There's been several posts about battery trickle-charge/maintainers in the "tool" thread (NFC section).
The experiences of many people seem to vary significantly; some have a "fill in the blank" brand unit that has lasted 100 years while others had it last a day, some are highly dedicated to one particular model while others have had zero luck with every option on the market.
Honestly I haven't figured out the trick to success with battery maintainers. Price doesn't seem to be any indicator of success, neither does brand or model (however as stated previously, HF items can be very 'hit or mis' in quality). I've owned numerous brands (including all of the ones mentioned in this thread plus several others) and none of them have been extremely reliable. A couple did last several years...or so I thought. Turns out they had destroyed the battery but it wasn't apparent - the indicator lights said everything was good when in fact things were quite the opposite. [I should note that I do keep the fluid levels properly filled, terminals clean, battery/maintainer located in an appropriate area, etc.]
I have noticed a couple of interesting differences between various units. Most have no ventilation. They are a sealed box (although many have what appear to be vents, but they are fake). And the internal components get pretty hot even when it is in a 'idle' mode. I understand they want to make them water resistant for outdoor use, but the lack of air circulation might be a major factor to their short life. Another thing I've noticed is how robust (or not) some might be. As you might guess the tiny, light weight, skimpy units seem to be less durable than some of the more substantial ones. Although after doing an autopsy to some dead units I've found that what's inside doesn't necessarily reflect the size or mass of what's outside. I'm sure there are major differences in the internal component quality among various brands/models, but there's really no way to determine that when buying one. As I said, price does not reflect quality anymore.
Many decades ago when there wasn't much of a market for these things, and I was a poor student that could not afford a 'real' one, I tried something simple. I took a leftover "wall wart" power supply that had less than 1 amp output at 12 volts and cut off the connector plug on the end. Then I wired the leads directly to a motorcycle battery (typical flooded wet cell type) and I put the wall wart into a generic timer set to be "on" less than an hour a day. That battery lasted almost 10 years. Go figure. But I do not recommend doing this.