“Heavy-up” is trade slang for increasing the capacity of the electrical service. On a residential EV quote it usually means replacing or upgrading the panel, often the meter socket, and the service-entrance conductors so the house can be rated at a higher amperage — most often 100 amps to 200 amps. It is the job described on the 200-amp cost and “what is included” pages, not a special kind of charger. If the load calculation or the physical panel cannot support the EV circuit, the quote may split into “EVSE install” and “heavy-up,” and the second line is often the larger one.
Related phrases you may see on the same sheet: service upgrade, panel upgrade, 200-amp service, meter-base change, or “utility coordination.” A listed energy management system is the usual alternative the electrician may offer instead of a heavy-up when only the charger does not fit. A “200-amp panel” that leaves a 100-amp meter in place is not a completed heavy-up.
Ask for the heavy-up scope in writing, compare it with the included-in-the-upgrade checklist, and use the calculator so you understand why that line item appeared.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.