Solar charging a plugin hybrid car

Oh boy, that would require knowing how many watts it takes to run your car 50 miles. I'll be back..
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The most efficient cars, with the lowest energy consumption (Combined) are: Hyundai IONIQ Electric - 248 Wh/mile (154 Wh/km) Tesla Model 3 Standard Range Plus - 253 Wh/mile(157 Wh/km) Tesla Model 3 Standard Range - 257 Wh/mile (160 Wh/km)

Ok, so, 248 watt-hours/mile (converted to 12v) = 21 amp-hrs/mile
21 x 50 miles = 1,050 ah

1050 ah / 4 hours = 262 amps of solar.

No. 262 amps of solar @ 12v is out of the question.
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I could be totally wrong. Someone will let me know. As far as your 'cost effective' comment, solar is not always about cost effective, it's about quiet convenience.

If you can achieve 240 volts at 40 amps with solar then it would work.

Not practical. Even charging an electric car on 120 volt household current is impractical.

A Tesla model 3 is about 250 Wh per mile. For every 250W panel you would get about one mile per hour of sun (assuming full output). With flat mounted panels and losses it is probably more like 0.7 miles per 250W panel per hour. Assuming you could put about 2500W of solar on the roof, that would be 7 miles per hour of charging, or 28 miles in 4 hours of driving.

Given how incredibly energy inefficient a motor home is, I am not sure there would be much point to this.

Gjac wrote:
I have read most of the solar and li battery threads but have never seen how they would ever be cost effective in the way I camp. Having said that I was wondering if solar panels on top of a MH be effective at charging a plugin hybrid or electric car while towing? For example would 4 hrs of travel in sunlight be enough to put 50 miles back into the car's battery? How much solar would be required to do this? Or is this jut not practical?

Is there a reason you cannot charge before you leave and after you arrive in addition to the 4 hour drive? Solar panels work all day.

Otherwise yes you are looking at close to 2000+ watts of solar on the MH. You would not be the first.

I would expect you would be topping up the toad every day as power is available. Probably also expand the MH house battery to save up the solar power for charging the toad faster when needed.

If you have a 1000w (nominal rating) of solar panels, it should generate around 4kwh/day.

If the above 0.25kwh per mile is correct, your solar system will provide around 16miles of range per day if there are no losses. Add in losses and you might be looking at 12-14miles per day.

If you have a smaller or larger solar array, it scales up or down accordingly.

Keep in mind unless they offer a DC to DC charger, you are going to need a charge controller to take the solar output and put it in a large battery bank, then an inverter to convert it to AC, so you can plug the car into an outlet...that's a lot of conversions each with losses.

Of course, this assumes, you don't use any of the 4kwh for house loads in the RV. If you have a residential fridge, watch a few hours of TV and light usage, you could easily eat up 25-40% before anything goes to the car.

Hyundai put a 205W panel on top of their Sonata hybrid, and they said it gives around 700 "free" miles a year... or around 2 miles per day.

All that being true, my electric scooter gets 20 miles out of a mere 10 amp-hour battery making solar quite feasible. Which is why solar is all I’ve been using.

(Fireproof long Johns in place.)

time2roll wrote:

Gjac wrote:
I have read most of the solar and li battery threads but have never seen how they would ever be cost effective in the way I camp. Having said that I was wondering if solar panels on top of a MH be effective at charging a plugin hybrid or electric car while towing? For example would 4 hrs of travel in sunlight be enough to put 50 miles back into the car's battery? How much solar would be required to do this? Or is this jut not practical?

Is there a reason you cannot charge before you leave and after you arrive in addition to the 4 hour drive? Solar panels work all day.

Otherwise yes you are looking at close to 2000+ watts of solar on the MH. You would not be the first.

I would expect you would be topping up the toad every day as power is available. Probably also expand the MH house battery to save up the solar power for charging the toad faster when needed.

I don't go to FHU CG's so no way to plug in. I am just trying to think ahead, I know it is just a matter of time until gas is over $4.00/gal. I have a hybrid car now that gets over 40 mpg's I was thinking about a plugin hybrid that can be towed flat. Where I live electric costs are very high 23 cents/KW so when gas was $2.00/gal it was much cheaper to stay with my current car. At $3.40/gal is the break even point. I am told electric costs when traveling are between 22-45 cents per KW which is more costly than home charging. Like I said in my OP I have no need for solar on my MH because I always run out of water before battery power. But with the costs of solar coming down I was thinking solar might make sense for a plugin hybrid even at home when not camping.

OK. The solar panels can be used to charge a plug-in vehicle. If the panels are on the MH, as mentioned in the OP, you can charge that vehicle every single day you are camped as long as the sun is on the roof of the RV. May need to use your ample house battery as a buffer and if it gets depleted the solar would charge that too. Yes it all works to the degree of commitment to the project.

Our fuel is already $4.25 a gallon. I also have 3 kW solar on my home that paid for itself in five years.