I have been using Ctek chargers for years on various cars and motorcycles.
Now I have 2 90A batteries in the car, which stays connected to power for 6 months every year, and they are maintained flawlessly by a Ctek 0.5 charger.
Now I have upgraded to the CTEK MXS 10 for added safety and security.
It has an ambient temperature sensor to adjust the charging and a cable that you can permanently connect to the battery for charging whenever you want.
It supports AGM and EFB batteries.
It can also power the car even if you remove the battery for any reason or when you replace it, so you don't lose any settings you have made in the car that require power to stay in memory.
I discovered them several years ago when I saw that the exhibition cars at the Mercedes dealership in Kifissias had them on Ctek chargers.
I searched for them, read reviews, tried them, and yes, they are the top in the market.

I have it for almost two years and it is the best. Definitely expensive, but it will save you if the car is idle for a long time. Also, when I had regular batteries with liquid, even when they were dead and needed replacement, I revived them twice and they lasted me another 2 years. Now I have AGM batteries and it supports them without any problem. It even has an ambient temperature sensor to adjust the charging, and it also has a plug that you connect permanently to the battery, so whenever you need to charge, you just open the hood and plug in the device. Finally, it is generally good to avoid the negative pole of the battery and connect the machine's clamp somewhere on the chassis and the positive pole normally to the battery.