Huh. Would you believe CE and UL logos?: http://www.dhgate.com/product/led-light-bluetooth-hx-brand-x1-suv-off-road/261697639.html
I’m sure if you ask about balance leads, they’ll tell you these are self-balancing — you don’t need to lead them ….
That’s a different product from the one that I purchased, the dealer of my hoverboard made no such claims. However, as to the general subject at hand, your comment is on point. I, too, find it difficult to believe that particular advertisement’s claims of “We have MFI, UL, CE, FCC and ROHS Certificates.” :~
As to asking the dealer about the leads, I doubt that I would get a satisfactory answer. First, because of the language barrier. Communication of such details would probably get lost in the translation. Second, because I purchased the item from a trading company, not the manufacturer. At best, I’d be getting fourth-hand information. And regardless of their answer, I wouldn’t trust the reliability of the response.
I see what you did there. H)
i looked at plenty of pics of the scooters and replacement packs.
none show a hint of any bms.
no signs of an internal board,balance leads,nothing.
add in the typical cheapest parts that are used in such a device of which the pack is one of the more expensive parts and we know why these are blowing up.
I saw discussion — mentioned it in the earlier Hoverboard warning topic here at
that said while these come in apparent great variety of names and boxes from what seems to be many different companies, they’re all from a few big Chinese manufacturers originally, all made by the same people.
Kind of like Chinese flashlights, apparently.
That’s not reassuring about the quality of the work inside the boxes.
There’s a reason, in fact. None of the good manufacturers of li-ion cells sell them for individual use.
They are meant to go into battery packs with proper protection circuits and charging systems.
And those protection systems — after a lot of fires from Chinese phones in China and from battery packs from Apple and HP and other big companies — have been fairly well worked out.
We’re not getting those. What we get are cells from good sources via third parties, or cells from fly-by-night builders also via third parties.
Sometimes they add some kind of protection circuitry, or something claimed to be that.
This is why I buy cells from Mtn — he specifies exactly what product is added to what cell.
Cheap electronics fail. Protection circuitry is very thin electronics shrinkwrapped over an original cell.
Remember the “li-ion factory” whose representative came on here — we never tracked down the location of the factory, as far as I know.
Apparently in Shenzen from the userid.
That was at: Review request for HKJ [Rechargeable Batteries] on Wed, 07/08/2015 - 06:05 #676
if you use 300 links per page it’s Review request for HKJ [Rechargeable Batteries]
The rep wrote about the “poor Chinese workers” whose hands were black from handling the chemicals, and wrote that they were always experimenting to try to find some way to improve the cells coming from their factory.
I said at the time that was a recipe for disaster —- you can’t safely change the components and chemicals without long life cycle testing. But you can sure make an extra penny per cell (or, yes, get a higher amperage figure, for a while) by sticking in something a little cheaper than the specification calls for.
Haven’t heard from them lately. Hope they didnt’ blow up.
By the way, this enormous variability in components is one longterm problem with the whole li-ion industry. People don’t know what’s in them, you can’t rely on them being the same product — partly because the good manufacturers are trying hard to make them safer and better; partly because the cut-rate manufacturers are putting all kinds of shit inside the shrinkwraps and selling them.
http://www.google.com/search?q=“lithium-ion”+battery+degradation+recycling+components
Thanks for the breakdown photos 1dash1. Other than the battery pack, that sure looks like a nicely build hover board.
Are those li-poly ‘bubble bag’ batteries, or are they shrinkwrapped cylindrical cells?
Lots of sharp pointy edges in that environment, if they’re the bubble-type batteries that blow up like balloons as they get older.
Hm.
I wonder if we’re going to see an era of drones catching fire in operation and falling flaming out of the sky ….
They appeared to me to be shrink-wrapped cylindrical cells, but I’m not absolutely certain because I couldn’t access the battery packs without unhooking the wiring harness.
So far, my son is enjoying his hoverboard very much.
Rules:
1. No helmet = No hoverboarding.
2. No hoverboarding in the house.
3. Only Daddy allowed to recharge the hoverboard.
The initial charge took about two hours. Each subsequent recharge has been about an hour (plus or minus). My guess is that my son has averaged somewhere between 5 and 10 kilometers per day. No problems noticed during any of the recharging cycles. No discernible heat noticed in the battery housing area, but that was to be expected due to the large amount of airspace separating the batteries from the surface of the hoverboard. The charging unit (transformer) heated up to perhaps 115F, very warm to nearly hot. I’ve terminated charging of each cycle as soon as the light turns green.
I’d suggest recharging away from anything flammable. Open area of a garage would be good.
Personally, I’d recharge in a metal box, lined with a few ceramic tiles. Since it contains unknown brand cells, charged in series (possibly without balancing) and it’s also unknown if the charger does cc/cv with real termination / no trickle charge after full. You know, it’s a large pack of cells. If they vent with flames, it would really be best if any flames were contained without you needing to go near it. Li-ions vent hydrogen fluoride (hydrofluoric acid gas), you want to keep your lungs far away from it.
Seriously. ’oogle that.
Someone needs to build a very simple-minded robot that watches a red LED and when it turns green pulls a plug out of the wall.
Because paying close attention to a charger outside on concrete is — unlikely.
Well, I suppose with a good metal box lined with tiles or fire bricks, you could charge it right next to you and keep eye on it’s indicator light. Drop the lid and run if the batteries decide to get nasty. 
But you could also keep in the garage and plug the charger into a timer.
I don’t know, if you’re going to build a circuit to cut power when an led goes green, I’d feel the urge to do a little more. Do one that monitors voltage and current inserted between the charger and the device. Give it a max time for the cv phase then cut off. Also overcurrent and overvoltage cut off.
What kind of charge indicator light do they have? If it’s really a combined red / green light shining through a single hole then you would already sort of need the intelligence of a microcontroller rather than a more simple circuit.
I’ve been recharging the hoverboard in the middle of my garage floor.
Truck Chest Box purchased from Amazon . Sorry, no ceramic tiles or bricks line the box.
Power cord and transformer unit dangle out the front, I haven’t figured an elegant solution to this problem.
EDIT: See post no. 70 for the fix.
LED light shows red when recharging, turns green when fully charged.
Electric outlet digital timer, new, just installed this evening. (Thanks Halo… for the timer idea!)
Movie actor Russell Crowe learned today that airlines will not allow them on planes. I hope they are banned everywhere. 
I wouldn't be caught alive with a hoverboard. 0:)
1dash1,
Nice box!
~ edit ~
Just clicked the amazon link. Wow, spendy box.
That arranged can be :bigsmile:
That's what he said. :evil:
Well, the bad news is … the hoverboard is being banned in just about every corner of the globe.
The good news is … mine is the only kid on the block who has one! :evil: