SolarEdge is making a home DCFC

[chl]

24kW / 240v = 100 amps, so a 125 circuit minimum. BUT....what if it only pulls 80 amps from the grid and combines that with solar/additional battery storage for a max supply of 24kW? If it pulls 19kW from the grid then it only needs 5kW of solar to supply the stated amount. Then it would easily work on a 100amp circuit like the current FCSP.

Given that it isn't slated for another year, I'm not surprised that the details are limited. I couldn't find anything else on their website when I glanced. The article is confusing here:

" In addition, the EV battery can function as a large home battery storage solution of up to 50kWh, both on and off grid, enabling homeowners to use their EV to back up their homes for extended periods during an outage (V2H). "

It seems odd that there would be a limit on the amount of stored energy that could be supplied. Most EV's on the market are larger than that. Additionally, if that's the case (which I doubt), what is the rate that it can supply it?

I'm intrigued enough to keep an eye out for more news.

I think one should size the grid circuit on the assumption, worst case scenario, that the solar contribution is zero - it could be off-line for some reason.

Yes, where did the 50kWh come from?

I have seen other companies advertising upcoming V2H/V2G systems as well, with sketchy details...if you Google V2H or V2G you come across them.

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[chl]

I personally wouldn't worry about charging at 80 amps vs 30 or less. The Lightning battery is so big that you are picking between slow and slower charging.

Consider most consumer lithium packs that are in cell phones, laptops, power tools etc. are designed to be charged 0-100% in about 1 hour. Despite having no thermal regulation, being charged to 100% regularly, and being designed for maximum energy density over longevity, you can still get around 1000 cycles out of these batteries before they are done.

Even at a full 80 amps it would take 8 hours to charge a Lightning, so you are essentially charging your lightning cells 8x slower than the scenario above, without all the aforementioned drawbacks that consumer lithium batteries encounter. You'd have to exclusively DC Fast Charge in hour long sessions to emulate the stress that is put on lithium batteries in other applications.

Tesla seems to predict that their batteries will last 500,000-600,000 miles, which would be about 1700-2000 cycles on a 300 mile battery. Seems achievable if the thermal and BMS systems do their job, charge to less than 100%, and excessive DCFC isn't used. I'd be pretty happy with a 500,000 mile battery cause it would probably last the life of the truck. So if I ever have an electrical panel with 100 amps of spare capacity, I'll happily install my Charge Station Pro and charge at 80 amps.

Yes, fast DC charging puts the most thermal stress on the battery.
EV batteries have lasted longer than the predictions, and calendar degradation is not as bad as once thought.
Heat/temperature are the biggest issue so thermal management is critical.

The higher the current the higher the temperature no matter how big the battery is, which is why manufacturers always say to limit fast charging to prolong battery life - fast charging is higher current and higher temperatures in the battery will result.

So 30A will put less thermal stress on the battery than 80A just based on the physics.

Add to the charging induced thermal stress the ambient temperature if one lives in a hot climate.

How much that 80A vs 30A would affect the lifespan, I can't say for certain, maybe it would be negligible. But if you have the time, slow down the charging rate, especially if the ambient temperature is above 70 degrees. Also, let the battery cool down after use before recharging.

You get 8 years, 100,000 miles of battery warranty with the Lightning and pretty much all other EVS. That's a warranty that the battery won't completely fail or fall below 70% of capacity within the time and mileage limits.

But there is a gradual decrease in capacity over time even before you reach the limits, mostly dependent on the thermal stress from charging/discharging and the ambient conditions.

So one thing that might not have been considered the calculation is the gradual decrease of range over time to reach that 500,000 miles mentioned?

According to Car and Driver Tesla's Model S maintained 90% of their battery capacity, a 10% loss, after 150,000 miles in one crowd-sourced study. A model S lost 6% after the first 20k miles, but then didn't lose more until 40k miles 2 years later.

https://www.caranddriver.com/research/a31875141/electric-car-battery-life/

Another thing in the calculation is the "300 mile battery" assumption.

For longevity one wants to not go above 80% or below 20% capacity.

