Hello Doctor. How are you… not too cold or wet I hope? 

When you have a moment, could you perhaps please advise me about my car battery. In the Fiat DoblÚ, I do a run every four to five weeks of approx 75 kilometres to see my sister, and then back the next day. Other than that, it’s just one local trip per month of around eight kilometres, with two to three stops. I am trying to be good and walk the rest of the time.

Presuming that the alternator is working properly, and the battery is in good order (it is only about two years old), am I doing enough mileage to keep it charged up, or should I be using a trickle charger regularly? David had a solar panel that he bought as a charger, but all the websites seem to suggest that a charge controller is necessary as well to avoid cooking the battery. Any advice would be much appreciated, as I am having to learn about cars again, after having someone else deal with it for the last fifty years. Many thanks, and best wishes, 

Carole Perry, France

Carole, your DoblÚ’s lifestyle sounds not too dissimilar from my wife’s 2003 (petrol!) BMW, which we suspect (we’ve had it for 10 years) is still on its original battery, and handles covering little more than 1,500 miles a year, composed of a few local runs and a 50-mile return trip probably every three weeks on average, with no problems.

Alternators and batteries are that much better than they were a decade or two ago, that they can handle such patterns of relatively light usage. As long as the engine turns over enthusiastically when you turn the key, I think you can be sure that things are alright, and they should stay that way for quite a few years yet, if it’s a good quality battery. My ride-on mower’s battery (which was new about five years ago) goes right through from probably late October to late February with no usage whatsoever, and when I put the charger on, usually in December, to make sure that it’s keeping alright, the charger cuts out within minutes.

I think you may be correct about the solar panel, and I would leave it alone. I don’t know what your servicing routine is usually like with the DoblÚ, but at that annual mileage that’s probably under 2,000 miles, an annual service and oil and filter change is a bit over the top. We concluded this with our BMW, and now my little independent garage uses long life oil and leaves it for two years between services, although I would soon take it in to him if there were any funny noises, and it still gets checked over every year for its MOT test. We spend more now (£260) on the vehicle excise duty (the old road tax) than we do on fuel or routine servicing!

Kindest regards,

Doc Diesel