Have a look at Portable Computing March/86 P. 30; no soldering required: http://www.club100.org/library/libp100.html
Lithium's another story of course... m ----- Original Message ----- From: Josh Malone To: [email protected] Sent: Thursday, June 01, 2017 8:39 AM Subject: Re: [M100] Oh no - think my internal nicad finally given up theghost I've often wanted to build a AA charging circuit into my 102. Or, even an internal lithium battery - since I have a 150mA boost converter board lying around that I never actually did anything with. Except that I'd still need a charging circuit because the board I bought is boost-only and boost+charge boards are readily available now. *sigh* On Thu, Jun 1, 2017 at 2:09 AM, Brian White <[email protected]> wrote: Oh what a great idea using a cap. Not just that. I had already heard of doing that, but the caps discharge time is shorter than a battery, so I didn't really consider it a good answer except for the fun of trying it. But anyone can make themselves a REX now, and REX provides among other things, on-board full ram backups. capacitor + rex = win If you can easily take a snapshot of your entire ram, saved to the REX's flash, then it's no problem if the cap dies in a few days instead of a few weeks. Of course if you're willing to hack even more, sure you could rewire the AAs a little and add a real charging circuit, and have it so the AAs *always* charge the cap, and the wall power recharges the AAs without removing them, just like any modern device. Then you never have to touch the insides again, just the battery cover, and even that only every 5 years. But with the ability to make backups right on-board, you can get away with a simple in-place cap swap with no other mods. Not having to worry about leakers in a few years, or overcharging, would be nice. -- bkw On May 31, 2017 10:08 PM, "Josh Malone" <[email protected]> wrote: On Wed, May 31, 2017 at 2:29 PM, John Gardner <[email protected]> wrote: That's what it is in the 8201a too, IIRC. So if the rail is 5V the NiCD is seeing a charge current of ~ 3 mA - Which may explain some of the resurrections of dormant laptops after prolonged noodling around with them... Thanks for sharing! ... On 5/31/17, Josh Malone <[email protected]> wrote: > The m100 techref schematic shows 1.6k (I think - it's an awful photocopy I > found online) > > https://dl.google.com/dl/androidjumper/mtp/502266/androidfiletransfer.dmg D'oh! I completely posted the wrong link - meant to link to the m100 techref. Sorry In any case, 3mA is more-or-less C/20, so yeah, kindof a slow charge.
