its a start

[expresso]

https://www.youtube.com/watch?v=uKw2OKszqco

its starting - another lithium option on a chair - yes the chair is not for us - but its a start

we have have 3 chairs with lithium options


Bounder - Pride and Amy system

bounder being the best out of the bunch - and using LIfePO4 100ah -

not sure what pride is using - but Amy is not using Life -

small packs - but its a start - maybe in 10 years - it will all catch on and all brands may offer some kind of option

[Burgerman]

Its a start. A very very timid and wholly inadequate start. And a decade after the every other industry. And as you say they might catch up roughly were we were in another decade! By then we will likely be using dilithium crystals or something!

I was looking at quite how practical a small lithium battery combined with one of the low power nuclear energy sources they used on the voyagers and other space vehicles. But running around with a nuclear powered charge system on your chair might scare the natives a bit.

I mean these.
https://voyager.jpl.nasa.gov/mission/sp ... ments/rtg/

Wonder how hard i would be to aquire one?

[expresso]

yes very slow start - has to start somewhere - some how

bounder did it the best so far - correct - just its 100ah - but for most that would be fine -

maybe pride is using LIfe - cant find any info. on it -

amy is not using life - why who knows

it will catch on slowly - hopefully - but will never reach what we do and the Cap. we use - then comes the cost - which is the problem if going with insurance to cover it - at least for the moment - in a decade - that may change also -

out of pocket who knows - cheaper for DIY - but many cant so better than nothing - should move into the real chairs - RWD if any left -

[Burgerman]

Cost is cheaper.

amy is not using life - why who knows

Because it doesent understand batteries. And has been told that lithium ion is more energy dense. And way easier to get to work properly with a BMS. But they burn. Very exitedly. If anything goes wrong. It has happened with cameras, scooters, laptops, phones etc and theres been a lot of issues. Even boeing dreamliner... But in most cases there isnt a disabled person that is unable to get away. If a phone or laptop burns you throw it on the floor. It doesent burn you to death in a massive fireball because you cant get off. Having seen this chemistry do this with my own eyes in many hobby batteries over the last 15 years I have a very healthy fear of the things.

If there was no fire problem, I would build a pack with them myself. But theres a few more problems. They allow you to build a pack that is around twice as energy dense (well not quite but much better). So a smaller lighter pack could be 150Ah. Instead of say 90Ah. But only if you use all of the rated capacity. And if you do that, you get between 200 and 700 cycles. Depending on exact cells choosen. Not the several thousand we all now expect. And they age faster through calender years too.

If you limit the charge voltage to say 4.1V per cell, and limit the discharge to say 3V instead of 2.5V you then have a cell that will last almost as long as a LiFePO4. Provided you carefully control temperature and dont take out big currents too often. Or charge fast too often. But now you only have around 70% of the rated Ah. This is what tesla do. And you still have the risk. One disabled user burned to death because of a lithium ion pack used by Ami, and they will be out of business. And everyone else will then think lithium ion (inc the safe ones like we use) are dangerous... And they will not want to go there $$$.

[expresso]

i have not heard of anyone burning to death using a Amy chair -- where did you read that ?

i like to read it - thats crazy - that will stop others from doing it - not understanding or care to understand the facts around the chemistry -

hopefully pride uses Life - no info or what kind they are using - they should take pointers from Bounder who been using it for years now - Life

work fine - beefy BMS - so far so good - cant complain going on 4 years - Sunrise will be the last of them to get on board if at all - from the way i see them with chairs - they dont care much about the user or which chairs they offer her

V4 RWD - Bounder RWD - thats about it here - invacare also if they continue to sell chairs here - big question -

[LROBBINS]

Expresso,

I think John was expressing a hypothetical. If Ami is using Li ion, eventually there will be a fire ... with the consequences John alluded to.

[Burgerman]

Correct. When it happens they will be up shit creek without a bat.

[martin007]

small packs - but its a start - maybe in 10 years - it will all catch on and all brands may offer some kind of option

In ten years I may be dead.

P.S. 4 wheels are enough.