My two units arrived quickly and were placed into service straightaway.
So far so good . . . appear to be working as advertised.
Deal remains available as I write this. No regrets. I can use these things but was unwilling to pay the higher prices elsewhere.
Sad to report there is a HUGE problem with these maintainers which I’ve only just confirmed:
These things are ginormous generators of EMI, sometimes also called RFI. That aspect does not interfere with their ability to maintain a battery. In fact, if you never listen to AM radio this is not even an issue for you.
I operate four Sangean PR-D5 radios in various rooms around my home. The PR-D5 model is noteworthy for its ability to pull in distant radio stations and sadly, as well, EMI from battery chargers like those in the OP.
I’m guessing now these maintainers are completely unsuppressed where EMI is concerned. Maybe that contributes to the low price.