--- Samual Acorn <[EMAIL PROTECTED]> wrote: > this may sound odd but i read somewhere that you can > use a cheap > wall-brick with the same output voltage as the > battery a put it in > place of the battery and plug the regular PSU in and > it should power > up (the wall brick will simulate the battery in > order to trick the > portable to boot.... great design eh?)
The Portable always runs off the sealed lead-acid battery. Let it get too low and *pfft!* it's kaput. A modern replacement shouldn't be so sensitive. When plugged in, the charger circuit keeps topping up the battery as the Mac drains it. Apple chose lead-acid because of the longer run time it could have VS the Nickle-Cadmium technology of the time. The drawback was higher weight and the sensitivity to too much discharge. An interesting thing is that in most applications, NiMH cells can directly replace NiCd cells. They're the same voltage but NiMH has a higher energy density so it'll run things longer. A NiCd charger will work just fine on NiMH cells, it just takes longer than a higher rate charger designed for NiMH cells. Some "smart" chargers for NiCd may have problems where they'll shut down before NiMH cells are fully charged. Replacing lead-acid batteries with a bank of NiCd or NiMH cells is a bit of a problem since LA is 2 volts per cell and the others are only 1.2 volts. If the LA being replaced has a total voltage evenly divisible by 1.2, then use that many NiCd or NiMH cells to replace the LA. Be sure the amp-hour or miliamp-hour rating matches or exceeds the original LA battery! It will be total Fandemonium! August (Fri) 4th, (Sat) 5th & (Sun) 6th, 2006 http://www.fandemonium.org __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- Vintage Macs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> Vintage Macs list info: <http://lowendmac.com/lists/vintagemacs.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:vintage.macs@mail.maclaunch.com> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/vintage.macs%40mail.maclaunch.com/> iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com
