Battery fun...

I know exactly what you mean about the chargers, and the absolute best one I ever had was a new electronic charger/converter I bought for my motorhome when I had it.

Here it is, and yes it's obviously not quite just a charger but as a "smart" charger goes it was awesome.
Inteli-Power 9200 80amp Converter/Charger-pplmotorhomes.com