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Old May 1st 17, 08:30 PM posted to rec.bicycles.tech
Ian Field
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Posts: 250
Default torque wrench issues



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On Monday, May 1, 2017 at 11:34:12 AM UTC-7, Ian Field wrote:

The people who made the RoHS list don't seem very keen on cadmium - like
most battery systems; the cadmium ones got an exemption. However - most
battery manufacturers seem to have voluntarily dropped cadmium. You can
still get them for specialist applications like security systems, but
general types have pretty much vanished from the shops.

I'm not aware of any restrictions on zinc - zinc/air hearing aid
batteries
have if anything, increased in popularity. Because they need air to
work -
they're not fully sealed.


I think that you would find that no one "voluntarily" ceased production
because of health concerns but because Lithium Ion batteries are taking
over the market.


Its difficult to make lithium cells that deliver 1.5V - so not much use for
the standard sizes. I have seen some, but not recently - and they were very
expensive and not rechargeable.

Ni-Mh has largely replaced Ni-Cd and have around 2 - 3x the Ah capacity -
but they can't deliver the instantaneous current draw. Ni-Cd, size for size
have comparable instantaneous current to lead-acid - I've used a Ni-Cd pack
on a motorcycle with electric starter.

When the Ni=Cd battery in my rechargeable shaver gave up, I couldn't get a
replacement for the original, so I tried a Ni-MH - despite 3x the Ah
capacity, it only ran as long as the knackered one it replaced. I noticed
the battery was getting pretty warm - that's where the missing energy was
ending up.

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