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Greenworks G-MAX 40V 4.0Ah Li-Ion Battery

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Product overview

The Greenworks G-MAX 40V lithium-ion battery system delivers longer run time, higher performance, and greater output among all Greenworks G-MAX tools.

About Greenworks The future is here and it's electric. Once you’ve experienced the power, convenience and economy of a 40V garden tool there will be no going back. The G-MAX 40V Li-Ion range from Greenworks is already a best-seller in the US and Europe, now it’s ready to revolutionise the way Kiwi’s take care of their backyard.

Greenworks tools are clean, green, quiet and maintenance free, with no compromises – experience the future today.

• 4.0Ah, 40V Lithium-Ion battery
• Compatible with all products within the Greenworks 40V range
• Fast charging
• No memory effect
• No self-discharge
• One Greenworks G-MAX 40V battery powers all Greenworks 40V tools
• 3 Year Greenworks Battery Warranty

Product code: 2927007
Model: G40B4
Voltage: 40V
Charging time 100% (4Ah): 120mins
Battery pack capacity: 4Ah
Watt hours: 144Wh
Weight: 2kg

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Our friendly and knowledgeable gurus are trained to answer all your questions as quickly as possible. So if there’s anything you need to know just give us a call during business hours, or send us an email any time.

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Questions and answers

5 votes
How many discharge cycles is it rated for?
Up to approx 2000.
By Trade Tested on January 20 2020
0 votes
Is the 4.0Ah compatible with the polesaw and hedge trimmer? Will it fit in their housings?
Yes the 4.0Ah battery is compatible. As long as you are using a 40V Greenworks battery on a 40V Greenworks product then it will work!
By Trade Tested on November 27 2022
1 vote
How much time does the battery last for before it runs out while in use?
This is not an easily answered question, this is rated at 4Ah (amp hours), which means it has enough charge to run for an hour when a steady current of 4A is being drawn. However in practice no tool really runs like this - it depends on power needed to run the tool and loading required by the job. So even on the same tool (say a chainsaw) the run time will change depending on the hardness of the wood etc.
By Trade Tested on January 05 2021
1 vote
Is it a direct replacement for the 2 AH unit and does the charger suit both 2 and 4 AH Batteries?
Yes to both.
By Trade Tested on March 26 2020
0 votes
Will this battery operate the 18V LI-ION Hedge trimmer and the Blower Vac G-Max 40V LI-ON?
This will only operate 40V.
By Trade Tested on December 29 2021
-1 votes
Yes it will.
By Trade Tested on November 15 2021
0 votes
Hi will this be suitable to replace the Ryobi 36v battery and if so will the ryobi charger work with it?
No it won't, these are not cross-compatible with other brands (and vice versa).
By Trade Tested on May 20 2020

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All reviews (109)

Read reviews that mention

  • one battery
  • recharge
  • 4 amp
  • greenwork lawnmower
  • 2.0ah
  • whole lawn
  • large lawn
  • job without
  • one go
  • mowed
Good back up battery

Got this as a back up for the Greenworks lawnmower and it works just fine for when the lawn is a bit wet or thick and needs a bit more than the main battery

Evan Allen Manawatu
Greenworks G-MAX 40V 4.0Ah Li-Ion Battery

Works as it should. Great to extend run time for power tools

MA Northland
Green Works Batteries

Great batteries for your mower. Just charge them up and then pop them in your mower. I bought two so I could change them half way though lawn needing mowed if needed. Fantastic.

Happy Customer Auckland
Happy, I guess

I've purchased another 4.0Ah battery the current 4.0Ah battery is insufficient. It's not a large lawn and only takes her about 20 minutes but another battery, or perhaps a higher capacity battery in the first place.

Ken Auckland
"SPARE' Battery

Having a Greenworks chainsaw and Outdoor Vac, prudent to have 2 batteries.....highly recommended

On the level Kapiti Coast
Green works G-Max battery

Good service and great buying

Mel Manawatu

Great addition to my lawn mower meaning my lawns get. Mowed without a recharge in between.

Brods Carterton
Greenworks lithium battery

Very good product that does what they say it will do.

CT Wellington
No, I do not recommend this product.
40v 4ah Battery

This has failed The issue is the poor quality of individual cells used.

Bert Northland
Reply from Trade Tested This unit had a fault and we have sent a replacement product.
Battery Purchase

This is working well and very pleased so far

Alani BOP