In our last issue we talked about the cheap Chinese copies of the high-end Mellow Drive that are entering the market – even before the original item. This is scary, and not only for companies like Mellow that are being ripped off. It should also get the skate community thinking. There must be consequences for counterfeiting a product and bringing it to the market within a timeframe of as short as six months, in a world where normal development cycles for such products take several years.
When Mellow got the chance to analyze one of the rip-offs in their lab in Germany, plenty of dangerous facts about the product surfaced. By looking very similar to the original, the copy is obviously trying to suggest that it’s a quality product. But looks can be deceiving.
In late 2015, so-called hoverboards became notorious after hundreds of units caught fire in their owners’ homes. This left consumers in shock at best, and with damaged or destroyed homes in some cases. Over 500,000 hoverboards were recalled in the USA. The reason for these dramatic events revolved around the use of lithium batteries inside the boards.
What most people don’t know is that lithium batteries have a higher energy density than dynamite. This makes them an extremely bad thing to mess with. Several different safety systems are needed to make a battery pack safe, ranging from temperature and current sensors to voltage measurements in order to avoid overcharging and deep discharge. There is no room for error, as mistakes and shortcuts can lead to alarming problems such as overheating or fire.
In the model Mellow tested, some of these crucial safety features are missing. There are no temperature sensors within the battery pack that would allow for a shutoff in case the battery overheats. This could also reduce the lifetime of the battery, since a lithium battery should not be exposed to temperatures over 60°C. Above this temperature, the battery becomes permanently damaged.
When developing a skateboard battery, one must choose a cell that is able to handle the needed currents. Every cell manufacturer gives a specification for their cells, which normally makes the process of choosing the right cells very straightforward.
However, in the rip-off product, the designers seemed to have ignored or disregarded the proper specs. The Samsung cells they used were rated for a maximum discharge current of 20A, but under full load, the board drew up to 37A from the pack – a serious discrepancy.
The problem wasn’t the batteries themselves; it was the way they were used. Even the best cells will give up quickly if you run them out of their specs.
Besides overburdening the batteries, the rip-off product also lacked a fuse that could shut off the battery when things get out of hand – again, a combination that could result in a fire.
On the mechanical side, the counterfeit product had no cell holders in the pack. Cell holders mechanically keep the single cells in position to avoid damage if the pack is dropped. Especially in skating, one should expect plenty of slams and vibration, making this a “must have.” Without a cell holder, you’re practically asking for problems to flare up.
Another much-discussed topic in electric skateboards are the brakes. Everyone knows that a car without reliable brakes is nothing but dangerous – but with some electric skateboards, reliability still seems to be sort of optional.
Like most cars, e-skates offer what is called “regenerative braking.” During braking, electricity is generated by the motors and charged back into the battery, extending the range. That’s normally a great feature. But when the battery is fully charged, it can’t accept that excess energy; it has to go somewhere else or the brakes will be switched off. For this reason, Mellow has an integrated braking resistor that turns excess energy into heat and dissipates it over a heat sink. The Chinese copycat also looks like it has a heat sink – but it’s actually a fake. When the battery is full, the brakes are simply switched off, leaving the user in a potentially lethal situation.
Since wear and tear is inevitable in skating, reputable companies strive to make trucks and boards as solid as possible. Here again, the copycat demonstrated a flawed design. First, the axle does not go through the hanger. Rather, the motors are attached to the hanger via two round flanges plus three screws. And second, those three screws are not what you’d call over-dimensioned. As a result, the hanger/motor assembly soon starts to bend under the rider’s weight. Imagine jumping off a curb and having to trust your health to a 4 mm screw?!
So, as we mentioned at the top of this article, electric skateboards pose their own set of issues. It’s vital that you don’t just explore what you see on the surface but take the time to look under the hood.
If we just wanted to get from A to B we’d take the bus. Mellow is about the real concrete surf. These are some of the most important key features of the Mellow Electric Skateboard Drive: 1. Fits on any Board 2. 40km/h Top Speed 3. Dual Breaking System 4. Made in Germany, 2 Year Warranty 5. Water and Dust Proof 6. Swappable Battery Pack, Powerbank, Air Travel Approved 7. App Support 24/7.
Special thanks to Michael Brooke of Concrete Wave Magazine.