At 7:52 PM -0800 11/4/2002, Michael 'Mickey' Sattler wrote: >At 22:25 -0500 11/4/2002, [EMAIL PROTECTED] wrote: >> >>My 2000 mAh worth :-) >> >>or your 2aH worth ;-) >>
actually, that is incorrect. batteries are rated by how long it takes their voltage to drop to a certain lavel (I forget what it is) at a certain rate of discharge. For AA batteries, that rate is 1mA (which is why the unit of capacity is mAh. for a car's Lead-acid battery, the unit is Ah). The relation between current drawn & lifetime is not a simple inverse relation. ie, if your battery lasts 2000 at 1mA, it will not last 1000 hours if you pull 2 mA, and if you draw 2 A, the battery will cook within a minute. in addition, as the charge in the battery drops, its output voltage decreases. As the voltage drops, many devices will draw more current, speeding up the discharge process. Each battery has a diffrent set of discharge curves, depending on type & manufaturer. Li-ion, for instance, has a very flat curve: they will do an excellent job of maintaining the same voltage until almost the very end. > >I had no idea about how large of capacity NiMh's there were, I thought such > >high capacity was limited to LiIon. Li-ion rechargeables can have a capacity of up to twice that of a NiMH, but they are not available in AA sizes (mostly out of concern about them exploding like a hand grenade due to improper use (yes, a Li-ion battery is very volitile and have been known to explode) The only standard size Li-ion batteries that I have seen are disposable 9V cells, and they literally have 3 times the capacity of a disposable Alkiline. > >The funny thing is that they last twice what my 1600 mAh cells do. it is possible that this battery company has found some way to improve the discharge curve of their batteries. Also, what is the reated voltage on them? most rechargeables are rated at 1.2V some battery basics: http://www.dpreview.com/learn/Glossary/Camera_System/Batteries_01.htm -- Anton Smirnov [EMAIL PROTECTED] --- Live long and prosper. - Vulcan proverb And eat well. - Jewish addendum to Vulcan proverb Feast on your enemies! - Klingon interpertation of Jewish addendum to Vulcan proverb -- NewtonList is sponsored by <http://lowendmac.com/> and... Shop buy.com and save. <http://lowendmac.com/ad/buy.com.html> Support Low End Mac <http://lowendmac.com/lists/support.html> NewtonList info: <http://lowendmac.com/lists/newton.html> Send list messages to: <mailto:newtonlist@;mail.maclaunch.com> To unsubscribe, email: <mailto:newtonlist-off@;mail.maclaunch.com> For digest mode, email: <mailto:newtonlist-digest@;mail.maclaunch.com> Subscription questions: <mailto:listmom@;lowendmac.com> Archive: <http://www.mail-archive.com/newtonlist%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
