Very are very nice and usb recharable. Hard to say how often you have to do it, but I have similar unit under my sink and I do it every few weeks with a battery pack.
- 3-Pack of 4 Led Rechargeable Motion Sensor / Light $18
- 3-Pack of 14 led Led Rechargeable Motion Sensor / Light $26.50
please see specs on product page for the details.
+ free shippng