14S cordless tools on a 14S ebike pack

[spinningmagnets]

EGO and Echo have batteries that are verified to be 14S. When fully-charged they are both 57.X volts, with both charging to roughly 4.1V per cell. Each system has a family of tools that the same battery can power, such as a weed trimmer, grass mower, chainsaw, leaf blower, etc. The Snapper gardening tools have a battery pack that is almost identical to Echo, and I have not verified that the Snapper is 14S (the factory approved youtube shows 30 cells, so its likely 15S / 2P). DeWalt has a 60V line of cordless tools, but I finally found out they are 15S. Their labeled voltages are :

56V__EGO
58V__Echo


The Echo cells are clearly labeled "LGDAHD41865" there is a second row of number/letters on each cell, but they are different for each cell. The EGO cells have a secondary cover over a "phase change" sleeve for heat leveling (so the part number isn't evident in the video). I assume the phase change sleeve is similar in composition to what Allcell uses. It turns from a firm rubbery feel to a soft rubbery feel when it absorbs heat, and then firms up when it cools down.

The EGO cells are likely the 20A Sanyo UR18650RX https://endless-sphere.com/forums/viewtopic.php?f=14&t=61642#p1087645

Here's a 20-minute teardown video for the EGO and Echo battery packs.
https://www.youtube.com/watch?v=lRdBS9oFUXc

The Echo has no apparent air vents, which may be because it also has a bare BMS board. The EGO has a fully potted BMS, and it does have obvious air-vents. Also, when the EGO motor is spinning, the battery mount has a fan that actively flows air through the battery pack, very impressive design.

My interest in these has to do with the fact I that have two large ebike battery packs that are 14S. em3ev calls theirs 14S packs "50V" and Luna calls them "52V". Manufacturers often don't like customers using batteries from one vendor to power their tool, so sometimes their tools have an extra wire that sends an ID signal. By that I mean that I don't know what it would take to get a 14S ebike pack to power a cordless tool from EGO, Echo...but at this point we do know the voltages are the same.

Their entry level packs are 2.0-Ah of 1S, so the cells are 2000-mAh, and definitely medium-to-high amps. They are very impressed with themselves when they state that their big pack is 4.0-Ah. When my 17-Ah 14S pack wears to the point that I am only able to access 12-Ah of range...I can start using it on my lawn tools, and I will still be able to have three times as much run-time as their "large" pack (likely worn in a backpack).

This is all experimental at this time, do not attempt this if you cannot afford to accidentally damage your cordless tools.

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Some of you may know that DeWalt has a line of "flexvolt" 20V / 60V batteries, that are 5S / 3P / 6-Ah, or can be seriesed/paralleled to 15S / 1P / 2-Ah, so when charged to 4.1V per cell, they will be at 61.5V (using 2000-mAh high-amp cells). Since the battery packs are the part that has the LVC and protection circuits, it "might" be possible to use a 14S ebike packs on a DeWalt cordless "60V" tool. If you try this and the tool shuts down way too soon, then the tool also has an LVC.

http://toolguyd.com/dewalt-flexvolt-answers/

The 60V Snapper tools have a youtube that indicates there are 30 cells, so its likely 15S / 2P

 

[nutnspecial]

You've titled and cover the 14s small capacity tool batteries, but then focus on replacing them (for tool use) with worn ebike packs!

While that's a perfectly valid and a great idea, have you overlooked that these 4ah packs are an EXTREMELY competitive small battery offering for our entry 48v systems?

I picked my echo 4ah up for 75$ including charger. . . . Used- like new. Not only is the construction more advanced than most ebike packs I'm aware of, but they can be backed by up to a 5 year warranty!! My single battery has been good for >4mi of WOT no pedalling over uneven terrain, powering a run-of-the-mill 1kw hub. Not bad for 75$ imo. Or >100$ with 1 yr warranty.

We want to get more people into ebiking (for whatever reason), right? Well this is the best avenue I'm currently aware of, because MOST people are always tight on cash, and also need a reliable and easy to use product. The manu might have had tools in mind, but the batteries are built and priced for the masses! And after all, isn't an ebike a tool? :wink:

-So aren't there some existing threads (and mentioned uses) about these SM?
Imo (at least) links would be appropriate when starting another thread?

 

[spinningmagnets]

I considered that, but the other threads had a different focus, even though there will be some overlap with this one. That is an interesting point about using these packs for ebikes. Doing that certainly side-steps shipment issues. I am told the 80V cordless tool packs are now verified to be 20S (Greenworks and Kobalt), and two of the 4.0-Ah packs would be 72V / 8-Ah.

