[ltp] Re: [PATCH v2] Re: Battery class driver.

Bill Davidsen linux-thinkpad@linux-thinkpad.org
Thu, 02 Nov 2006 12:52:44 -0500


Jean Delvare wrote:
> On 10/31/2006, man with no name wrote:
>> In the case at hand we have mWh and mAh, which measure different
>> physical quantities. You can't convert between them unless you have
>> intimate knowledge of the battery's chemistry and condition, which we
>> don't.
> 
> You just need to know the voltage of the battery, what else?
> 
>> And it would be nice to also allow for power supply devices that use
>> other, incompatible units like "percent" or "minutes" or "hand crank
>> revolutions".
> 
> Do such batteries exist at the moment, or are you just speculating?

I have seen joules (or mJ) on a laptop. Yes, it was Windows, but I bet 
the report came from hardware. Some vendor getting anal about metric?
 > I
> don't quite see how a battery could report remaining energy in time
> units, as power consumption varies over time. Hand crank revolutions
> wouldn't be a very useful unit either, unless you know how much energy
> a revolution provides, and then you can just convert it. Percent would
> make some sense, but you can only express the remaining energy this way,
> not the total. And if you know the total in mAh or mWh, you can multiply
> by the percentage and you get the remaining energy in the same unit.
> 
> --
> Jean Delvare


-- 
Bill Davidsen <davidsen@tmr.com>
   Obscure bug of 2004: BASH BUFFER OVERFLOW - if bash is being run by a
normal user and is setuid root, with the "vi" line edit mode selected,
and the character set is "big5," an off-by-one errors occurs during
wildcard (glob) expansion.