Charging

Understanding the levels, the connectors, and which box does the actual AC-to-DC conversion tells you immediately which failures are possible and which are not.

Charging Levels: 120V, 240V, and DC Fast

Level 1 charging uses a standard 120-volt household outlet. It is the slowest option, adding roughly 2 to 5 miles of range per hour — fine for a PHEV or a short commute, painful for a big BEV pack. Level 2 uses a dedicated 240-volt circuit and adds roughly 10 to 40 miles of range per hour; it is the standard home and workplace solution. Level 3 is DC fast charging, capable of adding 100 or more miles in about 15 minutes at public stations.

The architectural difference matters more than the speed numbers. Level 1 and 2 deliver AC to the vehicle, and the vehicle's onboard charger (OBC) converts that AC to DC to charge the pack — so AC charging speed is capped by the OBC's rating. DC fast charging moves the AC-to-DC conversion into the station itself: the charger feeds DC directly into the battery, bypassing the onboard charger entirely. That is what allows the much higher power levels.

This split is a gift for diagnosis. An onboard charger fault kills Level 1 and Level 2 charging but usually leaves DC fast charging working fine, because DC charging never touches the OBC. A customer who can fast-charge on the road but cannot charge at home is describing an OBC problem — confirm that pattern before replacing anything.

EVSE, Connectors, and Standards

The box on the wall or the pedestal in the parking lot is the EVSE — Electric Vehicle Supply Equipment. Despite being called a 'charger' colloquially, for AC charging the EVSE is not the charger at all; the real charger is onboard the vehicle. The EVSE's job is to regulate power delivery, provide safety interlocks, and communicate with the vehicle over a pilot signal so both sides agree on available current before any power flows.

On the DC fast-charging side, two connector standards matter in North America: CCS (Combined Charging System), the common standard across the US and Europe, and NACS, the connector Tesla developed, which is now being adopted industry-wide — Ford, GM, Rivian, and most other OEMs have committed to it. Adapters bridge between NACS and CCS during the transition. CHAdeMO is the older Japanese standard, now fading, found mainly on earlier Leafs.

Charging Habits and Battery Life

How a customer charges shapes how the pack ages. Repeatedly DC fast charging to 100% and running the pack down to 0% accelerates degradation compared to living in partial cycles around 20-80%. The pack is happiest in the middle of its charge window; the extremes stress the cell chemistry, and the heat generated by fast charging compounds the aging. This is customer-education territory: daily fast charging to full is a habit, not a defect, but it will show up as capacity loss years earlier than gentle home charging.

Diagnosing Charging Complaints

When an EV suddenly stops accepting fast charging, resist the urge to condemn the pack. The three usual suspects are thermal management protecting the battery — fast charging is heavily throttled or refused when the pack is too hot or too cold — a fault at the charging port itself, or a communication error between the EVSE and the vehicle. Check pack temperature data and pull DTCs before anything else.

And always start with eyes on the charge port. Physical port damage — bent pins, a broken latch, moisture intrusion — causes charging faults, communication errors, and overheating during charging, and it takes thirty seconds to inspect. Plenty of packs have been misdiagnosed over a five-dollar latch. Inspect the port visually before diving into pack diagnostics.