[ILUG] [Q] broken mouse work-arounds / replacements

[Michael Watterson]

Josh Glover wrote:
> 2009/5/28 Frank Peelo <f26p at eircom.net>:
>
>   
>> Timothy Murphy wrote:
>>
>>     
>>> On Thursday 28 May 2009 08:41:30 Josh Glover wrote:
>>>
>>>       
>>>> 2009/5/26 Brian Foster <blf at utvinternet.ie>:
>>>>
>>>>         
>>>>> I'm presuming the impact of rechargeable[s]
>>>>> is less than the impact of all the non-rechargeables.
>>>>>           
Most studies are for NiCd. Which have about 1000 cycles, but about 1/2 
to 1/3rd capacity of Alkaline.
Zinc Carbon can have 1/5th capacity of Alkaline and are same waste. 
Alkaline work out much cheaper, so Zinc Carbon should be banned as wasteful.

NiMh can have similar capacity to Alkaline, but can self discharge in 2 
weeks rather than 2 months of NiCd. They are also often only good for 
about 300 charge cycles.

For clocks, Microphones, Memory backup and  emergency  torch  the  
Alkaline is best as  storage can be up to 5  years and operation 1 to 2  
years.  NiCd  no  use as it goes  flat,   NiMH  is  even worse.

For Military or very high power the lower capacity NiCd is preferred 
still due to much lower resistance (lower losses at very high power) and 
much slower  self discharge.

NiCd are very toxic to dispose of. NiMh is only slightly toxic.

Lithium batteries can  even be  landfilled as they  are  not toxic.  
LiPoly are  just a  lower capacity  physical structure to  the  4 main  
Lithium chemistries (one of which is not rechargeable.)

* The overall cost in money, carbon and environment  is  much  lower  
for  NiMH and  Lithium rechargeable  than Alkaline.
* In suitable applications even Toxic NiCd and LeadAcid makes more sense 
than disposable primary batteries.

Only 1/2 discharged Alkaline can be charged. Without a smart charger 
there is risk of hydrogen vent and explosion. More than 1/3rd discharged 
won't charge and any attempt is very likely to gas. It makes no sense 
compared with NiMH.

Zinc Carbon should never be used.
Alkaline (or for 5 year micro amp Lithium primary) is best for very low 
current / intermittent / emergency devices.
NiMH are to be preferred over NiCd on grounds of toxicity, though they 
have higher self discharge. The 1/3rd as many charge cycles is offset by 
x3 capacity.
Metal cased Lithium batteries are preferable for new designs, but need 
special charging circuits.
LiPoly is only suitable for shorter life or very compact consumer 
products as  the lifetime is shorter and capacity  is  a  bit less.  
They  are  more  easily  pierced and prone to expansion.
Lead Acid (calcium) liquid, glass mat or Gel are still best for standby 
(UPS) as NiMH or Lithium may fail or lose capacity on float charge, high 
current (car starter, wheel chair etc).  The Calcium technology means a 
12V (6 cell) is nominally 14.2V rather than the traditional 13.8V, but 
means the cell(s) stop passing current on charge and thus don't gas 
hydrogen/oxygen using up the water.





>>>> I hope this is true, as I labour under the same presumption. :)
>>>> Has anyone pointers to research on this topic?
>>>>         
>>> [C]ommon sense seems to me to suggest you are wrong.
>>> Suppose a rechargeable battery can be re-charged 100 times
>>> and holds 1/2 the charge of a non-rechargeable.
>>> Then you would be saying that for some reason
>>> 50 non-rechargable batteries require less re-cycling
>>> than 1 rechargeable.
>>>       
>> As I read it, they seem to be saying the opposite - that the environmental
>> impact of the rechargeable "is less than the impact of all the
>> non-rechargeables".
>>     
>
> That's what I thought Brian was saying as well, and my editing (above)
> seems to support that fact. Once I removed all the supporting clauses
> and qualifiers, his sentence is quite clear.
>
> Common sense would dictate that recyclables have less of an
> environmental impact, but common sense is sometimes, er, a little too
> common. ;)
>
>   


-- 
Mike