LC_575 Posted October 6, 2010 Report Share Posted October 6, 2010 Yep, makeshift computing. When I first got my LC I immediately assumed buying such a custom battery would be impossible, so I set out to make one. Parts: 3xAAA Battery holder from LED flashlight. 3xAAA batteries. I used alkaline. Connector and Leads from the old battery Electrical tape And this is how it is now: Quote Link to post Share on other sites
protocol7 Posted October 20, 2010 Report Share Posted October 20, 2010 Heh, I just came here to see if anyone had done something similar. I just stumbled across a Japanese page where the guy had done something similar for his 6300. My 5400 had a dead battery when I got it so I bought one from ebay to replace it. Then I left it idle for too long and that one also died. So it's been left dead ever since. I never thought about using 3xAAAs as a replacement. BTW I was told some time ago that it's possible to remove cells from a 9v battery to make it into a 4.5v. I just did a quick google, and found this. Quote Link to post Share on other sites
luddite Posted October 20, 2010 Report Share Posted October 20, 2010 I have 2xAA's in my IIgs, I just bought a battery holder from Radio Shack... The clock's drifted by a few minutes in the last five years (presumably due to the voltage being a tad low), but aside from that it works fine. Quote Link to post Share on other sites
protocol7 Posted October 20, 2010 Report Share Posted October 20, 2010 I've been trying to find a triple-AAA holder that doesn't have the batteries all side-by-side. One on top and two below is what I'd prefer. But no luck in finding one. Maybe picking up a cheap LED flashlight and pulling out the battery carriage is the best option. Though I'd prefer to have both wires connected to the one end like a regular holder. Quote Link to post Share on other sites
johnklos Posted October 20, 2010 Report Share Posted October 20, 2010 Radio Shack sells battery holders which take four batteries. All you need to do is solder a wire across the space of one of the batteries. I've done this on two different motherboards: Quote Link to post Share on other sites
Bunsen Posted October 23, 2010 Report Share Posted October 23, 2010 Or stick in a dummy battery made of dowel, thumbtacks and some wire. Quote Link to post Share on other sites
applefreak Posted October 24, 2010 Report Share Posted October 24, 2010 http://www.batteryspace.com/batteryholder3xaasidebysidebatteryholderwith626awgwireleads-rohscompliant.aspx Quote Link to post Share on other sites
protocol7 Posted October 24, 2010 Report Share Posted October 24, 2010 Yep I think one of those flat triple holders might be better in the long run. The only thing is their footprint might be a bit big. I'll have to have a closer look inside my 5400. At least with these you can replace the batteries without having to lift the holder (assuming you've velcro-ed it down). And there's also no danger of batteries slipping out if the plastic weakens. You can also get enclosed box holders (even some with on/off switches). Quote Link to post Share on other sites
applefreak Posted October 24, 2010 Report Share Posted October 24, 2010 http://www.batteryspace.com/batteryholder3xaaendtoendbatteryholderwith626awgwireleads-rohscompliant.aspx Quote Link to post Share on other sites
applefreak Posted October 24, 2010 Report Share Posted October 24, 2010 all the pram batteries are removed from my computers (no battery = no leak) i have to many computers to put a pram battery in each of them for the fiew who need a battery to start up (macintosh II, IIx, IIfx, ..) and the ones with a bad accessible pram battery location (IIci, IIcx, ..) i use a (or two) mono mini jack (female) at the back of the computer - hole drilled in and attached to a replacable clamp (never in the case of the computer) and a male mono mini jack at a battery holder (different color of the mini jack for different voltage) so i can attach effortless the 'removable pram battery' for the time needed or wished Quote Link to post Share on other sites
register Posted January 15, 2011 Report Share Posted January 15, 2011 the clock's drifted by a few minutes in the last five yearsConsider to use the software "Clock Adjust", a small programme residing in the Control Panels folder. The software permits to set a drift to compensate for. Each time the computer boots, the programme calculates the deviation caused from the clock drift since the last boot process. The programme sets the clock to the correct time and terminates itself. Quote Link to post Share on other sites
techknight Posted January 25, 2011 Report Share Posted January 25, 2011 or if your mac is on the internet, do what I do. use a network time control panel. it sets the clock on bootup. Quote Link to post Share on other sites
Trash80toHP_Mini Posted January 25, 2011 Report Share Posted January 25, 2011 I'vw always used the 4xAA pack from CrapShack, but that 3xAA side by side pack looks GREAT! Quote Link to post Share on other sites
bd1308 Posted January 27, 2011 Report Share Posted January 27, 2011 I've done this on two different motherboards: is that a QuadDoubler I see? Quote Link to post Share on other sites
protocol7 Posted November 14, 2011 Report Share Posted November 14, 2011 Another alternative I've seen online is to use three "button" batteries. Much smaller footprint than the AAA or AAAA batteries. Not sure if the holders are on ebay. I found these on Yahoo Auctions in Japan. Might be a bit more expensive but tidier. Quote Link to post Share on other sites
techknight Posted November 23, 2011 Report Share Posted November 23, 2011 i like the 3 button battery idea better. This is my opinion, but i really really really really really would NOT install the batteries on top the motherboard. if one of them goes, there goes your board. I would use an extended wire, and find somewhere else inside the mac to stick em, encase them or something. Quote Link to post Share on other sites
CelGen Posted November 28, 2011 Report Share Posted November 28, 2011 I recently started soldering CR2032 battery holders into my macs. Seems to work well enough witht he compacts but I ahve not tested with the IIfx yet. Quote Link to post Share on other sites
Dennis Nedry Posted April 14, 2012 Report Share Posted April 14, 2012 The clock's drifted by a few minutes in the last five years (presumably due to the voltage being a tad low), but aside from that it works fine. Because the clock uses a crystal, and crystals resonate based on their physical dimensions/properties, it won't slow down with low voltage. With low enough voltage, there is a point where a crystal stops resonating properly (too weak, just stops, or oscillates weird), but that causes the time to be off wildly. So a low voltage battery shouldn't slow down your clock and a high voltage battery shouldn't speed it up. Quote Link to post Share on other sites
