Ford's Hybrid and Electric Vehicle Unique Component coverage runs eight years or 100,000 miles, whichever comes first, and it reaches well beyond the battery pack itself. Ford lists the high-voltage battery and its connector, the battery energy control module, the on-board charger, the inverter system controller, the DC/DC converter and the hybrid transmission or electric drive motor among the covered components.

If a covered component needs replacing, Ford may use a new, factory remanufactured or factory refurbished part at its discretion, and states that a refurbished battery will be matched to your vehicle's age and mileage. Note that the ordinary 12-volt battery is a separate matter, covered for three years or 36,000 miles.

• Eight years or 100,000 miles, whichever comes first
• Covers the high-voltage battery and its control module
• Also covers the inverter, converter and drive motor
• Replacements may be new, remanufactured or refurbished
• The 12-volt battery is separate: three years or 36,000 miles

Ford is direct about aging: a high-voltage battery gradually loses capacity with time and use, the same as any battery, and Ford treats that as normal wear rather than a defect. Capacity loss from ordinary aging is not covered by the New Vehicle Limited Warranty. Ford also notes the battery is not covered if it is damaged by improper vehicle storage, so the storage procedures in the Owner's Manual matter if the vehicle will sit.

Emissions coverage is a separate system, and it works differently depending on where the vehicle is registered and how it was certified. Ford applies California emissions coverage when a vehicle is registered in a state enforcing those rules and is certified for sale in California, which is shown on the emission control label under the hood. Because the terms and the state list can change, the label and your Warranty Guide are the authorities, not a rule of thumb.

• Gradual capacity loss is normal wear, not a warranty defect
• Improper storage can void high-voltage battery coverage
• California emissions coverage is a separate regime
• Eligibility depends on registration state and certification
• Check the underhood emission control label

There is no scheduled maintenance item for the high-voltage battery the way there is for oil, but the surrounding systems still need attention, and the hybrid's cooling and software play a real part in how the pack ages. Keeping up with the maintenance schedule and letting the dealer apply updates is the practical answer.

Two more habits help. Follow the storage guidance in the Owner's Manual if the vehicle will be parked for a long stretch, and treat the hybrid's regular service like any other Ford's, since the gasoline engine still needs its oil changed on the manual's schedule. Ford publishes no lifespan figure for the pack, so be skeptical of any number quoted as Ford's.

• No scheduled service interval for the battery itself
• Keep to the vehicle's normal maintenance schedule
• Follow Owner's Manual storage procedures
• The gas engine still needs its regular oil changes
• Ford publishes no expected battery lifespan