All Robotic Mowers Are Not the Same

All of the mowers provide a beautiful cut. They are all mulching mowers in that the cut blades of grass are small enough to fall between the grass blades and quickly begin to decompose. This eliminates raking or clippings disposal. Each brand has their own way of doing this.

LawnBott	Robomow	BigMow
Lawnbott uses a thin, low-mass, double edged blade. This is perfect for conserving energy while cleanly trimming the tips of the grass. If an object is encountered, it will flex a bit.	Robomower uses one or three (depending on model) hardened blades recessed within specially designed mulching chambers This can take on fairly long grass without a bit of visible clippings being left behind.	BigMow uses thin blades similar to those you might find in a utility knife to constantly trim. Only a small sharp area is exposed. If the blade contacts something, it swings back inside the mounting disc and returns on the next rotation.

All of the mowers keep safety as their first priority. The designs above all but totally eliminate the possibility of objects being thrown from beneath the mowers. Projectiles like rocks, sticks and balls launched by traditional mowers result in a large number of serious injuries each year. As of the date of this page being created, there are no recorded emergency room visits at all related to robotic lawn mowers.

All of the mowers use bump sensors to detect objects in their path. Robomow RL series and BigMow use rubber bumpers with internal contacts. The Robomow RM series and Lawnbott models use switches activated by the movement of the shell. All of them are fairly sensitive. An additional feature that all of the mowers share is a tilt sensor that stops the blades or shuts off the unit altogether.

The Lawnbott LB3500 and BigMow provide an additional level of safety. BigMow incorporates a set of sonar "eyes" that slow the mower to a crawl before making contact. The "tap" is surprising light considering the size of the mower. The LB3500 Lawnbot has a touch sensitive lift handle that turns off the blade if touched with your hand.

All of the mowers use standard household current to charge their batteries. Although a solar powered mower was available for a time, it proved to be less than efficient. The batteries themselves are Lead Acid (like your car), Lithium Ion (like your cell phone) or Nickel Cadmium (like rechargeable tools). Each has their advantages and disadvantages but were selected to match the operational characteristics of the particular mower.

Lead Acid has a reasonable service life, and it the least expensive. It is also the heaviest. This can be a good thing in that the weight helps in providing traction. The Robomow models all use these as well as the Lawnbott LB2100 Professional. They can tend to lose some capacity each year so make sure that you don't go above the recommended lawn sizes. It may cover it the first year....

Lithium Ion has a good service life and does not tend to get weaker with age like lead acid batteries do but are more expensive. They are amazingly light. So light, in fact, they almost feel "empty" when you hold one. Their weight to available power ratio make them very efficient for robotic mowing because it takes power to haul the batteries around the yard. The Lawnbott LB3200 and LB3500 both utilize these and have available space for additional cells to boost capacity.

NiCad batteries are commonly found in rechargeable tools of many kinds. They will build up a "memory" if not discharged fully before each recharge. They "think" that they only have enough power as the last few times used. The BigMow uses this type of battery. Since the BigMow discharges its batteries before returning to the dock, "memory" will not come into play and they work very well.

Just a final word on Solar Power.
We have investigated this and found it to be cost prohibitive for the average person to power their robot via the sun. However, it you have a special application or the funds to spare, we would be happy to assist you.