The Sun Joe ION16CS 16-Inch 4-Amp 40-Volt Cordless Chain Saw is part of Sun Joe’s EcoSharp Lithium-Ion platform which includes lawn mowers, leaf blowers and many other great power tools.

In terms of sales, this may not be the best selling chainsaw on the market right now, but it comes with a lot of great features and has a lot to commend it. In this review, we’ll explore this saw in more detail and let you know exactly why we believe it would make a great addition to your power tool collection.

Read on to learn more......


sun joe ION16CS 16 inch 40 volt cordless chainsaw review

Performance and Handling

The ION16CS has been designed and manufactured for felling, bucking and de-limbing small and medium sized trees. It is not suitable for certain other types of work, such as hedge trimming or chainsaw carving. This battery-powered portable saw is best suited for occasional home use and would be suitable for cutting small amounts of firewood or clearing minor storm damage.

According to the manufacturer, the ION16CS has a maximum cut diameter of 14.8 inches, which should be more than adequate for most homeowners’ trimming and cutting requirements. As with many cordless electric saws, it should not be used in wet conditions or in extreme temperatures. The safe maximum temperature for this battery is 45°C (113°F), although you would be a pretty hardy person to be cutting in these conditions!

As with gas saws, battery operated models are portable so you don’t need to be within distance of a power supply to do your work. In general, gas models tend to be more powerful. However, they are noisier, expel more fumes and can be difficult to start on occasion. A friend of mine had a pine tree blow down in a storm. Dealing with it meant doing a lot of cutting and lifting pieces out of the way and during the job he stopped and started his cordless saw well over twenty times. Had he done the same task with his gas saw he would have to have left it running all the time or risk problems when it came to warm starting.

Noise levels are also a factor. Many gas saws produce levels well in excess of 100 dB(A), which risks upsetting the neighbors. The Sun Joe produces a noise level of 90 dB(A), which is the equivalent of a lawn mower and at these levels you can safely operate the saw for up to 2 hours before it becomes a risk to your hearing. This lower noise level makes this saw ideal for use in noise sensitive areas, such as at home as well as near schools and hospitals.

When it comes to handling the Sun Joe, users should find that its ergonomic design and light weight compared to a gas saw (under 13 lbs.), make it reasonably easy to handle for anybody used to working with power tools. In common with most electric saws, the Sun Joe is a breeze to start. You simply need to ensure that the chain brake/hand guard is in the off position, press a lockout button and squeeze the throttle trigger. The saw will start immediately and the lockout switch can be released. Stopping the saw is simply a case of releasing the throttle.

You can discover more about the Sun Joe in the video below.

Cutting Equipment

The Sun Joe is equipped with a 16 inch bar and chain.

The bar is a lightweight Double Guard 91 manufactured by Oregon, so you can be assured of its quality. It has a narrow nose which helps to reduce kickback. As well as this it also has a nose sprocket to assist chain movement but that does mean that you will need to occasionally grease the tip of the bar. This is a simple procedure whereby grease is injected into the bar’s sprocket hole with a grease gun. These can be purchased for around $10.

The chain is a semi-chisel product also manufactured by Oregon. It is one of the most popular sizes having a 3/8” pitch, 0.05” gauge and 56 drive links. It has a hard chromed cutter chain


designed for smooth, fast cutting and to ensure minimum kickback.

When it comes to the cutting equipment there are two important requirements – correct tension and sharpness. On the ION16CS, tension is adjusted by way of a tensioning knob on the side of the saw. This tool-less system is convenient and easy to use. With the battery removed you simply need to turn the knob to loosen the cover and then turn a ring nut to get the desired tension. Full instructions are provided and guidance is given in the manual as to the correct tension needed to ensure best performance.

Second on the list was keeping the cutting components well-sharpened. You will know it's time to do this when the sawdust looks like dust and cutting becomes more difficult. Unless you are used to sharpening your own chains, the manufacturer recommends that this is done at an authorized service center, although there may be other places near to where you live which will do it more cheaply. It’s worth considering the cost of having this done against getting a new chain (which will cost about $20). If you do sharpen the chain yourself you will need a 5/32” round file and holder as well as a flat file.

Design and Construction

This saw is constructed from plastic and metal components.


It has a traditional rear handle design and the battery slides into the top of the unit, which helps to provide balance. The throttle switch and lockout buttons are positioned in close proximity for easy starting. There is a full wrap front handle which allows cutting at different angles and just in front of this is the hand guard. This doubles as a chain brake.

The oil cap is located on the side of the powerhead, so the saw must be placed on its side to add the bar oil. The cap is quite large and easily accessible and sits just above the oil reservoir window.


The tensioning equipment is located on the right side of the saw’s powerhead unit. The picture above also shows the rear guard, offering protection to the operator’s right hand. The saw also has a spiked bumper on the front of the powerhead unit (out of view behind the bar). This helps to provide stability when cutting.

