Robot Lawn Mower Glossary

Robot Mower Technology

If you look at the specifications of a robot lawn mower, it can be confusing, if you are trying to compare across manufacturers, it can be bewildering.

Hopefully the below glossary will help you…Contact Us if there is something that we can add for clarification.

For Ambrogios, have a look at the Ambrogio specification comparison.

Categories:

Power

Manufacturers state the maximum lawn size for their robots but that is really just a starting point.

Maximum lawn size

This is the theoretical lawn size the robot mower can handle as is sometimes stated with  +/- x %.  It will normally allow for all the grass to be cut twice a week assuming it runs 7 days a week at the maximum defined schedule – see robot free time.

Measure your lawn to work out the size but then consider consider other factors which will impact this:

  • Travelling to/ from multiple areas will reduce the time available to mow and hence will reduce the area your mower can cover.
  • A long thin strip of grass will take longer to mow than a square one of the same area so this will reduce the area your mower can cover.

Battery

Most manufacturers will state the battery type (mostly lithium) and the capacity in Amp hours (Ah).  The bigger the capacity, the longer it will run…but also the longer it will take to charge and the heavier the mower will be.

Battery capacity degrades over time normally stated in x% degradation over a number of charging cycles – although few manufacturers state these figures.

Average working/ recharge Time

The amount of time that the mower can mow when it is fully charged and how long it takes to charge.

In theory, so long as the mower will cover your area, it doesn’t matter.  In practice, a shorter working time will mean that it needs to make more visits to the base to charge.  The more charging visits, the more time it spends getting to/ from the base and the less time cutting…and also the more charging cycles the battery goes through which  over the long term will reduce its capacity.

The recharge time varies according to the battery capacity and the power of the charger…the shorter the better.

Robot free time

This gives the best indication of the battery & working times.  It is a measure of how much time there will not be a robot on your lawn when working at the maximum area, most importantly, it should include the recharge time and hence is the total time that you schedule your mower to mow…even if it is charging.

Work out when you want to use the garden i.e. with no mower there and then see how the mowers schedule can fit in with this.  Remember that the mower can be scheduled to mow overnight (e.g. 9pm – 7am), mow in multiple periods (e.g. 7am – 11am & 6pm – 10pm) and can mow in different areas at different times – so if you want to use one area, you could send it to work in another.

Motor type

A lot of robot mowers now use brushless motors.  The advantages of brushless motors over brushed motors are:

  1. Higher efficiency and performance – i.e. will mow for longer on the same charge
  2. Lower susceptibility to wear – i.e. will last longer
  3. Reduced noise when working – a quieter machine
 
All Ambrogio mowers now have brushless motors.

Setup/ Control

Robot lawn mowers have become more sophisticated over the past few years and can be controlled via an App, smart assistant and include sensors which help with mowing.

Mower controls

Smaller robots tend to have a keypad and leds which allow simple control functions and feedback and then rely on an App for more functionality.

Larger robots tend to have a screen for further control – a touchscreen is usually easier.

App controls

If you are using an App then you may need to connect over bluetooth (i.e. within 10m from the mower) or if the mower has a mobile Sim them you can connect over the internet (so long as the mower has coverage).

Whilst you will normally be setting up the mower when you are in the garden (i.e. within bluetooth range), internet connectivity will allow you to receive feedback from the mower when you are away from home and let you have limited control over the mower. Internet connectivity combined with GPS is a security feature to track your mower wherever it is.

All Ambrogio models use the Ambrogio App, the Deluxe models are bluetooth only the rest have internet connectivity (The L400 Deluxe also has internet connectivity).

GPS

If your mower has GPS then it can be used for tracking the mower (security) and improving its cutting performance.

Ambrogio robot mowers use the GPS for:

1) Smart Cutting – which allows the mower to keep a map of where it has mowed so it can concentrate on areas it hasn’t mowed in the last 3 days.

