My readers are invited to submit educated guesses in the comments. Solution in a week.
Update = solution 17apr2019
Congratulations everyone!
Changeable rechargeable batteries for
electric motorbikes.
In rechargeable battery design, there are various properties to optimize, in no particular order:
In rechargeable battery design, there are various properties to optimize, in no particular order:
1 Non-dangerous materials (not flammable, explosive,
corrosive, toxic),
2 High temperature range the battery can be used,
3 Low self-discharge,
4 High number of cycles,
5 High energy density (kWh/kg or kWh/l),
6 Low price,
7 High charging and discharging speed (e.g. a Lithium battery for a
drone will be discharged in 20 minutes, try that with a lead-acid starter
battery for a car and it will start boiling and deteriorate),
8 Good resistance to over- and undercharging (nowadays not a
problem with microprocessor controlled charging and discharging).
It’s like squeezing a balloon, you optimize one, but lose
another.
I always wondered why electric cars have batteries built in.
Before cars, there were changing stations for horses, why not change the entire
battery? Charging and discharging is controlled by microprocessor, so unlike
used cars, all batteries are the same. Or the user does not own the battery,
rather rents it.
And here in Taipei, finally, I see a charging station for
replaceable batteries for electric motorbikes! That takes charging speed out of
the properties to optimize (it doesn’t matter if it takes 2 or 10 hours).
All of my mobile devices (laptop, camera, mobile phone) used
to have removable batteries. That allows me to take out the battery to reset
the device (and all three had such severe software failures that only taking
out the battery helped). And batteries are the most fail-prone part of a mobile
device, not just losing capacity, but danger of leaking and destroying the
rest.
Recent case: a hook-up in Bangkok brought his scientific
calculator to my room and asked me for new batteries. I took a close look and
beside AAAA cells to power it, I saw that there is a button cell that has
leaked and was surrounded by a crust of salt, and probably corroded the printed
circuit.
My previous mobile phone (Asus Zenphone) has a minor battery
failure where after two years the battery lost capacity (now at about 1/3rd
of original capacity) and started bulging. The bulging became so bad that you
could see the screen bend. In the end, I had to cut off part of the back cover
to give the battery space to bulge.
Removable battery is one of my major requirements for mobile
phone. I think the higher complexity/weight/size (customer can open the case) more than
compensates the inconvenience of having to go to a shop to replace the battery,
or even worse lose the phone due to leaking battery. A friend used to have two
batteries, and kept one fully charged at home, and swapped them when he went
out so he always left home with a full battery. Alas current phones all seem to
have battery built in, and so has my new phone.
Copyright 2019 ChristianPFC
Copyright 2019 ChristianPFC
Charging station for e-scooter batteries
ReplyDeleteAgreed. Charging station for e-scooter batteries.
ReplyDeleteZ
Correct. Congratulations everyone. There is no prize. Details and musings about batteries as update in the original post.
ReplyDeleteHi Christian
ReplyDeleteWe agree on batteries in phones. It is bad for my wallet and bad for the environment to have to replace a phone because the battery has failed. The EU has interfering legislation banning filament light bulbs and banning high power vacuum cleaners for example. What they really need to tackle is mobile phones and there are too areas to deal with:
1 Make replaceable batteries mandatory & max price Eur20 or 5% of the phone price.
2 Make it illegal to slow down a phone or tablet with software "upgrades". This is another evil way of making consumers upgrade way too early.
Z