Professional Tool Reviews for Pros

Sun Joe iON 40V Brushless Lawnmower Review

Sun Joe iON Mower
PTR Review
  • Run Time 7.5
  • Power 8.0
  • Cut Quality 9.5
  • Value 8.0
  • Features 7.5

The Sun Joe iON 40V Mower matches up pretty well overall with the competition. The cut quality is outstandingly even, right out of the box. It suffers just slightly on run time and features. We'd like to see a confident 45+ minutes out of the battery and mulching capability to match other mowers in this class. In terms of power and value, the iON is spot on with its competition. Make no mistake though, what it offers in performance, it does very well.

Overall Score 8.1 (out of 10)

Sun Joe iON 40-Volt Cordless 16-Inch Lawn Mower w/ Brushless Motor

Even if we don’t enjoy the work that goes into it, we enjoy a well-landscaped lawn.  And a lawn doesn’t even have to be perfectly sodded, watered, and fertilized to look good – as the drought draws to close here in Florida and the rainy season starts to green up even less-than-perfect lawns, a nice, uniform cut makes it look respectable.


That’s why I was eager to test the Sun Joe iON 40-Volt Cordless 16-Inch Lawn Mower.  I liked that I wouldn’t have to make a trip to the gas station when I ran out of gas, mix the oil, change the plug, introduce an additive to the tank to guard against ethanol damage during the dormant season, and all the other maintenance that comes along with a gas mower.  But could a battery-powered replacement really get the job done?

First Impressions of the Sun Joe iON 40V Mower

After opening the 30”x21”x17” box, you find that a large handle is built into the machine’s frame.  This handle coupled with the iON’s remarkably light weight – just 37.3 pounds – makes it easy to lift.  The only assembly required is to attach the upper handle to the lower handle with the included knob and bolts and then adjust the entire handle with two quick lock wheels.  A grass bag easily attaches to back of the machine after lifting the ejector flap.  The body is made of composite plastics.

Opening the transparent battery cover allows access to the safety key, key slot, and the battery compartment for the EcoSharp™ iBAT40 Lithium-Ion battery.  Once the key is plugged in and the battery inserted, be sure to adjust the deck height to one of six positions (1.18” – 3.15”) using the adjustment lever on the machine’s port side.  This is so simple you’ll laugh at how you cursed the day you were born when attempting to adjust the deck height of your other mower.  At this point there’s nothing left but the mowing.  Pressing the safety lock button and pulling the switch bar lever makes the iON come alive.

Sun Joe iON Mower

Using the Sun Joe iON

The brushless motor isn’t silent but it is remarkably quiet – so quiet that the first thing that occurred to me was that I could easily mow my lawn early on a Saturday morning without fear of disturbing my neighbors who may be sleeping in.  The second thing that occurred to me was loaning the iON to my neighbors so they wouldn’t disturb me when I was sleeping in.

Maneuvering the Sun Joe iON is really a dream – its weight advantage really shines here.  It’s true that the steel blade under the 16” deck cuts a 15” swath – relatively narrow by most mower standards – but Sun Joe does recommend the machine for small and mid-sized yards.  Moreover, it is favorable for a lawn like mine: several narrow areas of grass and many beds and plants to mow around – some so close together that I couldn’t get my gas mower between them.  I always enjoyed taking care of the lawn but using the iON is actually fun.  The cut was crisp and uniform.  I couldn’t help but think of how one neighbor – an elderly widow who is still quite spry – maintains her own lawn.  The Sun Joe iON would allow her to do so longer than would a heavier, gas-powered mower.

Sun Joe iON Mower

The grass bag is 9.25 gallons. The weight of the machine obviously increases as the bag fills, but even when it’s full (the grass bag has an indicator window and flap that is designed to close at that point) the iON is still lighter than its gas-powered counterparts.  I was happy to add the clippings to my compost in the backyard. However, the iON’s lack of mulching capability is notable – especially since many of its peers have this capability.  A mulching blade may be planned but I couldn’t find any information about it.

Note: According to the manufacturer, a mulching blade is planned and already underway in production to be sold as an additional accessory should the user wish to use it as a mulching mower.

Sun Joe iON Mower

Sun Joe says the EcoSharp™ iBAT40 Lithium-Ion battery lasts forty minutes on a full charge and I found it to perform at least that well.  I’ve charged it from dead a few times and it took about two hours each time.  As battery technology improves, we’ll benefit from machines like the iON, but uncertainty remains about battery longevity and replacement cost.  It helps that the iBAT40 has a 2-year warranty.  It also has no memory effect and it doesn’t fade – it runs on full power until dead.  Its replacement, however, is currently $150.

Sun Joe iON Mower


I’ve mowed my lawn three times with the Sun Joe iON and have had a positive experience.  It performs as it was designed with ease.  It will take a long-term review of the machine to see if one of its main strengths – maneuverability based on its light weight – is also a weakness due to breakdown of the materials used to build it.  In Florida particularly, the sandy soil can wear away at plastic and composite pieces.  Its other main strength – powerful battery operation – is a welcome addition to my set of tools.


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Adam Spafford

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