What battery charger for winter storage?

or simply remove the battery and store it at room temp shouldn't drain or use electricity the whole winter, unless you have a climate controlled garage like mine they store fine here in Colorado

Actually you should charge it fully or in other words determine that it is fully charged and store it in a COOL place.

The warmer the battery, just like any chemical reaction, the faster it will self discharge.

Some people keep flashlight / other batteries in the freezer. I don't do that but I DO keep them in the 'fridge.