Anybody who claims they are an "Expert" I am very wary of, I never claim to be an expert, and believe one should always be ready to learn something new. I probably started engineering at the age of say 13-14, My mother and I ran two boarding houses, I had to do basic house maintenance , fix lawn mowers, beds etc. At 17 I was taken on as an apprentice aircraft engineer, over time I finished my apprenticeship, then went on to get my licences, which allowed me to certify all aircraft on both engines (including turbo and supercharged) and airframes, to fly, i.e. issue a certificate of airworthiness on aircraft 7500kg or less. I also got types certificates on the PT6 turbo prop engines as well as some radial piston engines.
From there I moved to the wine industry (because I had hearing problems) where I spent a further 20 years doing maintenance and design work in one of our large wineries. When I moved West, I got a job servicing fitness equipment on the gyms about Perth.
At 66 years of age, I now work as motor mechanic at one of the local councils. I would however not class my self as an expert, just willing to share my knowledge, and or learn from others.
I also undertake to solve mechanical problems and in doing that, I did a fair bit of research on batteries.

The other point is that those who can post topics that bring on rousing debate, I think need to be applauded, with out these, this forum and many others would be dead. So good on you Adreamer.