2) Finding its way back to the base without using a wire

3) Setting a geofence – a circular area around your garden which it will alert you if it goes outside.

All Ambrogio Elite models have GPS as does the QUAD and the L400 Deluxe).

Rain sensor

Whilst a robot mower can cut in the rain, it can lead to a build up of grass on the cover.  We normally advise people to not cut when it rains unless they need to i.e. the grass is growing particularly fast or it just keeps raining!

All the Ambrogio models (apart from the L60) have a rain sensor which you can set in the App to either go back to the base or keep mowing when it senses rain.

Eco mode

There is no point in sending your mower out to cut the grass if it is not growing.

Eco mode senses when the blade is not cutting any grass and after a period will tell the mower to go back to base.  Sounds good? In theory it is good, in practice it is helpful if all your grass grows at the same rate. 

On Ambrogios, you can turn  this off if you have uneven grass growth otherwise it may find no grass to cut in one part of your lawn whilst there is longer grass in another part.

Smart assistant

With more homes have smart assistants (Alexia, Google etc.), more manufacturers have developed integrations to the smart assistant to allow you to send commands via them.

Ambrogios integrate with both Google Home and Alexia.

Cutting System

When you start digging further and comparing models from different manufacturers then another area to look at is the cutting systems.

Number of areas

Your garden may be physically divided up into different areas which the mower can move between (commonly back and front garden).  Alternatively, your garden may have a narrowing between different areas which would hinder the mower going between the areas during normal mowing.

In both these cases, we would set these up as different areas.  In order for the mower to navigate between the areas, it needs a passageway of at least 70cms width.

Our smaller mowers can cater for up to 4 areas, the larger up to 8 areas.

Cutting width/ height/ adjustment

The cutting width is the width the mower will cut in one pass i.e. the blade diameter.  The bigger the blade the more power it needs to spin the blade at the necessary speed to give a clean cut.

Cutting height is a measurement of the height from the bottom of the wheels to the bottom of the blade.  Remember that the wheels will have grass under them as it mows rather than be on the soil.

Most mowers have adjustable heights which are either at set heights i.e. 30, 40, 50 mm or totally adjustable between the upper and lower height.

Ambrogio models are totally adjustable apart from the L60 which has a spacer to adjust it from the higher to lower height.

On some models you adjust the height from the App (automatic) on others you adjust it manually moving the cutting head up/ down.

As a guide, 25mm would be a very close cut, most lawns are normally cut around 40-45mms.  Remember that the point of a robot mower is to maintain a consistent length of grass so start high and lower it until it gets to short (slight browning) and then raise it a bit.

Blade type

Mower blades come in many different configurations. Some manufacturers use individually replaceable razor blade type blades, others a more standard star blade.

+INFINITY SYSTEM

+Infinity Cutting System

The +INFINITYSYSTEM available on the Ambrogio range, allows you to run multiple mowers in the same area. Each mower maintains a map of the area to be mown and shares this with the other mowers on the lawn so that they don’t mow the same area.

This allows you to increase the area that can be mown (up to 20 acres) , decrease the amount of time taken, or both.

The mowers don’t even need to be the same model. So if you increase the size of your garden (maybe add a paddock to your garden), you can just add a new mower.  

Just look for the +InfinitySystem sign on the mowers (all mowers that mow 3500 m² and above).

+Infinity System
Play Video

Smart cutting

Traditionally, robot mowers move around the garden in a straight line. When they encounter the perimeter wire, they turn and start mowing at a random angle to the wire.  The randomness ensures that over time, the mower covers the lawn completely. The downside of this approach is that the mower will be mowing grass that it cut previously and hence this reduces its coverage. 

Smart cutting is where the robot mower uses additional technology to minimise the amount of lawn that it cuts more than once in a given period.

Ambrogio’s approach is to create a virtual map of your garden using its GPS and divides it up into squares – see the +INFINITY video above for more details. 

