I-Glide battery charge, or Next, even Tailwind

[cadamson]

That makes sense on the fancy charger. Can you tell I struggled in semester 2 of physics? Part of my Ph.D. dissertation, however, was characterizing neurons electrophysiologically (voltage-gated channels) as well as immunohistochemically for ion channels (potassium, K+ variants), I visualize biology better than hmmm, electrochemistry, much less engineering my own battery.

So how long do the Li battery charges last? And Nonoise and Maddog, do you both still have old tailwind/iglides? When you converted your batteries, was there a concern about voltage and cpu damage?

[nonoise]

...
So how long do the Li battery charges last? And Nonoise and Maddog, do you both still have old tailwind/iglides? When you converted your batteries, was there a concern about voltage and cpu damage?

I have a I-Glide spare here that I made up from some new surplus cheap NCM lithium cells. It is not a great battery, only use it for backup, but it has been idle for at least two months and has only lost 0.1 volt.

I use my I-Glide everytime when I go outside and first thing for a short time in the morning and evening downstairs before transferring to my stairlift. I'm pretty sure maddog has both working versions of I-Glide and tailwind.

I was very concerned about damaging the cpu when upgrading, but my used I-Glide came with a failed battery and I did not want to go with more MIMH as they are so similar to NiCad which I hate. So I happened on this box of 24V NCM lithium batteries at a local shop for cheap. Using one of those I made a direct battery replacement into the I-Glide battery box. It did not work. I think it was at this point when maddog told me to take the printed circuit board out of the I-Glide battery box. How he figured that one out is pure genius. But there is logic to it because the original battery had a maximum charge of 28.8 V while the lithiums charge up to 29.2. So there is probably a high voltage cutoff on the printed circuit board that we removed.

You are not supposed to switch charger chemistries due to the way they taper off charging rates. I am not so sure that one would get in trouble with a NIMH charger on a lithium battery. You just might need a high AH battery to get enough charge before the taper. Sorry got into something that's been on my mind awhile.

[nonoise]

... Part of my Ph.D. dissertation, however, was characterizing neurons electrophysiologically (voltage-gated channels) as well as immunohistochemically for ion channels (potassium, K+ variants), I visualize biology better than hmmm, electrochemistry, much less engineering my own battery. ...

Interesting because my paralysis is caused by what they call a defect on the Calcium channel on chromosome 1. What happens is K+ gets stuck in my muscle cells which depolarizes inactivates them. It is sort of like a discharged battery since adding K+ to the blood serum will correct the electrics.

[cadamson]

What does this do to your heart?

[nonoise]

What does this do to your heart?

Great question. For almost all of us the only genetics affect is on the skeletal muscles, not smooth muscles. However the heart needs the correct level of K+ in the blood serum. So when my K+ drops too low it shows as a depressed ekg t-wave.

[cadamson]

Wow, that is a challenge. Sensory intact and lose motor?, is there a gradation of symptoms or whole body at the same time? Was this discovered at birth then? What is the disorder called, I cannot quick like find it on chromosome 1. This is just curiosity

[nonoise]

Wow, that is a challenge. Sensory intact and lose motor?, is there a gradation of symptoms or whole body at the same time? Was this discovered at birth then? What is the disorder called, I cannot quick like find it on chromosome 1. This is just curiosity

Yup sensory intact and lose motor. At NIH they would tickle my feet to see if I would wiggle. I hated it, it seemed cruel. Periodic symptoms vary, usually extremities, can be legs, arms, even only fingers. But for me was usually legs, sometimes one worse than the other. Now both legs are permanently gone and myopathy is moving in everywhere else. In my case the disease was not known until 16 when I was totally flacid in ER. Luckily I had a good doctor who figured it out. Most don't as there are so few of us with this rare disease and even at that we are mixed up with something like 20 variants and counting. It's called Hypokalemic Periodic Paralysis. Much of what has been written is full of errors. The ones I trust are hkpp.org and periodicparalysis.org.

[maddog]

Cadamson, did your battery hold charge after your charged it.

[cadamson]

Maddog, sorry, did not see your question before, yes, it was normal again. A week ago it stopped charging (and my toggle looks like it is done for), chair works, but I am down to my battery that cuts off "at the top of hills", so dangerous days ahead.

[maddog]

A local friend is updating his iglide battery and I am helping him get the parts. If everything goes as planned it should be a much easier conversion. I have to wait several weeks for parts to come from China but we should have it together by the end of March. If it works well I may sell partially assembled DIY kits to switch over to lithium.

[TREA18]

#maddog How did things go with your last idea? I'm really curious as well as wishing we had the ability to rebuild/build these chairs, that's my next concern. I really love this tailwind and know it won't last for ever with the first concern being the rear wheels and push rim assembly and then the brains. Thank you all for being great assets for the battery ideas.

[maddog]

I built a battery using 18650 cells along with a Vruzend kit to put them together to keep from needing to solder, also once built the cells can be easily replaced later for about $70. I used LG MJ1 cells but have not been overly happy with the results. Using 14 cells gave me 20A and 7ah which should be fine but once the battery dropped down to about 25% it struggled to maintain voltage under load and the chair would keep cutting off. The battery does fine from 100% down to 25-20%, it would just be nice to be able to use the full capacity.

I am building another one right now with Sanyo NCR18650GA cells to see if they perform better. I wish I had gotten the 15A Sony VTC6 cells instead. They would only provide 6ah instead of 7ah but I think with a higher amp rating they would perform better when the battery is low on charge. Even with a lower overall capacity it may last longer if it can hold its voltage under load better throughout a full cycle.

The battery does work with the iglide circuit board left in place. I am running out of old batteries to open and the box I opened for the MJ1 cells would not show the lights on the back of the battery when you pull the handle. The tailwind reads the battery as completely dead and flashes 1 red light on the gauge, however the power level switch does work. This last battery I am building is my last old battery I have and I hope the lights on the back work which should make the tailwind gauge work.

Here is what the battery looks like along with the 3d printed lower half of the battery box.

[TREA18]

That looks really good. Nice job

[nonoise]

Hey pioneer, I should have a case here I can send you, maybe yours. I thought I had two semi pristine ones but only see one. Get back to me if you want it.

[nonoise]

...I am running out of old batteries to open and the box I opened for the MJ1 cells would not show the lights on the back of the battery when you pull the handle. The tailwind reads the battery as completely dead and flashes 1 red light on the gauge, however the power level switch does work. This last battery I am building is my last old battery I have and I hope the lights on the back work which should make the tailwind gauge work....

I should have one case with printed circuit board still intact here if you need it. Get back to me.

[TREA18]

I have some cases, too.

[maddog]

I should be ok for now on any extra battery cases. I have my 9 year old niece putting them together and she is starting to get over the whole battery building excitement. I would like to see if I can get a battery to fully work with the lights but right now it's not a huge priority. If needed I still have my Tailwind battery that holds a small charge and the lights still work on it. I don't now what causes the battery gauge on the back of the battery to stop working. When I connect the new battery the lights all turn on but the handle won't make the gauge turn on. So I know the LEDs still work, the handle just won't activate the gauge. The gauge is activated by a small magnet in the handle. I have tried waving a bigger magnet over that area but it did nothing. I also think there may be more to it than just the handle not activating the gauge because the tailwind can't read any state of charge from the battery either. It has nothing to do with lithium because I have had the same issue sometimes when recelling to nimh. I think they may go bad if they sit dead for a long time, like there might be an internal battery on the circuit board that goes dead if the main battery stays dead for an extended time.