On 7 Jan 2007 15:17:48 -0800, wrote:

Is anyone familiar with these battery operated sump pumps?
What do they use for batteries? What voltage? Are the bateries always being
charged when the power is on, or must they be connected to a charger manually?
Can more than one battery be connected in parallel so they pump longer? Can
they be run off a car battery in an emergency?

Check out http://www.basemen****chdog.com/

You can download the user manuals and get all the info you need.

As others have pointed out, water driven backups are attractive if you
have reliable city water (I have a well).

I have the largest Basement Watchdog system installed and it has saved
my basement several times already. When the battery is new, it will
run the pump for 6-7 hours continuously, much longer if the pump
cycles on and off. It uses a deep cycle marine type battery, 12
volts. You can connect two in parallel for longer run time. You can
run off a car battery (or even a car; with long leads) in an
emergency.

I have a generator for long outages, but if I'm not home, the battery
unit will keep the basement dry until I can get home and fire up the
generator. An automatic starting backup set is on the wish list,
but...

I think the concern over limited battery life is overblown. A battery
is $100. if you just replace it every four years it's $25 / year for
reliable backup.

The control unit tests the pump every day, and even monitors the water
level of the battery.

HTH,

Paul