Use of existing and available 240volt outlets is very common for Tesla drivers. I do it all the time. The key thing is to have a correct adapter for the outlet and, most important:
only draw 80% or less of the outlet's rating. Therefore, if it's a 30 amp outlet, don't draw more than 24 amps and only draw 16 amps on a 20 amp outlet, etc.
Unfortunately as far as I know, only Tesla makes it easy to do naturally.
With Tesla cars, you can manually limit the maximum charging current that the car will pull or the charging stations limit the current correctly for the plug you're using.
Without a Tesla, it may be a bit harder because your carmaker won't supply the necessary equipment, but it can be done. You'll need to use the EVSE (charging station) to tell the car the maximum current that it can draw. If it's a 30 amp outlet, you'll need an EVSE that tells the car to max out at 24 amps.
Here are a few options for doing this:
1) The most complete travel solution is to tap into the Tesla supply chain and get:
- a Tesla Mobile Connector (
https://shop.tesla.com/product/corded-mobile-connector)
- a Tesla_plug-to- J-1772_receptacle adapter such as QuickCharg Power's JDAPTER STUB (
https://qccharge.com/collections/jdapter-stub™-tesla-station-adapter/products/jdapter-stub).
- Tesla's "NEMA Adapter Bundle" (
https://shop.tesla.com/product/nema-adapter-bundle) or individual adapters if you don't need the full kit (
https://shop.tesla.com/product/gen-2-nema-adapters).
A kit consisting of the 3 items above will let you easily and safely use pretty much any 120 or 240 volt outlet as well as a Tesla Destination Charger that you may come across in your travels.
2) Maybe an easier way to take advantage of Tesla's products is with Tony Williams' "JESLA JR". This is a Tesla Mobile Connector with a J-1772 connector replacing Tesla's connector. The Tesla Mobile Connector has different 120 and 240 volt adapters available. The Tesla Mobile Connector, then decides how much current to allow the car to draw, based on the connector type. If you plug into a 30 amp outlet (eg. NEMA 14-30 or NEMA 6-30 dryer outlets), you'll only draw the safe 24 amps. If you use an adapter for a 20 amp outlet such as a NEMA 6-20, you'll safely only draw 16 amps.
Solution 2) may be a bit cleaner to plug in to a non-Tesla but you won't be able to use Tesla Destination Chargers that may be available.
3) Buy a mobile charging station such as the Clipper Creek LCS-30 (
https://store.clippercreek.com/level2/level2-20-to-32/lcs-30p-nema-14-30) that will work with a 30 amp dryer outlet and is a UL approved option. For a 20 amp outlet, you'll need a Clipper Creek LCS-20 (
https://store.clippercreek.com/level2/level2-12-to-15/16-amp-evse-14-50-plug).
A quality J-1772 extension cable such as
https://qccharge.com/collections/jlong-j1772-extension-cables/products/jlong may be helpful if there's a long run from the outlet to where you can park.