Ask the Expert: Is low mileage a bad idea in a Fiat 500 Hybrid?

Fiat 500 mild hybrid
Fiat 500 mild hybrid

Dear Alex

We are looking at replacing my wife’s much loved Fiat 500. It has a straightforward petrol engine but the new versions are hybrids. She drives about 3,000 miles a year, mostly local journeys of 10 miles or less. You recently warned that a manufacturer (not Fiat) advised that their hybrid cars should be run continuously for at least an hour a week to charge the starter battery. Clearly this would not suit my wife’s needs and I am concerned that the battery will flatten and we’ll be unable to start the car. Am I right?


Dear HC

You’re correct that some hybrid cars suffer when driven rarely, or exclusively on really low-mileage trips, because there isn’t enough time for the 12-volt auxiliary battery (as opposed to the larger battery that forms part of the hybrid powertrain) to charge properly.

That can lead to issues with starting, although these are solvable with the use of a trickle charger, either powered by the mains or by solar cells.

However, these problems won’t apply with the Fiat system, because it’s a different type of hybrid. The 500 is what’s known as a mild hybrid, which means it has a very small additional battery that’s charged by the starter motor, which can act as a generator (a bit like a dynamo) when the engine is not under power.

This provides a small additional shoulder to the wheel for harder acceleration, but it can’t drive the car by itself. The 12-volt starter battery, meanwhile, is charged by an alternator in a conventional way.

Full hybrids, like the ones you’re thinking of here, have a larger drive battery that can power the wheels, as well as offering a boost to the petrol engine.

The downside is that these cars also have a relatively small 12-volt battery, which drains quickly and can take a little more time to charge via the DC-to-DC converter, hence the issues mentioned above.

In other words, as with any other petrol car, a mild hybrid shouldn’t have an issue with low-mileage use unless that mileage is very low indeed. Or to put it another way – if your wife has been fine with her petrol 500 thus far, she shouldn’t have an issue with a mild hybrid example.

For new and used buying guides, tips and expert advice, visit our Advice section, or sign up to our newsletter here

To talk all things motoring with the Telegraph Cars team join the Telegraph Motoring Club Facebook group here

A-Z Car Finder