Down here we don't get snow and stuff like you guys get up there. My battery has never discharged to the point where the fence didn't have a charge.
The day I bought mine I took it home unwrapped it and left it sitting on the kitchen table a couple days. The oldest boy (20+yo) just had to play with it. He managed to get the switch on and make contact to -- and +. Next thing I hear is him yelping and see him jumping around the kitchen. Point is it will charge inside sitting under fluorescent lights. So during the daylight hours when you are home. If its cloudy charge it inside, at dark hang it back on the fence when you need more protection. Not perfect but it may get you through the next few days.
That being said---- I have two fence chargers. A conventional 110vac and a solar charged unit. I keep the ac charger on my chicken enclosure, and the solar stays out in the field to provide sectional containment for the horse pastures.
The horses will not try a dead wire, they see the wire, they avoid it like a plague. Prior to comming to my place I think they were "learned" about hot wire.
