Level 2 Chargers and Energy Management Systems

Question

I have 100 A service in my home; installing even a 40 A circuit for a 32 A level 2 charging station would put me razor-close to the safety limits of the service (as determined by a licensed electrician); and getting an upgrade to 200 A service is prohibitively expensive.

However, there exist systems which, as I understand them, are designed to alleviate the strain of a level 2 charging station on a 100 A service by either throttling back or (more likely) turning off the charging circuit in the event that total service to the house exceeds 80% of the rating.

I am content to let the electrician judge (and the permitting agency, if necessary) judge whether these things work in terms of protecting the wiring of the house.

My question here is: Are these things safe for the vehicles and charging stations themselves, i.e., any hidden gotchas (damage to or reduction in the life of the battery, maybe?) or reasons to expect they don't work? Anyone have any relevant experience with them?

Note: Not to be confused the kind of energy management system that goes inside a vehicle, such as an RV.

This is NOT intended to be a shopping question-- the following link is provided only as examples of what I am talking about.

Answer 1

You will not need a service upgrade to charge an EV.

TLDR: will the linked unit damage the battery? No. Costly electronics (the onboard charge unit) on the car? Maybe. Do they not work? They work but are unnecessarily costly, brutish and inelegant.

The good ones are perfectly fine for the vehicle. That isn't one, it's a primitive load-shed device better suited for a hot tub than an EV, Since it's doing it the hard way, it's unnecessarily costly. You could buy a top shelf EVSE+EVEMS for less than that thing alone, e.g. Wallbox Pulsar Plus. So I think that one is a waste of money.

Or, save yourself some money by re-assessing how much power you really need for EV charging. I.E. don't go thinking you have to pay a fortune to charge at 40/50A. You totally don't.

Observations

I have 100 A service in my home; installing even a 40 A circuit for a 32 A level 2 charging station would put me razor-close to the safety limits of the service (as determined by a licensed electrician)

You don't need to take the electrician's word for it, you can compute it yourself by googling up NEC 220.82 and working through it carefully. I recommend reading the whole thing before starting, and working sort of "backwards", since a lot of specific things are counted individually and are excluded from the "catch-alls" listed above them. For instance there's a 3 VA per square foot "catch-all" that covers lighting, fans and virtually every plug-in appliance not fastened in place including window A/Cs. The 1500W allocations for laundry room and kitchen general-use receptacle circuits cover the clothes washer, gas dryer, refrigerator and all countertop appliances.

I am content to let the electrician judge (and the permitting agency, if necessary) judge whether these things work in terms of protecting the wiring of the house.

It's not their purview to judge them, it's UL's. Underwriter's Laboratories writes the White Book and other standards to which all approved equipment is judged. UL, CSA or ETL certify particular pieces of equipment to comply, and approve the installation instructions as complying with standards and NEC. The UL mark settles the question as to whether the item is legitimate, per NEC 110.2. Provided it is installed according to labeling and instructions (requried by NEC 110.3).