Ask Honest John

Most recently answered batteries questions
I have recently bought a 2019 Volvo XC60 D4 with a low mileage - 20,000 miles approx. The auto start did not work at all for the first week and now it only works after a fairly long motorway drive - then...
My 2016 Honda Jazz has 50,000 miles on the clock. Should I replace the battery?
I have a Ford Puma 1.0 MHEV but have fault with 12 volt battery losing charge. It will run fine for two or three weeks but then will require jump start two or three times .Previously the car had a total...
To beat the dreaded short journey issue with stop start batteries is it worth putting a bigger capacity battery on my Fabia or will it upset the charging system?
I have a 2017 BMW 440i still running on its original 12-volt battery. Although there are no obvious signs of failure, the alarm went off yesterday for no apparent reason and I’ve been told a weak battery...
I have a 2024 Nissan Qashqai e-Power which I left at the airport for 2 weeks. When we got back my car battery was flat. Is this common on self charging hybrid cars or just Nissan? And why put such a small...
My 2000 VW Beetle has a flat battery. Our mechanic says there's nothing wrong with the alternator or battery. Can you help?
As I will only be doing short infrequent journeys should I buy a solar battery trickle charger. If so which is best and easiest to connect please. Possibly not connecting to the battery terminals. Will...
During the summer months, both my wife's car (2025 - Suzuki Swift Hybrid) and my vehicle (2021 - Toyota RAV4 Hybrid) will be unused for approximately 3+ weeks, due to an impending holiday. Both vehicles...
When going away for a number of months I have left my previous ICE cars on a battery conditioner in the garage to preserve the 12 volt battery. I now own an EV and have read that this would not be possible...