Showing posts with label lithium. Show all posts
Showing posts with label lithium. Show all posts

Friday 24 September 2021

New batteries

Approaching 8,000 miles on my wheels I am conscious my batteries are nearing the end of their life. Genny's power unit is a Segway, complete with a pair of 72v 5.2Ah Lithium-ion batteries. Getting new batteries is complicated as they are consider dangerous goods. The movement of lithium batteries is subject to regulation by the International Air Transport Association. Segway going bust has added further complications to replacing my tired old batteries 

After loads of research I have purchased a pair of ultra high capacity (UHC) batteries from a clever man who makes them in northern Switzerland. These are new batteries made with the same technology but a more modern build with higher capacity cells. To get these batteries I needed to drive across Europe and collect them in person

Map showing my route from St Malo to Saint-Jean-Pied-de-Port in the SW French Pyrenees via Switzerland and Italy

As I'm up for a road trip and COVID is starting to settle, and having been doubly vaccinated the world is opening again for me. Packing my VW van with mattress, cooker and of course my wheels, I set off for a grand tour and to collect my new batteries

These batteries are built into refurbished cases and there is a trade-in on the old batteries. They are made with a bespoke battery monitoring system that works in a slightly different way but still relies on the standard Segway charging interface. The usual charge indication shown on the Segway infokey reports it's level based on the use of the battery and measured by a built in shunt. The following image shows Genny having used 1/4 of its capacity 

Old picture showing 1/4 battery used and 1000 miles on the clock

The new batteries don't have that same shunt monitoring system and are more variable in how they report their level of charge however they have considerably more capacity. This is of course dependent on many variables like terrain and weight of load. I understand these batteries have powered a Segway i2 for over 92km which is easily more than twice the usual capacity of the standard battery. What I can say is that in my experience, I have been able ride for much greater distance than my old batteries would have taken me. There will be more on this in subsequent posts where I try these batteries on the Comino de Santiago

Graph showing battery capacity

This graph compares the normal 5.2Ah (yellow), a newer releassed 5.6Ah battery (orange) and the new Swiss UHC batteries (blue) and indicates an increase in capacity of well over 200%

Delighted as I am with my new batteries I will probably revert back to my old ones till they finally die on me

Thursday 3 September 2020

Flying with your Genny

Genny is a great travel companion. It will get you places you may not have the energy to access without it and with such a great range on a battery charge it can replace a hire car to some extent. And what style, it will raise eyebrows and get you into many interesting situations and discussions  

We know however that going anywhere with a wheelchair may have additional considerations and getting your wheels into the air can be quite an ordeal. With a motorised chair the issue is more than likely to be about the batteries

Genny comes with 3 batteries. The first is a small 12 volt old school lead-gel battery like you would get in a small motorcycle. The other batteries drive the Segway and are a pair of 5.2 Ah, 73,6  volt Lithium-Ion batteries made with 92 cells each. Lithium batteries have proved unstable under certain conditions and there have been fires on planes because of them. As far as I am aware Segway batteries have proven safe

The movement of lithium by airplane is governed by the International Air Transport Association (IATA) regulations. If your wheelchair is powered by lithium batteries the details are covered in their "Battery Powered Wheelchair and Mobility Aid Guidance Document (updated 2021)" This document is definitely your friend. Print it out and always carry it with you when flying. I also keep a link on my phone just in case. Many times I have needed to resort to this document in discussions with ground operations representatives at the departure gate. I have also spoken to several pilots who have always supported my transportation when referencing the IATA regulations

The issue is that everybody and his mate has an understanding of what the regulations state. From the staff at check-in, the disability advisors on the phone, to the captain, all have their own interpretation and most of it is negative. The word Lithium is a red flag in aviation so have the IATA guidelines printed out and at hand

Once you get past the lithium issue there is another specific design floor with Genny that will also cause havoc. I have several "Acceptance for Travel Guidance" documents that are available on my RESOURCES page that give Genny flying instructions. The problem bit is with the small control panel that puts your legs down. After activation the lights on this unit stay on for up to 8 minutes. This is 8 minutes with the ground operations team twiddling their thumbs and waiting till the lights go off. It is also 8 minutes with you in your aircraft seat watching out the window as they all have a play trying to make the lights go out. Every time someone touches these switches, the 8 minute counter is reset and starts again

Legs down switch control panel

I have 2 solutions for this issue. The first is a small plastic food container that has been adapted to fit the control panel. The switches are then protected and beyond reach of impatient baggage handlers   

Switch protection using a modified food container

The second and much better option, is to fit an additional switch into the 12 volt battery lead that completely isolates the Genny power source. This is a fantastic modification that instantly puts Genny to sleep to the delight of the ground operations crew. This is obviously not an official Genny modification but will greatly assist in airport situations. I have this hidden under the seat and directly above the battery as shown below. Anyone with a simple understanding of electricity would be able to install something like this and it sure beats trying to convince people to wait the 8 mins till the lights go out by themselves. It also helps with children who just can't resist pushing buttons. If you want more details of this solution please leave me a message in the comments space below 

Battery isolation switch (home made)

Another very useful addition is some small wooden inserts I have fabricated. These fit into the side handles that you lower if using a sliding board or to put the legs down in emergencies. These are visible in the following photo and are held in place by 3 cable-ties. I use these just in case a loader accidentally operates these handles. With the legs down Genny is very difficult to move and every time it is lifted, the legs come out more, making it even harder to move. If you want the pattern for these please leave me a message in the comments space below. This would be a good item to get 3D printed      

Inserts that stop the handle operating accidentally

Bon Voyage