why does it need a 9v battery if it is plugged into an outlet
635066
It will work anywhere even without being plugged in. Good also during power outages. Plugging in will save battery.
635067
For backup in case of an electricity blackout. But this product is awfull. Do not buy it. Instead of using the battery for emergency purposes it drains it in a couple of days turning the alarm on.
635068
The theory is that it is a power outage backup. The problem is that it goes dead even though it is supposedly not being used. Without the battery you get warnings.
635069
For Backup in case power is lost. But, I wouldn't buy it--it doesn't work well
2271927
The unit plugs into a regular wall socket.It takes a 9 volt battery for portable use.
1462473
You would use the battery power if there were no electrical outlets such as in the backyard. It comes with a charger so you just plug it in the outlet.
1174921
this is basically a plug. u plug it into an outlet, u cant just put new batteries in it
1059755
No, it uses two AAA batteries and this is one of the main reasons I bought it. I use rechargeable AA and AAA cells and avoid 9v if possible.
665212
9 volt battery - one of it's problems - it does not allow for being turned "off or on". It's just on once you start using it meaning that there is a continual electrical current going which makes it very hard to do as you are electrocuting yourself as you are trying to insert the needle into the hair follicle.
268407
I do not have a 9V battery in mine and I unplugged it for five minutes just to test this. It did not seem to lose its tare weight or configuration information.
1907955
It replaces your 9 volt battery with a cord you plug into your wall outlet.
1933112
It needs an adapter only if you don't want to buy the required 9 volt battery. Personally, if you remember to turn it off after each use, the battery will last over a year. I've had mine for almost 2 years and still haven't changed the battery. (My wife will let me know the second we need one!)
2185659
does not need to plug into an electrical outlet. it is a ten year sealed battery. so mount it where you want, and replace it ten years from now!
534712
It uses 3 AAA batteries not 9V. AAA's are 1.5v per battery. It uses photo-electric technology.
1056963
The switch runs off of battery, the outlet is powered by the outlet you plug it into
2219483
Hey Mr. Robert L.,It takes a nine volt battery. Mine did not come with the battery.
1986053
Mine just came with battery. But looking on the back there is a place for a DC:9V adapter. So I guess you could plug it in if you had that type of power adapter.
2152755
Not sure what you mean... plugged in to a power outlet? Maybe if you have the same output voltage (7.2V) as the battery.
1349384
The power source are suggested to plug in all time as the battery can last 4 hours on itself. It is in a clock shape, so people would not be suspicious with the power plugged in.
176724
SORRY.......it requires 2 9V. Everyone helped you with that one, and I made the mistake.