Best way to keep chassis battery charged over winter?

I use the Amp-L-Charge for two reasons.
1. I plug in the shore power and my three-stage converter charges house and chases battery all winter long with a maintenance charge.
2. When on the road and I use shore power, the chases battery stays charged no mater how long I am parked, and I can use the dash radio for as long as I want and the power is supplied by the Amp-L-Charge while still charging the chases battery. Works great.