When the mower enters a square, it checks if the area has been fully mown recently (last 3 days), if it has, the robot continues to mow through the square, if it  hasn’t, it cuts the square in a spiral and then moves on.

The intelligent cutting improves coverage over the traditional random cutting pattern by about 30%.

Slope

Most manufacturers quote a figure for the slope a mower can handle but to understand what that means, you need to dig further as the slope depends on the conditions and where the mower is on the lawn.  Most manufacturers quote a percentage figure rather than a number of degrees as it is easier to measure. 

To find the percentage slope, you can use a spirit level app (use a plank of wood to rest your phone on) or work it out your self: percentage slope = increase in height / distance measured i.e. stand on your lawn if you are 1.75m tall, and when you look at your lawn straight ahead (i.e. horizontally) your eyes fix on a point on the lawn that is 5m ahead of you, the slope would be 100 x 1.75/5 = 35%  (multiply by 100 to give you the percentage)  – this is an approximation as your eyes are not at the top of your head and when you measure the distance ahead you’ll be measuring it on a slope not horizontally.

You do not need to be very accurate unless you find that your approximation is close to the maximum for a mower.  Some mowers allow you to add ‘spikes’ to the wheels which give it greater grip, these can be provided by the manufacturer or a third-party add-on.

Maximum Permissible slope

This is the maximum slope that the robot can manage away from the perimeter wire under good conditions – it should not be exceeded.  This figure may be reduced if the lawn is slippery, bumpy or has limited grass coverage.  Spikes can be used to improve the chance that this figure can be met. 

Maximum slope

This is the maximum slope that the robot can manage on away from the perimeter wire under ‘normal’ conditions. 

If you have a greater slope than this,  you may find that the mower starts to slip and it will normally treat it as an obstacle and turn away and later come at it from another angle.

Slope at perimeter wire

This is the maximum slope that the robot can manage on or very near (within 0.5m) the perimeter wire.

This is less than the max slope as the mower needs to slow down and turn at the perimeter wire and hence this is where it needs most grip .

If you have a greater slope than this at the wire,  you may find that the inertia of the mower may cause it to go outside the wire or slip when turning.

Security

Security relates to anti-theft controls as well as the security/ well-being of people/ animals who may be near the mower.

Whilst the theft of robot lawn mowers is rare you should ensure that they are covered under your insurance

Most of the Ambrogio range is trackable and its functions turned off by the manufacturer in the case of theft but that does not mean a thief will know this – we put a sticker on our mowers as an extra deterrent.

There are a number anti-theft measures but the most common are listed below.

Pin required

A pin may be required to turn on or turn off the mower.  This could be entered on the mower itself or on an App connected to the mower.  If the mower is already turned on, without the pin entered, the tracker will remain operational.

Tracking

This uses the mobile connectivity of the mower and its GPS so that you know where your mower is at any time.  The tracking can’t be turned off without a pin or removing the main modules from the mower which would be very costly to replace.

Geofence

The geofence is an invisible perimeter that is set around your garden.  When the mower goes outside of this perimeter, you are notified via the App.

A pin may be required to turn on or turn off the mower.  This could be entered on the mower itself or on an App connected to the mower.  If the mower is already turned on, without the pin entered, the tracker will remain operational.

Features

Weight

The heavier a mower is, the more likely it is to mark your lawn when the ground is soft but remember a robot mower still weighs considerably less than a conventional mower. 

Size

The smaller a robot is, the more manoeuvrable it will be, however if you have a uneven lawn then a physically bigger mower (with larger wheels) will cope with the lumps and bumps better.  

In general, try and go for the smallest mower you can that will cope with your lawn.

Noise

Most robot mowers are in the range of 50-60 dB about the same volume as normal conversation.  Petrol mowers are mostly in the range 90-100 dB.

Remember that the level of noise decreases as you get further away – doubling the distance decreases the measured noise 6dB so a 54db mower that is 1m away will be the same as a 60dB mower at 2m (assuming they are measured the same way).