On Foot Now

It's been a while since I posted. There been some changes because there was a major breakdown.

These machines are built for safety. This one has four batteries and a circuit inside called a BMS (battery management system) and I think something went wrong because I have been doing a lot of stairs which takes its toll, I guess.

I was on my way back home after practicing longer sets of stairs, to the tune of 10 to 15 stairs in a staircase. Suddenly, I couldn't go over 20 km per hour and I had a big red warning on the phone app.

Here we see that I have 91 km remaining on this battery charge. But it wants to go 20 km an hour for 90 kms?

As you can see, it says that battery is nearly full based on how many kilometers I have left to ride. I plugged it in anyway, just to see what it looked like and the charger LED goes red for only about 5 or 10 minutes and then it turns green as if it's fully charged. So something is definitely wrong!

The app allows you to download firmware updates and make adjustments to ride quality, speed warnings if you want to set them. I tried a firmware update first to see if that did the trick. Nothing!

I am amazed that the electric motor did not quit when there was an error. The unicycle got me home with the equivalent of a check engine light going on.

Time to dig a bit deeper

Time to open the hood and take a look inside. These are very compact for what they can do. Motorcycles, by comparison, have the whole section between the front and rear wheels to house the engine, battery, fuel tank and wiring. This has to have all of that stuff above or on the sides of the wheel. Packed in like pringles.

I pulled off the top and set it to charge. The long line of lights is an indicator of the charge level and it was just shy of full, as I said, 91% or so. At least that jives with what the app is telling me.

I can see that there appears to be four batteries that all work together, and there are four different plugins, one heading to each of the batteries.

After doing a little bit of research on the error code, I found out it's actually more like three batteries. The front batteries are 84 volts each, and the two rear batteries it's like one split battery. Each side is 42 volts and together they make the equivalent of one large battery of 84 volts.

The above makes sense if you think about it. The front of the wheel has a lot of room, allowing the battery to occupy the entire height of the machine. The rear has the suspension, shock absorber, and the apparatus that actuates it all. Logically, there is no room for two full size batteries, but the company tries to squeeze all the kilometers they can into a small package.

Further research allowed me to find someone who's having the same problem and they said that you need to balance all the batteries because the BMS doesn't do very well to balance them if they get far out of balance. Apparently charging the battery to full or balance all four batteries.

Next Steps

The steps necessary to get them back in balance, if the batteries are out of balance, is to take all four and unplug them from the main board. I need to plug in the rear batteries, which function as one, and let them charge to full. Then plug in just one of the front batteries and charge till full, then plug in the other front battery and charge till full. The hope is that the BMS will then see them all as full and, as energy is used up, they will all discharge equally.

Below you see the two plugins for the front batteries which are now offline and I will charge the rear batteries as one.

That part of it took quite a while, over an hour, so the rear batteries should be in balance now. That in itself is an encouraging sign since it was only charging for 10 minutes before the charger light went green (prior to disassembly) meaning that it wasn't taking much of a charge. Now, more energy went into the rear!

After that I charged one of the front batteries and it charged fairly quickly, about 15 minutes or so. And now I'm finishing up the other front battery and it just went green.

The XVE light on the charger going green means that the BMS is sensing a full charge in the one remaining battery. This is a three-step process and I'm about to reassemble it and see if all the errors go away.

I would hate to be without my wheel because this vehicle operates with the same set of laws and rules as a person walking, but you have the ability to ride on sidewalks at normal walking speed, on bike paths and bike speeds, and at car speeds on the streets. It's a really great way to travel because, just as bikes are not required to stop at red lights if there's no traffic coming, neither am I. So no matter how bad the traffic is, you can always get where you're going really quickly. And as an added perk, parking is never a problem because you bring it inside with you!

I am hoping to help anyone else that owns this type of Kingsong EUC so they can get back on the road in case they run into the same difficulty.

Wish me luck!