Emergency charging

[David71201]

I have seen many discussions about using portable solar panels to charge an EV while camping or on a road trip. As has been often pointed out, trying to charge the car's batteries a significant amount just isn't practical.

However, suppose you simply need to charge your EV just enough to drive a few miles. Then, even at the slow rate of charging that portable solar panels would provide, maybe you would only have to charge for a few hours. That would be preferable to calling a tow truck.

I see lots of portable solar products on Amazon and on different solar companies' websites. Is it as simple as solar panels, battery, inverter? Somehow I think not. Any advice would be greatly appreciated. Thanks.

 

[nwdiver]

That would be preferable to calling a tow truck.

Is it? I mean... unless it's planned but then that's not really an 'emergency'. ~500w of solar + an inverter is going to take up more space than a spare tire and even that could take an entire day to produce enough energy to go a couple miles....

 

[Misterbee]

How far do want to be able to go in this scenario? How far can your car go on one Kilowatt/hour? I am guessing that a Model 3 would go less than 5 miles.

Assume you have 500 watts of solar. That’s a lot of panels. If you had a battery, and if the light was just right, it would take at minimum two hours to generate one Kilowatt hour. It could work, but only as a last resort.

But if you want to do it, look for an Ecoflow Delta. Fantastic battery/inverter system that can power most things, including a Tesla. I have one, along with a matching set of solar panels, and I plan on taking it on my next Tesla camping trip. Mostly for lights and refrigeration, but yes, in a pinch, it might get my Tesla five miles down the road.

 

[SSedan]

Low rates of charge are inefficient due to the overhead of the charging system which consumes a few hundred watts right off the top of whatever you are giving the car. So at low rates you are wasting more keeping the charging system active than you are putting in the battery.

 

[SageBrush]

OP, wouldn't it be awesome if we could all pack a reserve battery of ~ 3 kWh in an out of the way place we could forget about until an emergency, and then have it available with no fuss ? That is how I treat the last 5% SoC of my traction battery.

 

[CyberGus]

Just call someone with a Cybertruck and plug your MC into their 220-volt outlet.

 

[David71201]

Thank you all for your input. The reason why I posted it is because of an incident I had. Two years ago I was visiting my mom, who has a Chevy Spark EV. I was driving it to a friend's house. When I was about 5 miles from his house, the car indicated 5 miles of battery left (which we all know is not completely reliable). I may have made it. But if I ran out even a quarter miles from his house, I might as well have been 25 miles from his house. I would have to call a tow truck. I played it safe, swung into a Safeway parking lot, parked and plugged in to an standard 110 outlet (yes, the slowest charging there is). I charged for an hour and gained 4 miles. If I had had an emergency solar charger in the car, I probably would have tried to make it to the house.

I recently purchased a used 2015 Model S 70, so preventing incidents like the above mentioned are important.

 

[SSedan]

Use NAV it will coach you to slow down or whatever it takes to make a destination.

 

[andrewFW]

OP, wouldn't it be awesome if we could all pack a reserve battery of ~ 3 kWh in an out of the way place we could forget about until an emergency, and then have it available with no fuss ? That is how I treat the last 5% SoC of my traction battery.

You're in luck!
Yeti 3000 Lithium Portable Power Station w/ WiFi Control | Goal Zero

Spoiler: it technically works but the benefits probably aren't worth the expense.

 

[Stampee]

A 6000 watt 220v generator would be great as an emergency charger, but... How to transport it is a big issue.
Stampee