A tender/trickle charger is good for lead acid batteries but you have to keep it on all the time. As mentioned by Walt501 above, an Odyssey (or other good AGM) battery will not self-discharge so much. Also note that AGM batteries are charged with a 40A charger not a <2A charger. When buying a charger, look carefully at the duty cycle because there are a lot of high claims out there "40A" but the fine print tells you it's intermittent and might be as low as 10% duty cycle. The continuous rating might instead be 4A, but the charger will be labeled "200A Start" and "40A Boost" -- it's all smoke. If you study it carefully, you'll see a lot of the high-amp starting claims are actually the current at 3.6V. It's not surprising the current spikes to 100 or 200A because the voltage sags so low when you start cranking -- what a pathetic joke.
Basically, if you want something better than a trickle charger, it's going to take a big-ass transformer and they're usually mounted in a rolling cart and cost several hundred to a thousand dollars or more. Just think what it takes to deliver enough current for welding. Don't try to weld with a little lunchbox size piece of junk, and don't try to charge a big battery with a little wall-wart.
FWIW, like Walt, I've got Odyssey batteries -- my first one was a Sears DieHard Platinum (rebranded Odyssey). I still have it in my big pickup after 11 years. I have about a half dozen of them in vehicles and they're all about 5 to 10 years old and they all work. The ones that don't get used (because they're backup batteries on the 4x4 etc.), I put on the battery cart once a year. I just went down to Napa and bought whatever the biggest battery cart they had was. The AGM prefer a fast charge.
My wife's car is the only one with a lead-acid battery because it's a 2019 and it came from the manufacturer that way. Three months of quarantine and it was dead. Eventually, I'll swap it out because it won't hold a charge, usually after 4 years. I'll put another Odyssey in it. They cost twice as much but last at least 3 times longer and never need a trickle.