That extended range 320 mile battery in the Lightning is the EPA estimate based on a 100% charge multiplied by a .7 fudge factor so EV drivers don't over-estimate how far they can go on a road trip and run out of juice.

https://www.greencars.com/greencars-101/how-epa-estimated-range-is-calculated

If you only charge to 80% and discharge to 20% and you'll have to reduce the range accordingly, probably down to around 200 miles of range under ideal circumstances.

The real-world range is going to depend mostly on the load - pull a trailer on the highway will cut the range substantially, for example - but also the ambient temperature. Very cold or very warm will reduce the range in real life, optimum temperature is 70F, despite the on-board battery heaters and coolers.

Run the AC or heat - cut the range.

One poster here or on another forum travels from east-to-west coast pulling a trailer behind him and fast charges every 100 miles, except for when he stops overnight then he L2 charges.

So that 320 miles became 100 miles in real life very quickly.
And reaching 500,000k miles is 3 times more cycles.

Still, the Lightning should be adequate for average use and last the 8 years/100k miles (10years/150k mile in CA) even adjusting for those factors I'd bet.

Tesla is aiming to get a 1 million mile battery one day!

 

[chl]

I thought relying on DC fast charging was not exactly healthy for the batteries. I thought DC fast charging was only when you need quick charges like on long road trips.

Yes, it's the thermal stress that is the culprit.
The slower the charge the less thermal stress.
So if you don't need the speed, don't fast charge.

 

[chl]

We are getting close to testing the cells, so I will be able to quantify it...but I won't be able to share the results. I think the timeline is to dismantle a couple of modules is late July or early August. If you see me suddenly selling my truck, you will know.

OK. Too bad you can't share the results here. Will they be published anywhere?

 

[intensifi]

I am signing up for the Enphase integration unit which will support V2H, etc.

EnPhase will be following the newer V2H standard adopted by IEEE.

Question remains if Ford will update the software on the existing trucks or only support the Sunrun unit for the ‘22-‘24 Lightnings. I have my doubts.…

 

[Yellow Buddy]

I’m not concerned with 24 kw DC versus 19.6 kw AC that’s converted to DC in the truck. I see no benefit at this point.

The benefit (if you have solar) is the conversion loss. Instead of converting it from DC to AC and then back to DC, you can go straight DC to DC.

I haven’t reviewed the documents but I know my (older) system has nearly a 25% loss between transmission distance and the inverter conversion. I believe I saw somewhere another 10% through the Ford charger and into the truck battery.

Even if it saves only that 10% conversion back it can be a significant benefit if you drive enough. For me, I’m utilizing roughly 9MWh/year for the Lightning alone and roughly 35MWh/year between all 3 cars so there’s a potential payback period

 

[scottf200]

I thought relying on DC fast charging was not exactly healthy for the batteries. I thought DC fast charging was only when you need quick charges like on long road trips.

Wait ... this isn't "fast charging" tho. This would be DC slow charging. That is way higher kW ... think 70+

Your battery always gets charged with DC with the difference the AC->DC inverter in your car coverts it to DC or the AC->DC inverter at the charging site converts it before it gets to your car.

 

[Frankhpns]

If I read this correctly, it will be a 24kW DCFC that can pull straight from solar/battery/grid and also allow V2H and V2G. I don't really need to charge that fast but wow.

https://www.businesswire.com/news/h...rectional-DC-Coupled-Electric-Vehicle-Charger

We have a 30MWH per year solar system and have net metering here in Florida. I set the charge time to electric company TOU on the truck to reduce charge cost. A direct solar to truck system would not do us any good.

 

[Runaway Tractor]

Calling it DCFC is lying for the purpose of marketing. It's DC, but it is not FC. One is not required for the other and kWh is kWh no matter the source. It doesn't matter if the AC power is converted to DC using the onboard level 2 charger, or offboard on this charger mounted to the wall of your house.

The advantage of this system is the ability to send a solar system's DC power directly into the vehicle without being converted multiple times. It is certainly more efficient. And it also enables (theoretically if they do it), that high voltage DC flowing backwards to the house's solar inverter. This would let your vehicle battery literally and properly act as a power wall working in the loop with your other solar, inverters, storage, etc.

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