Air-Powered Wheelchair Goes Like the Wind | Hacker News Reader

Air-Powered Wheelchair Goes Like the Wind

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20 pointsseycombi14 comments

Yes it recharges quickly, but equipment to refill 1000+psi tanks is not going to be very common (your garage air compressor can do maybe 150psi). For the mass of those tanks, you could put in a lot of lithium cells, which are only increasing in energy density and in a pinch you can plug into any wall outlet to recharge.

I'd rather sit on 1KW/h worth of lithium cells than 1000 PSI tanks and fittings.

Scuba divers and firefighters routinely go around with 3500psi tanks. The tanks are fittings are very safe. The only real danger is during the filling operation; there have been some rare explosions due to tank corrosion or incorrect aluminum alloys. So competent fill station operators always check for tank inspection stamps / stickers.

But thats only because 1KW/h is an abstract figure where 1000PSI pressure resentment something real in your mind.

We are surrounded by things that can kill us in any number of ways should, the usually poorly maintained, safeguards fail and yet we only really get scared when the "danger" is something "new" or "rare" where the safeguards are actually inspected/maintained.

An exploding tank is way worse than cells in thermal runway.

But thermal runaway is just the novel and rare way electricity kills.

the fact that we are so used to handling lethal levels of electricity that we barely even register electrocution it as a possibility, is exactly the point i am trying to make.

a battery capable of driving a 1kw electric engine is can probably also electrocute you.

I'm not sure I'd agree if I were sat atop the cells with no capability to run away.

A thermal runway event would be way more gradual and there would be time to react. A rupturing tank would pepper you and everyone within 50 meters with sharpnel. Both are very rare events though but still

But it may be perfect for some situations where a high-density energy storage device isn't permissible.

>a high-density energy storage device

Like a tank full of pressurized air?

I'm with you. I already have enough fear when I'm pulling a shot of espresso.

I guess you've never seen Lithium cells burn...

What is its energy efficiency? How much energy do we lose to waste heat when compressing air to 1000 PSI?

What's the speed and distance you can get on those? What about pricing compared to electric models?

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