Brushless Motor and 40V Battery

Some of the best electric saws now come with brushless motors. You can read more about this in our article Brushed vs Brushless, but in a nutshell Brushless versions are more efficient and able to convert more energy into power. The Sun Joe scores well in this regard, coming with a 600W brushless motor, providing improved performance.

As well as an efficient motor, the ION16CS comes with a powerful 40 volt, 4 amp hour lithium-ion battery. Voltage provides a rough indication of the saw’s power, with the majority of models ranging from 18V up to 80V, and the Sun Joe is around the middle in this regard. The amp hour rating gives a broad indication of the battery’s runtime, with the higher the number providing longer life. Most chainsaws come equipped with 2AH batteries so the Sun Joe’s 4AH version puts it towards the top of the list in this respect.

In practical terms you will get between 25 and 40 minutes cutting time depending on the intensity of the work being undertaken. You should have plenty of power and life to fell and buck a medium sized tree, though if you plan on doing any bigger tasks it may be worth investing in a second battery.

When it comes to charging, this will take up to 3 hours depending on the level of charge already in the battery. Compared to some of the other models available this is on the slow side, although being lithium-ion you can charge up after use and the battery will still be charged when you next come to use it. A battery charger is provided with this purchase.

The battery itself is equipped with an LED display which indicates the state of battery charge, providing an indication of when you are running low. The battery position is shown in the picture below.


In relation to the battery, one final point should be made. Even though it comes equipped with an iBAT40, the saw is also compatible with the iBAT40XR versions. These batteries are used widely in other power tools in Sun Joe’s 40V range.

Chain Oil System

The lubrication system on the Sun Joe is automatic, removing the need to release oil manually to the cutting gear.

The oil reservoir will need to be kept topped up with a good quality bar and chain oil at all times. The reservoir has a capacity of 2.4 fl. oz. (70 ml). This isn’t particularly large so you should ensure the tank is filled on each occasion before cutting.

Filling the tank is quite straightforward by way of the reservoir cap (as shown in the Design section above). The transparent window enables the user to keep a close eye on the oil level. There is a ‘minimum level’ mark below which the oil should not drop. As mentioned above, a good quality oil should be used and preferably this should be bio-degradable.

Safety Features

The ION16CS comes with plenty of safety features, such as:

  • Reduced kickback bar and low kickback chain which meet the ANSI B.175.1 standards in this regard. This will reduce (though not eliminate) the chances and severity of kickback.
  • Built-in safety lockout button to prevent accidental starting.
  • Chain brake. The double braking system intervenes in two different situations. Firstly, releasing the switch lever will slowly bring the chain to a halt. Secondly, in the event of kickback caused by the incorrect contact between bar and wood, the front hand will push the hand guard forward, automatically deploying the chain brake. This should bring the chain to a stop almost immediately.
  • Hand guards. These protect the operator’s hand from coming into contact with loose and dangerous foliage, as well as from the chain itself.
  • Protective sheath for safe blade storage.
  • Set of bumper spikes. These help to provide stability when sawing.

The safety features, whilst excellent, should not be relied upon solely to keep you safe. Wearing the proper equipment – gloves, chaps etc. – as well as handling the saw properly will ensure user safety.


With the battery attached, this chainsaw weighs 12.8 lbs. Although there are lighter cordless models available, this is standard for this particular class.


When you purchase this saw, you will receive an operator’s manual, an iBAT40 battery and charger, together with a protective sheath for the guide bar.


• Excellent battery

• Tool-less chain tensioning

• Cuts well

• East to start

• Quiet

• No gas fumes


• Battery charge time a little slow

Consumer Ratings

There are only around 30 reviews online for this product, so it is difficult to place too much store in them. Having said this, of the reviews posted there are hardly any negative comments and buyers seem more than pleased with their purchase.

Buyers like the cutting performance, the numerous advantages over gas saws (easy starting, quite, no fumes) as well as the fact that it is a reasonably easy saw to handle. There was a negative comment from a user who mentioned that he had received a defective saw, however pointed out that this was replaced immediately without extra cost.

You should buy this saw if:

• You need something for occasional light and medium cutting duties.

• You want a cordless alternative to gas

• You have other power tools in the Sun Joe 40V range

• You want an easy to operate saw

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• You need something for regular heavy duty cutting work

• You want a budget product

• You want a very lightweight chainsaw.


The Sun Joe comes with a full 2-year warranty which can be extended at additional cost.

Price of Sun Joe ION16cs Chainsaw

This product, when purchased with battery and charger costs just under $250. If you already own other products on this platform and have the necessary batteries and charger, you can buy the bare tool for around $90 less. The saw is priced competitively against others in its class and we therefore believe it represents excellent value for the money.


sun joe ION16CS 16 inch 40 volt cordless chainsaw

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