as if it was on grid because it will need to be able to get charged on the grid, if only when it's at the neighbors. Loaded, it may only make a one way trip into town.

All of his household appliances run off the inverter. The truck is just another 240VAC or 120VAC appliance that has to be compatible with the components of the offgrid system.

Most of all, it cannot damage the offgrid system or there's no water coming out of the well. It's not something to fuck with, as we say in engineering.

For offgrid, the only cost of inefficiency is a larger solar collector.

For an EV, it's just extra charging time.

You don't have a case for DC-DC here that I can see that isn't fantasyland blue sky stuff.
One thing you are casually ignoring.

The solar system you propose, with a 144VDC car as an integral part of it will fail county electrical inspection..."high voltage" is anything over 48V, iirc.
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@cricketo - you can cowboy all you want but what you are suggesting makes the EV an integral part of the stationary offgrid system.

Being over 48V, that means it becomes part of the installation inspection and has to meet code. A plugin EV is not subject to inspection that stops at the electrical socket because it's an appliance and not part of the system.
I really fail to see the logic you're applying. If it's not hard-wired, then it's not an integral part. Would a vehicle integrated via CHAdeMO be an integral part too ?
I already addressed that.

A dedicated DC charger, like your Chademo offboard charger, is an approved device that's hardwired and its installation has to be signed off. A 50 amp AC socket is an approved device. An EVSE is an approved device. A Tesla wall box is an approved device. All set a limit on what current the car can ask for and are aware of the circuit limits to which they are wired.

These devices demark the power system from the plugin appliance. An EV or welder is an appliance.

A storage battery for an offgrid system is integral to that system by design. That needs approvals, PE signoffs, etc. The fact you put wheels on it changes nothing if your offgrid power system doesn't work without it. You can't extend the system without approvals unless there's a demarcation device there.

And if you say you can disconnect it -- that means of connection and disconnection has to be signed off because of the voltages involved. There's no Chademo box that got signed off -- you using an Arduino to do Chademo signaling into a stationary offgrid high voltage system would get you a red flag from the county. No different than adding a branch circuit. That EV is a branch circuit, not an appliance, in your scheme.
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That's not how an EVSE works. You can't limit the available power. If you only "allow" it with 500 watts the car/EVSE is still going to take whatever it's going to do. Or if there really is only 500 watts available, something is going to fail or fault out.
The EVSE limits the current to the car. My Bolt EV is limited to 12 amps. My Flo is limited to 32 Amps. My Tesla wall "charger" is limited as well. If the car asks for more current, the EVSE sends this to the car: 🖕 and negotiates the max the EVSE is set to allow.

Tesla got clever and incorporated identification in its plugs and varies that limitation.
Easiest to just charge at 1000W.

You're offgrid, which means going into town once every week or two. More than that and...what's the point?
That's a nice reference - thanks.

However, it does not apply to the pickup truck being used as an offgrid storage element:

"The scope of Article 706 informs Code users that this information applies to all permanently installed energy storage systems."
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