Do plug-in hybrids self-charge while driving?

Does a plug-in hybrid have any self-charging capability?

Asked on 10 May 2021 by Chris Keene

Answered by Dan Powell
Some plug-in hybrid electric vehicles (PHEVs) can self-charge. They do this by overworking working the engine to generate the additional power to recharge the battery but this is a very inefficient way to drive a PHEV (as the mpg will plummet as the engine works hard to generate the extra power).

Generally, a PHEV will recuperate lost energy under braking and use this to top up the battery (adding one or two miles.) The plug-in battery (when fully charged) will provide the car with an electric range of 20-30 miles, which will lower the overall fuel economy on a long journey (with the battery assisting the engine) or allowing the driver to power the car from pure electricity (perfect for driving in a town or city).

The hybrid system will recharge itself in a similar manner to a mild-hybrid car (recovering energy under braking); however, this will only add two or three miles to the battery and will not fully recharge the entire plug-in system. PHEVs are not designed to be driven without a fully charged battery. The additional weight of the battery will sap fuel economy to around 30-40mpg.

If you want to know more about life with a PHEV, read our long term test of the Volvo XC40 Plug-in Hybrid here:
Similar questions
I'm looking to buy a secondhand family car. I will do short commutes to work (7miles), schools trips and occasional long journeys. It will need to be a load-lugger as we have a large dog, two kids and...
I tow a small trailer, which I use to transport horse muck, firewood, pallets etc with my 2011 Mini Countryman diesel. I was looking to replace it with a 2020 Mini Countryman SE PHEV but found out you...
In the next few months, I will buy a new SUV. Is it better to buy a petrol, plug-in hybrid or all-electric nowadays?
Related models
Chunky upmarket and bold styling, excellent all-rounder, EV and plug-in hybrid versions.

Value my car