I don't want to come across as a know it all, but my position as a Army Maintenance Officer give me unique perspective. I have been part of the fielding of hundreds of equipment platforms, and all with their own issues. When there are problems my team is called. As a educated guess, I find 95% of the problems are operators or untrained mechanics fault. My favorite is wire cutting and splicing. Most people do this task wrong when adding lights, radios, accessories, etc. Most people cut the wires, twist them together, and apply black tape. This is what I call a temporary road side fix. The little blue wire splicers sold in auto parts stores are no better. These types of splice work well for a few days, but then corrosion sets in because they are not sealed or solid. The best way to make a permanent splice is to slide on shrink wrap, twist and solder the wires together, and then shrink the wrap. This is a permanent fix.
The biggest problem I see is people letting equipment set. Even if you are not using the equipment, it needs to be started and ran for 30+ mins every two weeks at a minimum. This action alone will save many batteries, time, and money. Don't be surprised when your equipment will not start on a cold day, when it has not been touched in a month.
Also, don't buy a battery just be cause it fits the space. Cranking amps, and Cold Cranking amps matter. Especially in cold weather. Diesel engines fire using high compression which takes a lot more juice to turn over. A weak battery causes problems in glow plug functionality also. Using cheap batteries cost more in the long run.
Again, I am not saying "there are not legitimate non-starting issues", but most are caused by operators/mechanics. I see starting issues from $1000 generators to $800,000 fighting machines. I am not looking for a fight, but if you breeze through the other forums, the non-start issues are evenly posted among all makes.:thumbsup: