Another vote for CTEK. I’ve had one running nonstop for 4 yrs and like Flinestone mentioned, I would rotate around. Added this one below, I have the older 4.3 MUS version…both have been great. You do not need to higher amp model if you are doing storage charging/maintaining. You have the two old style chargers to handle that, the 4.3amp of this model is plenty for storage needs. I even bought a .8amp model to maintain the generator battery.
https://www.amazon.com/gp/product/B00CD44RQO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
If you need to run long distances you can buy this adapter to use with the following SAE cable. I had a previous charger that used SAE…since it lives outside and further from plugs I use the 25ft extension with the adapter to leave my CTEK in the garage. You will need a SAE to battery connector which are also chea, again I only use for long runs. Any cars in a garage I install the CTEK battery connector provided with the charger.
https://www.amazon.com/gp/product/B07Z7T494M/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B002X6DQUA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1/
CTopher