I have a sump pump in a well beneath my floor. Works great and keeps the basement dry. However I fear that we may get water at the same time we have a power outage. So I've been looking at battery back-up units. Most kits that I've found in stores around here have a 12 volt pump that attaches to the outlet of the existing electric pump. It kicks in if the water rises in the well above the cut-in level of the AC float. This DC pump is powered by a deep-cycle battery (not included) that is kept charged by trickle charger (included).
The kits include the 12 volt pump, a charger, a plastic box to hold the battery, and a few fittings. The cost here in Canada is between $250 and $380 (I think the more expensive ones have a fancier charging unit and perhaps the pump delivers more gallons per minute. Isn't that a bit expensive for what you get? Especially as there is no battery included?
I'm wondering if I could purchase the pump and a trickle charger separately for considerably less. Someone suggested a marine bilge pump. Do these pump the volume of the sump pumps - about 20-25 gpm? Is the trickle charger sold in the kits any different/better than a cheap trickle charger sold at any hardware/automotive store? The ones in the kit don't look to be all that elaborate. Also, are all deep-cycle batteries equal? If they are left on charge continually, will they hold a full charge for a long time (years)? How often would they have to be replaced?
Any suggestions or assistance would be appreciated.