I have been using Battery Tenders for 32 years, and I have never had an issue with any of them. I am using 3 at the present time. I have found that i get a lot longer battery life with them. The last battery i had to replace was 11 years old.
Same here. Get minimum of 7 years on batteries of vehicles that don't get used a lot (my first set of diesel
truck batteries lasted 10 years and I only replaced them as I started to worry someday, they would go).
I have about 12 of those 1.5 amp trickle chargers (cars, trucks, lawn tractor, bobcat, trailers, etc...).
They stop working here and there, but no other issue.