A month ago, an unexpected road closure left me driving into a rest stop with "0 miles" indicated. Explaining the problem to a maintenance man, he gave me permission to put on enough charge to reach a nearby SuperCharger. But I had to park on the grass which was not optimal. So this is how to prepare to use your 110-120 VAC, EV portable charger in an emergency.
First carry a 15 A rated, long extension cord. For example:
Or better yet:
The next problem is finding an exterior outlet:
The maximum current from a typical NEMA 5-15 outlet should only be 12 A. But sometimes, you need to derate the charge rate because of other loads on that circuit. Start at 8 A and see what voltage the car reports. Then up it to 12 A and see the voltage drop. If large, go back to 8 A. My Model 3, 250 W/mi, will typically see:
Always try to have enough reserve, typically 40 mi, to the next fast DC charger. Then drive checking the indicated range and miles to charger:
First carry a 15 A rated, long extension cord. For example:
Or better yet:
The next problem is finding an exterior outlet:
- Tennesse Rest Stop I65 - two were found but only one was practical:
- Alabama had rebuilt the rest stop so this was the best:
The maximum current from a typical NEMA 5-15 outlet should only be 12 A. But sometimes, you need to derate the charge rate because of other loads on that circuit. Start at 8 A and see what voltage the car reports. Then up it to 12 A and see the voltage drop. If large, go back to 8 A. My Model 3, 250 W/mi, will typically see:
- 8A - ~880 to 960 W/hr, about 3-4 miles charge per hour
- 12A - ~1,320 to 1,440 W/hr, about 5 miles charger per hour
Always try to have enough reserve, typically 40 mi, to the next fast DC charger. Then drive checking the indicated range and miles to charger:
- +40 miles - keep up with traffic
- ~30 miles - become the slow poke, follow moving vans
- ~20 miles - become the *sshole and use the minimum speed with flashing emergency lights
- ~10 miles - find a safe place for the tow truck to pick you up