How many watts does an EV charger use
While it runs, an EV charger draws 7,680 W, and it has no starting surge. The smallest portable able to run it is 10,000 W.
Running watts and starting watts
| Load | Running | Starting |
|---|---|---|
| EV charger, Level 2, 32 A | 7,680 W | no surge |
Source: computed: 32 A x 240 V under NEC 625 continuous load. Your EV charger's own nameplate states the exact number in watts or in amps. For the math, multiply amps by 120 V. A two-pole breaker load, such as a well pump, is the only case where you multiply by 240 V.
Smallest generator able to start it
A generator needs to handle 7,680 W, and that load must stay at 80% of its rating or below. For both jobs, the smallest common portable is 10,000 W. Every other load adds its running watts to that generator.
Other loads with an EV charger, Level 2, 32 A
| EV charger, Level 2, 32 A plus | Running | Peak at a start | Smallest portable |
|---|---|---|---|
| lights, TV and the router | 8,250 W | 8,250 W | 12,000 W |
| a freezer and lights | 8,330 W | 8,830 W | 12,000 W |
| a 1/2 hp sump pump and lights | 8,880 W | 9,980 W | 12,000 W |
| a microwave | 8,880 W | 8,880 W | 12,000 W |
| a 1 hp well pump | 9,680 W | 11,680 W | 13,000 W |
| a window AC, 10,000 BTU | 8,880 W | 10,080 W | 12,000 W |
Running watts add up, and only the largest motor start sits on top of them. A portable's starting output comes in about 25% above its running rating. The appliance wattage chart covers every load.