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/androidfil >>> etransfer.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. >> >