techknight Posted April 14, 2012 Report Share Posted April 14, 2012 well, thats because crystal oscillators drift as well. Thats why rock stable oscillators require a crystal-oven based oscillator, and the most accurate oscillator is a temperature controlled laser pumped rubidium crystal based setup, like what is on board a satellite. This is why the advent of PLL has came along, to account for this in radio circuits, etc... But regular crystals jitter and drift during operation, and regular cheap old crystals are only accurate to roughly 100ppm. Quote Link to post Share on other sites
register Posted June 8, 2012 Report Share Posted June 8, 2012 all the pram batteries are removed from my computers(no battery = no leak) Good point. One should consider to keep the battery on the outside of any machine that is not frequently cared for. Even recent battery makes have a tendency to leak when discharged (nasty corrosive stuff comes out). Simply attach the external battery connector or battery holder to the back panel of the computer (adhesive tape might do). For one machine I cut a piece of plastic into the size of the original PRAM battery and attched a wire to each end, so it serves as a plug to contact the battery holder without a change to the mainboard. In many cases you do not need to drill holes or apply any permanent changes at all. Alternatively you could mount the battery pack into a plastic container that keeps the goo of some leaking batteries safely in place while leaving the outside appearance of your computer untouched. Quote Link to post Share on other sites
onlyonemac Posted June 8, 2012 Report Share Posted June 8, 2012 I once put a voltage regulator (built on a mini breadboard) in my mac. I powered it from a 9V PP3. It was terrible with bits of prestick and sticky tape amid wires running from end to end across the top of the hard drive ! But before that, it was worse. I had a small phone charger-style transformer and I used that to power the regulator and had to leave the case of the mac off ! Quote Link to post Share on other sites
register Posted June 9, 2012 Report Share Posted June 9, 2012 How about using onlyonemac's suggestion and to combine the voltage regulator with the computers own PSU: tap some Volts through the voltage regulator to power the clock chip and add a delay circuit to power up the mainboard only a second later. Get the correct time from a time server and run an AppleScript programme to restore other PRAM based setting. In case of the P475 there are also instructions for an electronic circuit available to provide a soft power on (using the keyboard power button). Quote Link to post Share on other sites
Trash80toHP_Mini Posted June 9, 2012 Report Share Posted June 9, 2012 Getting back to the pics in the OP, I love the idea, but the holder appears to be overkill to this jackleg mechanic, engineer wannabe. ]'> Suggestion for review & feedback: 00) Start with three inexpensive plain old alkaline batteries, IIRC, these have a longer shelf life and longer low current duty cycle than the expensive pink bunny variety . . . 01) use electrical tape to bind them together in the same config . . . 02) use electrical tape to "pressure wrap" the short inter-battery connections and long, color coded, leads in place . . . test . . . 03) wrap leads around pack for strain relief and secure with electrical tape so that the (twisted pair) leads project straight up from the side of the "top" battery as illustrated above . . . test . . . 04) wrap entire assembly in electrical tape to simplify the convoluted shape, maximizing volume/minimizing overall surface area . . . 05) do final testing . . . 06) hold the assembly by the leads and dip it into a can of "liquid rubber" tool grip or "liquid rubber" wire insulation to a depth of about an inch or so up the leads . . . . . . either insulation material should be readily available at your local home improvement store, but the tool grip comes in pretty colors . . . ]'> 07) crimp connect the assembly leads to the connector's leads . . . 08) secure assembly however and wherever you choose with the leads (the assembly's Achilles' heel in terms of leakage) pointing straight up. Doing it this way is probably the least expensive way to do "leak-proof" insulated container battery packs for entire collections. Varying the battery combinations to suit each voltage requirement would be necessary, of course. The packs would be disposable, about as eco-friendly as I can imagine. Just cut 'em open to harvest the wires for re-cycling into another pack at the end of the alkaline cell's useful life. No lead-free or any other kind of solder or soldering required! If one of the cells fail/leak/burst/whatever, the elastic properties and the spare volume inherent in the "containment" design should come into play and save the day. Whatcha think? Quote Link to post Share on other sites
register Posted June 9, 2012 Report Share Posted June 9, 2012 For a leak proof assembly there needs to be a vent that allows gas from the battery to escape (avoid building up pressure in a sealed container), there needs to be some space or a getter inside the container to collect any liquid that may come out of the battery (probably a piece of toilet paper), and also it must be approved that the container is resistant to the ugly battery goo stuff, eating it's way towards precious electronics. Some polypropylene canister or bottle combined with the help of gravity could do, as long as the mounting position is chosen appropriately and the machine is stored in according position. Quote Link to post Share on other sites
onlyonemac Posted June 10, 2012 Report Share Posted June 10, 2012 ...with the computers own PSU: tap some Volts through the voltage regulator to power the clock chip and add a delay circuit to power up the mainboard only a second later. I know I wasn't asking for help but thanks for it anyway . I had thought of hacking the computer's PSU, but I knew that the battery voltage had to be present before the main power could be applied. I didn't think of adding a delay to the main supply. You were thinking of a relay? Having said that, however, I am now thinking of getting a proper PRAM battery , but good luck with your mac anyway. Quote Link to post Share on other sites
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