I live in Rhode Island, so I'm not very familiar with the state of things in New Jersey, but I suspect it's similar there. In brief, some public Level 2 EVSEs are non-networked and generally free; you just unhook the J1772 plug and plug it into your car (with Tesla's J1772 adapter, in the case of a Tesla). Others are networked and require an app, access card, or credit card to activate. The networked EVSEs are usually free in my area, but sometimes not. When they're not, you generally need to register a credit card with the network operator to pay for the charge, and the cost is usually greater than you'd pay at home, so it's seldom worth using those EVSEs. (With a Tesla, you'll have sufficient range that you seldom need an on-the-road charge, and when you do, you'll be better off with a Supercharger than a Level 2 charger. One exception might be an overnight stay at a hotel on a road trip.)
Here in Rhode Island, most of the networked public EVSEs are
ChargePoint units. One station I sometimes use is an
EVgo unit, but its J1772 plug requires no authentication; only its CHAdeMO and CCS plugs require an EVgo account.
Public charging infrastructure comes in both Level 2 (usually J1772, but some Tesla units exist) and DC fast charging (in CCS, CHAdeMO, and Tesla Supercharger varieties). (Some businesses will also let you plug into their outside 120v outlets, but that's almost never worth the bother.) For a Tesla Model 3, you can use either J1772 or Tesla Level 2 EVSEs, but for DC fast charging, you can use only Tesla's Superchargers -- at least for now. A Tesla adapter for CHAdeMO exists, but doesn't yet work on Model 3s. There's speculation that Tesla may release an adapter for CCS in North America, but so far that's just speculation. (Such an adapter exists in Europe, but European CCS and Tesla plugs are different from their North American equivalents.) The upshot of this is that you don't need to be concerned with CCS or CHAdeMO DC fast chargers; they're useless to you. You'll be able to use Tesla's Superchargers with minimal fuss -- just be sure that a valid credit card remains linked to your Tesla account. Public Tesla Level 2 EVSEs are generally free and non-networked. That leaves public J1772 EVSEs, some of which are networked and require authentication, as described earlier. Register with whatever network(s) exist near you, or near places you might want to visit on a road trip, and you should be able to use them.
You can investigate your area virtually via the
PlugShare app. This app provides crowd-sourced data on EVSEs and DC fast chargers. Entries usually note whether a unit is networked and how much it costs. The data sometimes lags reality, but to figure out with which networks you might want to register, it should be fine. Also, note that charging network operators are increasingly setting up cross-registration agreements, so you can activate a Brand B EVSE using a card or app from Brand A. I don't happen to have a link to a document that details all these arrangements, though.
So, in brief, here's what I recommend you do:
- Download the PlugShare app and register with PlugShare. Peruse your area to figure out what networks operate near you or places you're likely to visit.
- Download the ChargePoint app and register with ChargePoint. This will likely include giving them your credit card number, although you may be able to forego that if you want to use only their free EVSEs. (I don't recall if you can skip the credit card registration.)
- If some other network operates in your area, download their app and register with them, too.
- When you get your car, be sure it includes the J1772 adapter and test it so you can be sure it works. (Getting it replaced in the first few days is likely to be easier than if you wait a month and then discover it's bad.)
- When convenient, test a Supercharger to be sure your car has no faults that prevent it from Supercharging, and that your credit card is registered with Tesla.
Of course, you can adjust this list to suit your needs. If some network other than ChargePoint dominates the J1772 EVSEs in your area, register with them instead of or instead of ChargePoint, for instance. I wouldn't bother with Electrify America, EVgo, or other networks that host mainly CCS and CHAdeMO fast chargers. (FWIW, I do have an EVgo card, but I've never used it.) OTOH, if and when CHAdeMO and/or CCS adapters begin working or become available for the Model 3, you might consider buying one and registering with additional DC fast charging network(s). In New Jersey and nearby states, Tesla's Supercharger network is currently superior to CHAdeMO and CCS networks; but being able to use third-party DC fast charging networks as a backup in case of unexpected events may be worthwhile. (OTOH, the cost of an adapter is significant -- it's $450 for the current CHAdeMO adapter, for instance.)