Zukun is a product development company, and here they developed a prototype using EGO battery packs, rather than develop their own battery system. To be clear, they did not do this with EGO’s permission, and EGO is not (yet) a business partner with Zukun, plus…these are not actually for sale…(yet).
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Lawn Tool Batteries?
I have written back in 2016 about how so many of the devices in my life are now run by lithium batteries, and also in 2017 about how using cordless tool batteries might be a useful option for powerboards and ebikes, but…which brand and type?
There have been several creative examples (like Blair’s cruiser using three DeWalt 18V packs for 15S / 58V), but we predicted that the EGO brand would be a battery to keep your eye on. They are advertised as a “56V” pack, but they are all made from 14 cells in series (14S), which ebikers have come to refer to as a 52V pack.
Below is a Bafang BBS02 1000W kit that is very well suited to the EGO packs, mounted to an Electra Townie, which is a comfort-posture frame that I like very much for a street commuter.
The Ego system has many different sizes of battery packs in this format from 2.0-Ah up to 7.5-Ah, and they have recently announced that they will soon produce a 10-Ah size. The cell in the 7.5-Ah pack is a Samsung 25R in a 3-in-parallel configuration (3P), and since they are known to peak at 20A each, the 7.5-Ah pack should be able to put out a short 60A peak without damage, and possibly as much as a 30A continuous rate (52V X 60A = 3100W)…Following this pattern, the upcoming 10-Ah pack “should be” capable of 80A peak / 40A continuous. These are a good fit for my favorite mid-drive, the Bafang BBSHD kit.
To make using cordless tool packs easier, the terrafirmatechnology.com adapter shown below can be found by clicking here.
EGO uses high-quality name-brand cells, and they have done four specific things to keep the cells as cool as possible, which is why the EGO packs should last much longer than the other brands.
- Each cell has a PCM sleeve to absorb heat-spikes. PCM is a “Phase Change Material“, and the All-Cell company is famous for inserting their cells into a large block of PCM to help manage battery heat. With this type of PCM, it doesn’t change from a solid to a liquid, it’s more like changing from a hard rubber to a soft rubber, when the cell gets hot. During that process, it can actually absorb a surprising amount of heat. The heat still has to be dissipated over time, but this simple addition limits the highest portion of the working cell temperature peaks.
- Speaking of dissipating that stored heat that was absorbed by the PCM sleeves, these packs have an unusual shape that spreads the cells out, instead of bunching them up in a block. This helps air-circulation, which is vital for the next feature…air-fan cooling!
- These packs from EGO are not sealed, they have channels that allow fans to blow air through the packs when they are being used, and also when they are being charged.
- The last feature that helps these stay as cool as they can be…is their size. The EGO mower does have an UN-exciting 5.0-Ah pack available, but I opted for the 7.5-Ah, which is the largest cordless tool battery pack I have found. A 7.5-Ah is not only the best range of a single cordless pack, it’s size means that each individual cell is less stressed, and will run cooler than it would if you were pulling the same amps from a smaller pack.
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What size is the Zukun?
I want to be clear that this prototype is not in production, so you can’t buy it just yet. It is a childrens emoto, and Zukun has advertised it for ages 6-12. I was surprised that it had a frame-mounted motor, because that makes the system more complex than a hubmotor. However, doing that also makes this model a much better performing ride, compared to using a hubmotor.
If you are looking for an offroader for a 6-foot 2-inch adult, you may need to pay a significant price to get a Zero FX, which performs quite well (there is a small amount of adjustment to better fit slightly shorter riders).
Back in 2018, you could still buy a new Alta Redshift before they went out of business. The Alta was not a dual-purpose, it was a serious full-sized dirt bike, which has been compared to the 450cc class of racers. I am quite sad that they are no longer available, but the Zero company is still on solid ground.
The Sur-Ron line has been quite successful in the US over the past year due to it’s high performance and affordable price. The only authorized US dealer is Luna Cycles in Southern California, and they often have sales with the Light Bee model selling for less than $3900.
The size of the Sur-Ron is well-suited to riders who are roughly 5-foot 10-inches in height (give or take), although, the rear shock mount and forks can be adjusted to fit slightly shorter riders.
If the Zukun Z56 ever gets produced and retailed to the public, its closest competition would be one of the models from the Kuberg company. They make several sizes, and all of them are for riders that are “younger than an adult”, so one of them should match up fairly close. The freerider shown above is smaller and less powerful than the Sur-Ron, and slightly bigger than the Zukun Z56, but Kuberg does have smaller models than this.
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EGO Inverters
Over the last few years, I have grown fond of battery systems that use 48V / 52V, because they can run an inverter during a temporary power outage. An inverter takes DC battery power, and converts it to 110V AC, so it can run household devices, such as the TV, your laptop computer, and the lights.
I already have two large 52V packs that I purchased from Luna Cycles, and if I ever buy a third pack, it would likely be the advanced Luna Wolf, due to the individual cell-fuses and the fact it is fully potted, which provides the greatest possible water and shock-resistance.
In the pic above, Ego has been producing a fairly expensive inverter that accepts up to four of the lawn mower battery packs. It can provide “up to” 3000W of power, depending on how many packs are attached, and which size of pack is used. That is enough power to run your refrigerator, which might draw as much as 1600W peak on start-up (and slightly less than 1000W to run).
Just recently, EGO began retailing a tiny “square wave” inverter for roughly $120. It can produce 110V at roughly 2A from a single socket. It does have two USB ports for keeping your phone or tablet device charged. This is a good development, but I am looking forward for something halfway between these two. More capable than the small one, but less expensive that the large one.
The wall-sockets in the USA for home appliances are typically rated for 110V AC at 15A max. This adds up to 1650W, and this is why the largest home microwaves you can buy are typically 1500W. The common 7.5-Ah EGO pack can safely handle 52V X 60A as a temporary peak, so that equals 3120W. Since it is the amps that most affect the size and cost of inverters, a 1500W size of inverter would be able to easily power any household device (maybe not a refrigerator, but still…). The 7.5-Ah EGO packs could easily provide the 1650W that home outlets are rated for.
It would also be a great benefit to have a “modified sine-wave” output. Pure sine-wave is the best for quietly running sensitive electronics, but I understand that it is expensive. Square-wave is the cheapest style, but it produces a buzzy feedback on many devices. The modified sine wave is a reasonable compromise that can effectively run just about anything that can be plugged into a homes wall-socket.
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The Zukun Z56 is listed as having a 1,000W brushless motor, which puts it in the same class as the EGO mower, chainsaw, and snow-blower.
If you want to keep up to date on any developments with the Zukun Z56, you can find their website by clicking here.
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Written by Ron/spinningmagnets, June 2020