I am surprised that nobody so far has leveraged these high-amp 36V tool packs to drive a power board. If I was selling a friction drive, these 36V packs are the only pack I would set them up to use. Buy my drive, and then pick up a battery and charger at Lowes, Home-Depot, Menards, etc...so battery shipping and warranty issues would be "not my problem".

I haven't found any 48V / 13S tool-packs, but the 14S tool packs are now mass-produced, and don't appear to be going away anytime soon. If using a tool-pack to run an ebike, I seem to remember paralleling two of them requires isolation diodes so the high one doesn't rapidly charge up the low one (hopefully they both start at the same state-of-charge, and then discharge fairly evenly). I don't know if I stated that correctly, but personally I would have a three-way switch so only one of the packs is being used at a time (#1 on...both off...#2 on), and I would only use the larger 4.0-Ah packs. the 2.0's would likely run hot at ebike amp-draws...

The only place I have found so far that has an exact voltage cross-over is the 14S tool-packs. I know there are millions of 36V ebike kits (and 36V tool-packs), but due to the small Ah size of the tool-packs, I don't consider 36V to be an option due to cell-heat. In fact, I am not too sure about using a tool-pack at 14S on an ebike. However, as long as I have a few 14S ebike packs sitting around, it is a "match made in heaven" to pair it with a 14S yard tool.

Worn cordless tools with a dead battery can be found VERY cheaply, simply because when the battery wears out, a replacement battery is often priced near the cost of a whole new tool and battery set. I believe this pricing model is the result of the fact that the tool companies know the batteries will wear out no matter what they do, so why make the tool so robust that it lasts many years? It is more profitable to entice the happy consumer to re-buy the entire set.

With that in mind, what will wear out on the weed-trimmer I have now? and the lawn-mower I plan to buy in spring? I honestly doubt anything will wear out inside of a decade. On cordless drills, the brushes and trigger are often the first point of failure. The lawn-tool triggers can be bought, or bypassed by a smart ebiker with a soldering iron. Also, this family of tools uses brushless motors (so, no brushes to ever need replacing)

Keep an eye out for worn cordless tools labeled as 56V, 58V (charity thrift store? Pawn shop?). They will likely be very cheap and only need a 14S battery.

 

[dogman dan]

I can't say about the tools you mention,, but worth noting that when I put some 10 ah lipo on a tool that normally came with a 2 ah NiCad,, It allowed me to use the weed whacker continuously until it overheated, which melted the plastic housing that held the motor bearings.

The motor hung in there, I actually still used that tool for small jobs at the house a few years. It just squealed all the time with unhappy bearings. But the run time a 10 ah pack gave me was clearly too long for the tool. Designers figured you'd have two small batteries, and built the tool to run continuously for 30 min, not two hours.

This tool was a B&D, 24v sting trimmer.

Hopefully the new generation of tools uses plastic with a higher melt point.

 

[Ykick]

Where did you find the 4.1V/cell top charge spec for the Echo lawn tool packs? I’ve been charging 4Ah Echo pack to 58.8V. IIRC the stock charger terminated around 58.5V?

As with any lithium chemistry eBike packs I never allow them to sit fully charge for more than a day.

Discharge BMS appears to be handled by the tool.

It works pretty well on my BBS02 Swift folder. Unfortunately, it's hard to find good way to mount it on that frame with only a single top tube. Good little range extender for my other bikes too.

 

[spinningmagnets]

I'm sure the precise voltage varies from one tool charger to the next, but the 4.1V per cell spec was from the linked video, via a DMM (fresh off of a charger).

If the cells in the stock tool-packs are rated for 20A, and they are 1P (the 2-Ah versions). Of course, it could only be used on a low-amp ebike/power-board system. The Echo and EGO both have a 28-cell 2P / 4-Ah version, so that one could be used as a small "limp home" pack, if it can truly provide 40A peaks.

If a 15-Ah ebike pack is old enough that it only provides 10-Ah now, it's too short of a range to do the job it used to do, but 10-Ah is phenomenal for a lawn tool...my stock 2-Ah pack lasts 30 solid minutes of non-stop weed trimming in thick grass.

 

[Ykick]

I'm sure the precise voltage varies from one tool charger to the next, but the 4.1V per cell spec was from the linked video, via a DMM.

If the cells in the stock tool-packs are rated for 20A, and they are 1P (the 2-Ah versions) of course, it could only be used on a low-amp system. The Echo and EGO both have a 28-cell 2P / 4-Ah version, so that one could be used as a small "limp home" pack, if it can truly provide 40A peaks.

