Gadgets

[Frankenblob]

What I am hoping is that the Cybertruck will have an attachment whereby I could connect 1-3-8-15...solar panels DIRECTLY to so as to charge the battery. This of itself would be worth the purchase because anyone, provided the computer system wasn't "hacked" or goobermint shutdown the "internet"-for YOUR "safety".... could truly live off grid and hunt, fish travel....

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[ajdelange]

You will never be able to connect panels directly because they are low voltage with the voltage depending on the amount of sunlight and the battery is at much higher voltage. Thus you need something to convert the solar panels' output to a voltage that can charge the battery. There are devices you can buy today that do this. They track the PV voltage, draw just enough current to optimally load the cells (MPP = Maximum Power Point tracking) and use the collected energy to charge an auxiliary battery. When that battery has accumulated enough charge (we'll come back to this) an inverter connected to it sends 120 (or even 240 V) to the UMC and charges the car.

I have done this with a Jackery Explorer 1000 - the red and black box at the right of the picture.

It, when fully charged, can deliver 1 kW of power to the car and, thus, charge my X at about 3 - 3.5 miles per hour.

The problems are, of course
1)It it fully discharged in about an hour i.e. it, when fully charged, only holds 3 - 3.5 mile
2)It would take 4 - 5 hours of direct, full sunshine to charge it from a single panel of the size normally placed on the roofs of houses (300W) and even longer from the pair of 100W panels shown in the picture.


Thus, while my experiment was fun it clearly isn't a practical way to charge the car (though my 3.5 mile electrical "jerry can" is sometimes on board for long road trips).

There is a video (https://carbuzz.com/news/watch-this-tesla-model-3-owner-charge-his-car-with-the-sun) where the guy put 8 panels on a trailer, used them to charge a bank of lead acids and an inverter connected to those to charge his Model S. Rough numbers suggest that he'd have 2 kW available from that array in peak sun and assuming he could get 5 hours of that in a day 10 kWh per day for charging giving 30 - 40 miles per day in the S/X and perhaps 20 - 30 in a CT.

 

[Frankenblob]

You will never be able to connect panels directly because they are low voltage with the voltage depending on the amount of sunlight and the battery is at much higher voltage. Thus you need something to convert the solar panels' output to a voltage that can charge the battery. There are devices you can buy today that do this. They track the PV voltage, draw just enough current to optimally load the cells (MPP = Maximum Power Point tracking) and use the collected energy to charge an auxiliary battery. When that battery has accumulated enough charge (we'll come back to this) an inverter connected to it sends 120 (or even 240 V) to the UMC and charges the car.

I have done this with a Jackery Explorer 1000 - the red and black box at the right of the picture.

It, when fully charged, can deliver 1 kW of power to the car and, thus, charge my X at about 3 - 3.5 miles per hour.

The problems are, of course
1)It it fully discharged in about an hour i.e. it, when fully charged, only holds 3 - 3.5 mile
2)It would take 4 - 5 hours of direct, full sunshine to charge it from a single panel of the size normally placed on the roofs of houses (300W) and even longer from the pair of 100W panels shown in the picture.


Thus, while my experiment was fun it clearly isn't a practical way to charge the car (though my 3.5 mile electrical "jerry can" is sometimes on board for long road trips).

There is a video (https://carbuzz.com/news/watch-this-tesla-model-3-owner-charge-his-car-with-the-sun) where the guy put 8 panels on a trailer, used them to charge a bank of lead acids and an inverter connected to those to charge his Model S. Rough numbers suggest that he'd have 2 kW available from that array in peak sun and assuming he could get 5 hours of that in a day 10 kWh per day for charging giving 30 - 40 miles per day in the S/X and perhaps 20 - 30 in a CT.

Then I guess Elon speaking about having the "tonneau cover" a solar panel was just useless hot air?

Well, alright.

 

[TyPope]

Then I guess Elon speaking about having the "tonneau cover" a solar panel was just useless hot air?

Well, alright.

4 miles from 4 hours of a single house-sized panel would be about 20 miles after 8 hours in the sun with a Vault cover's worth of panels (assuming optimal sun and optimal positioning...)

 

[ajdelange]

Then I guess Elon speaking about having the "tonneau cover" a solar panel was just useless hot air?

Well yes for the most part but some people just love this idea.

These vehicles are subject to "phantom drain" i.e. they consume enough electricity when parked just to keep the communications and other critical stuff alive to result in the loss of up to half a mile of range per hour (12 miles of range per day). If I took my X to an airport and was away for 2 weeks my battery would be down as much as 144 miles upon my return which could be a problem if the nearest SC was some distance from the airport. Elon has claimed as much as 11 miles per day under ideal condiitions (sunny place near the summer solstice). That would be enough to cover most of the phantom drain. Under more realistic conditions it might cover half so that I would find my battery down 70 miles rather than 144. That's an improvement. Plus you have to admit its a pretty cool concept even if not an entirely practical one. Depending on what it costs I may order it.

 

[ldjessee]

Elon also discussed solar 'wings', which I am assuming unfold from the side storage when parked and gives more surface area to charge the CyberTruck with... such as when camping, etc.

 

[Crissa]

Solar systems are whatever voltage you make them to be. While the batteries my camp solar are just 12v (I just use the Mazda 3's battery) the system actually runs at 150v.


So it's just how you wire it up. And as pointed out, there's actually gain from charging the 12v system even in an EV: The car has electronics which are operating, waiting for your key, maintaining the battery, running the radios, pre-cooling the cabin, whatever.

And this can help an ICE vehicle, even. The EU-spec Mazda 3 has a clutch in the alternator to save power. And even on an older car, the drag of the alternator is greater when it has to work harder to drive cooling and radios and lights. I was able to get 1mpg from adding solar to my old Sentra ^-^

-Crissa

 

[OneLapper]

Solar systems are whatever voltage you make them to be. While the batteries my camp solar are just 12v (I just use the Mazda 3's battery) the system actually runs at 150v.


So it's just how you wire it up. And as pointed out, there's actually gain from charging the 12v system even in an EV: The car has electronics which are operating, waiting for your key, maintaining the battery, running the radios, pre-cooling the cabin, whatever.

And this can help an ICE vehicle, even. The EU-spec Mazda 3 has a clutch in the alternator to save power. And even on an older car, the drag of the alternator is greater when it has to work harder to drive cooling and radios and lights. I was able to get 1mpg from adding solar to my old Sentra ^-^

-Crissa

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