The Lighthouses come without batteries. Selbige keep even a few weeks.
Tip: I have been in good AA Sanyo Akus invested and respective sleeves on thumbnail to view baby C batteries (!).
The normal AA Akus you can load in a normal charger. The Sanyo Eneloops are also so good that they are made to last and get no memory effect. Buy 4 pieces and 2 sleeves per Lighthouse, then you can switch quickly if necessary and recharge the batteries in tranquility. 1x costs, but ultimately save you money and stress vs. large C-Akus or normal batteries.
If it flashes, you still have 7-10 days for the exchange to said Akus.
Positioning the Lighthouses:
You have to juggle a bit with the placement of his power steering systems when the works are good all very practicable. An open house or a huge space should be divided into zones, which improves cleaning performance significantly. Roomba should be in the room in which it is to be cleaned most thoroughly, for me this is the living room. After all, not every day he finds all Lighthouses and really departs every room. The zones must be consecutively. So you can not declare the corridor as a zone and vesehen the individual doors in the adjoining room with Lighthouses, Roomba would otherwise only one of the following rooms starting and all other ignored. In the case, for example, should be in the middle of the corridor zoning. Do not worry, he will usually already in the next room.
Asking the Lighthouses in the doorframe, as iRobot it recommends, I think impractical.
They bother me because when walking - and too often I move it accidentally with your foot.
I put them on immediately before or after the doors. I think they are perfectly placeable on wall projections. Because then Roomba can start and move not laterally during room cleaning. Otherwise, they should be close to the wall or next to an object / furniture, then Roomba will not start. Every now and then I Nutty Little Bit, because the zone in which shuts off the Lighthouse is not cleaned like the rest of the house, run over only once.