If a 15-Ah ebike pack is old enough that it only provides 10-Ah now, it's too short of a range to do the job it used to do, but 10-Ah is phenomenal for a lawn tool...

I see now, 'thought perhaps you were quoting an unknown data sheet which specified 4.1V/cell fully charged.

The published data for LGDAHD41865 cell is 4.2V +/- 0.5V

 

[mrzed]

The newer higher end >40v yard tools almost certainly come with controllers with temperature monitoring and roll back or shut off. Even my much older solaris 24v mower that i converted shuts itself down if I get too much clumping of wet grass. I just got the ego 15 inch string trimmer and hedge tool, and they accept the 7.5ah batteries from the mower which would be good for 2 hours plus of continuous runtime. I'd think they have to be able to monitor temp with that kind of capacity.

I'm deeply impressed with the quality of the battery package and motor on these new tools. It's too bad ebikes are not enough of a market to achieve the level of engineering that yard tools are getting.

 

[nutnspecial]

^^And that's the caveat to mismatching the components.
Ebike battery // tool or Tool battery // ebike can be hard on all except ebike. If using the latter combo as I am, one must either manually monitor and mantain health of pack (temp and cutoff voltage), or set up a controller and/or caV3 for those protections.

I must have misunderstood what you wanted to talk about here SM (title changed + discussion so far), my bad!

The utube tear down was ok (and better than I could prob do), but there was alot of supposition and unfounded speculation toward the ego engineering being superior, where it lacked facts and real world info. This was a post on the vid I concurred with:

Wow. A ton of speculation here about what "real world performance" might be. While EGO appears to have a more elegant vented design, there's no evidence that there are thermal issues or deficiencies with the ECHO products so I would hesitate before jumping to conclusions. If you look on eBay there are lots of dead EGO battery packs for sale "as is, for parts", so perhaps quality control in manufacturing is more important? And about actual performance and longevity of the tool(s) in question? Honestly, this came across as a sales pitch for EGO. In real life, the Echo 4Ah battery pack is smaller and lighter and costs less than the EGO. So unless there's a known/proven with issue with the Echo battery, details like that might be worth mentioning.

On that topic I can say mine just got warm with the 1kw setup and a draw down to 3.5v resting cell avg. The kit has a 26a controller which I did the soldered shunt mod on, but I didn't measure how much more it draws. To be safe I'd recommend a single 4ah for up to standard 1kw kit ebike draws, cuz you obviously don't want to beat them if you don't have low voltage or temp cutoffs. I was thinking it would be even more ideal for lower draw 48 systems because range might double or triple depending on the rider/situation.
Also, I am fairly certain that paralleling more than one would be as simple as just doing it? I think they would act the same as any other paralleled bms'd packs or naked lipos?

 

[spinningmagnets]

Dogman, that was a great point about bearing heat at the high RPMs these yard tools run at. The 2-stroke gasser weed wacker at work gets so hot I can't put my hand on it after 30-minutes. I went back and ran a fully charged EGO 2-Ah pack down to dead in about 30-minutes of non-stop cutting (I took it to work as an acid-test, we have miles of stuff to do, but we only keep up around the main office building to impress visitors).

The EGO motor / string housing is aluminum, and after 30-minutes was barely warm. I chalk that up to having a bearing that is properly sized, plus of course, the aluminum to absorb and shed heat. Thanks for the suggestion, I hadn't thought of that, but I am now even more impressed.

nutspecial, I certainly don't want to sound like I was talking down the Echo products. If I found one as a used unit for $20 (with worn out battery), I would not hesitate to grab it, for my sons or a friend. I paid full retail price for the EGO trimmer, based on icecube57's review, and the fact that no local retailer carries the Echo.

edit: the large pack will also run the weed wacker, but....the small weed wacker pack refuses to run the power, even unloaded. There are three blades on the mower battery interface, so that third blade somehow knows...this is relevant because a couple years from now I will be adapting my old ebike pack to run the mower.

 

[dogman dan]

A more professional tool should be able to do a longer run time. I took to buying a new cheap piece of crap B&D trimmer each year. Partly to get more of the NiCad packs, which also worked on drills we had there at that job. But also, we could go back to the tool shed and grab more packs, and swap trimmers. I just killed the first one with the bright idea of a 2 hour non stop run with the lipo packs.

There was a big label of the box,, not for professional use. But typically we needed only 2-3 hours a week of use, not all day every day. I used roundup to keep the grass away from trees and curbs, so what had to be string trimmed was minimal. Just odd spots a mower could not catch, and occasional pop up weeds in the edged dirt areas.