The HF trickle charger I used many years ago failed and ruined the battery. Used "Battery Tenders" since, 4 or 5 of them on different vehicles without any issues.
Been using HF float chargers for over 10y, I have not has a single prob and everything have been working flawlessly. I checked the bat I use for my dump trailer which spends 99% of it's time in my shop on the HF, it was drawing 5ma at full charge.
Never forget, there is no such thing as trade secrets in China, the mfr of the HF supplier's factory is across the street (literally, unless it is the same factory) from the premium brands, and management crosses the street every day.
Why do you think they do not allow foreigners to use cameras in SIP?!??!?! I have been there.
The Suzhou Industrial Park spans an area of 278 square kilometres (107 sq mi), and has a population of 807,800 permanent residents, per a 2019 publication released by the industrial park.