USB charging device for microprocessor knees

Another big step towards more independence as an amputee.
Another big step towards more independence as an amputee.

USB-Charger: Another Game Changer For Active Amputees

Yes, finally it’s out. The USB charging device from OttoBock to charge its microprocessor knees. This is something I have been waiting for for a long time. And looking back at the last 20odd years, this device will be up there among the few items which really broke new grounds for active amputees. After the introduction of microprocessor knees and the first fully waterproof microprocessor devices this charger is another big step to be fully independent. 


Why I Have Been Asking For Such A Device For A Long Time?

Before we get started: Full disclosure: I was given a USB charging device by OttoBock free of charge so I could use and test it in my day to day life.


All people with a microprocessor knee - for any other microprocessor prosthetic device - depend on regular access to a power outlet for charging. Depending on your model, your level of activity, and a few other factors you might need access to a socket every day, every other day, or every three to four days if you are really lucky. This obviously limits the radius of what you can and cannot do.


In my case - I used the C-Leg for 7 years, then upgraded to the Genium, and have been using the Genium X3 for the last year and a bit - a weekend camping trip has never been a problem. A three day trip into the hills was a bit of a gamble. And anything longer was off the menu or needed to be planned with regular stop-overs on campsites. With the possibility of charging my leg straight from a regular power bank, I am now much more independent and can commit to longer treks and longer periods away.


But even when you are staying on a campsite, charging your prosthetic device is often cumbersome. Using a tent, we normally like the more secluded pitches. And most of them are far away from any socket. Leaving a 30.000,00 US$ (or more) device in the shower block over night never seemed like an option to me. Especially as I often don’t take my crutches, so would need to hopp back to my tent on one let, often in the dark, over slippery paths. Again, with the possibility of charging my device directly from a power bank in my tent even when pitched far away from the any power outlet is great news and makes life so much easier.


And for me there is another important reason to celebrate the arrival of a USB charging unit for my knee. Work often brings me to countries with a very unstable electricity supply. Anything from Liberia to Uganda, from Nepal to Pakistan, from South Sudan to Zimbabwe. The threat of an unstable power supply to any electronic equipment is real. Voltage fluctuations, power interruptions, load shedding, and peaks way over 220V when the power comes back after a power cut can permanently damage any electronic device whenever it is plugged in. Now having the chance to charge my leg from a power bank instead of plugging it directly into the main power supply eliminates the risk of losing it to voltage fluctuations. 



What Is This New Charging Device?

The new device basically consists of four parts: A power bank, a USB C to USB A cable, the actual charging adapter, and the - in my case - inductive charger that connects to the microprocessor knee. Please be aware that not all of these parts are included when you buy the USB charger kit. This package only includes the charging adapter and the connecting cable. You need to get your own power bank (which is great, actually, because it means you can get the ones you like and that meet your needs. And it means you can have more than one.) And you need to disconnect the charger (so the piece that actually connects to your leg) from your usual charging unit and re-connect it to the USB charging adapter. 



My Verdict So Far

So far I have only used the charger a couple of times and did not yet test it thoroughly. But my verdict so for is:

  • it’s easy to use
  • works with a wide variety of off-the-shelf power banks
  • it packs rather small and easily fits into my backpack
  • it allows me to stay away for longer
  • it allows me to quickly charge my leg if I run out of battery on the go, even in my day to day life and not just off the beaten track
  • it takes away the worry of destroying the leg while charging in countries with an insecure and fluctuating electricity supply

The only draw-back I see at the moment is that the kit does not include the actual charger (the piece that connects to your microprocessor knee) so you do not have a complete second/spare charging device but need to with this piece in between the USB charger and your normal charger with a plug.


But apart from this one issue I am really satisfied with the new charging option and think it will be a game changer for me and my activities. I have planned a four one week hikes this year and the new USB charging unit will be part of my kit.


I have not yet tested the charger in cold conditions, though and need to see how it performs then.


Okay, so far for now. I will use the charger over the coming months and will give you an update on how it performs in a couple of months.



Post by Bjoern Eser. Bjoern is the founder of The Active Amputee.