Overloaded Panel: How To Load Share
Load Sharing: Between Vehicles
Unless you have a large electrical service, or a lightly loaded electrical panel, having capacity to charge several EVs at a time can be challenging. Here are some products/ideas to help.
Tesla EVSEs can load share among themselves. Whether you have the Tesla/NACS one, or the Universal Wall Connector, as long as they are the latest V3 design, they can communicate among each other. They can be programmed to only collectively draw a set maximum current between up to six EVSEs.
Enel Group makes a line of J1772 EVSEs that can load share.
The Grizzl-E Duo is a single EVSE that has two charge handles which can be bought with either J1772 or Tesla (NACS) handles or a mix to plug into two EVs. It automatically load balances between the EVs.
Load Sharing: Between EV and Appliance
If you have an electric dryer near your garage, you can use one of these products to share the 240V/30A dryer receptacle with your EVSE.
SplitVolt makes a range of products that allow you to share a single dryer receptacle between your dryer and an EVSE plugged into it. When the dryer draws current, it cuts off power to the EVSE, allowing you to charge your EVSE overnight without having to unplug and replug anything.
This inexpensive dryer receptacle splitter from Briidea works with NEMA 10-30 receptacles (they say they have a 14-30 receptacle version too).
BSA Electronics has a variety of products allowing you to share a dryer receptacle with your EVSE.
For a cheaper alternative, you can just get a Y cable. The downside is that you have to make sure you aren't running the dryer and charging your vehicle at the same time when using one of these Y cables. A Y cable is preferable to simply plugging and unplugging your EVSE and dryer from a plug since such plugs are often older and/or cheaply built and the spring contacts are either worn or will wear out with such use. Better to plug something in once (or just a few times) and don't touch it. This Y cable comes in either a NEMA 10-30 or NEMA 14-30 version.
Finally if you have an unusual situation, just do a web search for "Dryer Buddy" to see what other alternatives there are out there.
Load Sharing: Between EV and Panel
Sometimes you end up with an electrical panel that is at maximum capacity according to load calculations. In these situations, you can still shoehorn in an EVSE if you use one of these load sharing devices.
DCC Electric sells a number of UL listed devices that allow you to load share your EVSE with the rest of your panel. The DCC-10, for example, has current sensors that will deactivate your EVSE charging session when the panel hits a specified maximum load.