Greenworks batteries

I wanted to share some experience with mainstream Greenworks power tools batteries. Although they don’t pack the same energy density as what custom battery builders can achieve with quality cells, there are still a few advantages and are a viable entry-level option for EVs. As long as you know what they can and cannot do.

First, they are widely available, and reasonably affordable (hard/expensive to get quality cells for a battery build, and not that many battery builders in NZ), and trustable compared to dodgy batteries from aliexpress or the plethora of fake cells that abound. Greenworks have their own factories, they produce also for Stihl. That’s kind of legit. And there’s a 3yrs warranty.

Their form factor, fully encased, detachable means that they are quite robust and easy to handle, easy to travel with. (they look much less threatening than a wrapped up pack of cells with some wires poking out it which can easily look like an IED…)
Being detachable, they can fit a few different EVs, they can be removed and separated from the vehicle for storage, charge, etc… Easy to have multiple 3d printed cradles, one on the bike, one on the board (the width of a LY EVO tail), …

Anyway, that’s part of the reason I used them, and I feel reasonably safe having those close to my body.
They’re only 4Ah, which isn’t exactly much, but still very suitable for most of my short range travel. I can milk out about 10-12kms out of them at good fun cruising speed. I pack a second one in my backpack if needed. It also means that for short travels, there’s only limited weight to lug around.

In terms of capabilities, Greenworks calls them 40V, which is of course marketing bullshit targeting people who can’t comprehend the reality of nominal voltage. But to their defence, DeWalt did it first! Anyway inside, you’ll find your typical 10S2P, Li-Ion setup. With cells that can push 20A with a limited 2AH capacity. (yeah, modern cells would outdo that easily). Still 40A is reasonably decent for most usages. I know from vesc logs that I can’t sustain such a draw for too long before I reach uncomfortable speeds. Few seconds at full throttle is plenty for me. (but I’m a pussy, and self preservation kicks in quite early around 40km/h, unlike some of you nutters!)

Link for the cells:

Interestingly, the charger seems to limit the charging voltage to 41V instead of pushing further to your typical 42V, apparently so as to prolong battery life and claim stability over more cycles.

Here are some pics of internals:

Anyway, hope this helps !

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Interesting… I have a mower that uses their 60v pack in a very similar shape. I’m guessing just 50% longer than the 40V version. Definitely looks easy to mount on to a bike rear rack or skateboard top mount.

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he made some nice toy’s with those batteries found him a couple months ago don’t really like the dude for some reason but the builds he made are cool

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Yeah, they seem to move to higher voltages for their power tools, which is maybe why the 40V range is relatively affordable. My ESCs will keep me in the 40V world though…

There’s also a 6AH 40V battery that is made of 10S2P INR19/66 cells (Sony/Murata VTC6).

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Another great deal from battery clearing house that is costly prohibitive / unobtainable for people in NZ.

Greenworks and Greenworks Commercial, from what I had seen when I did a bit of research, are 2 different companies with different (incompatible) tools.
In that form factor, I’ve got a couple of the Hitachi 36v backpacks in a 10S8P config. Fair bit of juice, up to 50A, 21Ah, all in a Ninja Turtle approved package of 6.5kgs…

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Kobalt or ego batteries are a better option if you are going this route… as far as power is concerned

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Thanks for posting your experience with these packs! With cell availability being so limited in some countries it’s always good to see possible different options for an ebike/esk8 build.

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Thanks!
Never seen any Kobalt gear here, but they look good indeed. Looks like it’s a US centered venture. Surprised they didn’t get imported here. Most of my stuff is designed for 10S so the EGO at 56V is out of the question at the moment.

Something important also in selecting those batteries is the way they mate to the tools. Some are simple and go well with 3d printing adapters while others are an order of magnitude more complex to design.

Also, some have some sort of pseudo-clever systems in place to make sure that the battery is “talking to” a genuine tool from that same brand. I’ve read a few discussions about that on Endless-Sphere, can’t remember exact brands/models, but there’s none of that on those GreenWorks!

Anyway, definitely plenty of other options like that out there, depending on your local market.

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I believe Milwaukee, Makita, Dewalt, Snap-on possibly have that, you wouldn’t want a fake battery explode next to your hand and face

yeah I just meant for cells… I would tear the battery apart and re configure it personally.

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How would you make that work for a skateboard? Just solder a xt90 to it?

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have a 3d printed locking mecanism like the one they use on their tools have 2 prongs that goes between the tabs when you insert the battery thats pretty much the only way if you want to keep them stock

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Have a look at:
https://terrafirmatechnology.com/shop

Adapters for many batteries, and source of inspiration for others…

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I’m running the Kobalt 40V 5Ah batteries from my lawnmower for my skateboard—do you know if these batteries typically have their own low voltage protection built in or do I need to rely on the ESC?

I like the 10+ mile range and ability to have multiple batteries ready to go

I think in any case it’s a good idea to have the VESC software in charge of the voltage protection, as it would give some power throttling warning before an abrupt cut off.
If you can identify the cells used in your battery pack, get the corresponding datasheet, and you’d be able to set the right voltage cutoffs. Obviously on small 10S2P packs like that, voltage sag is a concern, so you’re likely to never really get to tap into that last Ah of capacity before the cutoffs kick in.

Good point on the early warning from the VESC cutoff versus just letting the battery cut itself off while I’m riding.

The battery has a button to show charge level (0-4 bars) and my lawnmower consistently shuts off right when it reaches 0 bars so I probably just need to validate that 0 bar voltage matches up conservatively with my VESC voltage cutoff.

In case anyone ever googles it I found out accidentally that the kobalt 40v KB 540-06 battery will give you a red “error” light and won’t auto-charge on their charger if you let the voltage drop to 18.1V.

I manually charged it back up to 19V and the charger started working again.

My problem was I left the battery connected after getting to “0% charge” such that it was still powering the idle VESC (blinky lights on) long enough to go below the voltage threshold.

Probably not good for the long term battery health but a good lesson to learn with a fully replaceable/rebuildable battery like this.

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I’m bummed that the shop @alexnz linked doesn’t have any 60v greenworks. Gonna try and work a system out so I can slide it on to a bike or a jump deck real quick. Maybe make a go kart frame for it too :thinking: