Thread
Generic PRAM batteries
Since I needed a bunch I decided to go with a bulk purchase and managed to find 10 packs for $28 shipped. Nearly every beige Powermac and Quadra I have thinks it's 1956. 8-o
Wow! That's a good price! 
Do you leave all of your systems setup and plugged in? If not, I wouldn't bother leaving a battery in them anyway. I've lost several computers to exploded batteries that destroyed the motherboards. Needless to say, I pull all the batteries from my computers in storage... even the ones where the battery is hard to get to.
Do you leave all of your systems setup and plugged in? If not, I wouldn't bother leaving a battery in them anyway. I've lost several computers to exploded batteries that destroyed the motherboards. Needless to say, I pull all the batteries from my computers in storage... even the ones where the battery is hard to get to.
Where did you get the 10 pack from?
I leave batteries in the units I use once in a while, but anything put into long term storage has the battery removed.
I leave batteries in the units I use once in a while, but anything put into long term storage has the battery removed.
I've been replacing the 1/2 AA batteries with a two AA or two AAA battery holder held on with either double sided foam tape or hard locking tape for ages, like so:
There are two good things about doing it this way. One is that batteries are much easier to find, and the other is that you have your choice of the kind of batteries. The ones in the above picture have been replaced with lithium AAAs and should be good for ten or more years.
There are two good things about doing it this way. One is that batteries are much easier to find, and the other is that you have your choice of the kind of batteries. The ones in the above picture have been replaced with lithium AAAs and should be good for ten or more years.
I wanted to do something like that but don't know how. Would I have to solder the wires to the existing battery socket? If I could attach the wires without soldering, that would be better. It would help because I use rechargeable AA's so I wouldn't have to buy batteries very often.
Yes, all the Macs still have the batteries on the boards but none of them looks like they've leaked yet. Hopefully once they are changed the machines will be in somewhat active use.
I got them from ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200444749458&ssPageName=STRK:MEWNX:IT
You can get larger quantites from other sellers but I don't think many of us really needs 50, 100, or 1000 batteries lying around. This 10 pack price seemed reasonable without any of the batteries going to waste.
Yes, all the Macs still have the batteries on the boards but none of them looks like they've leaked yet. Hopefully once they are changed the machines will be in somewhat active use.
I got them from ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200444749458&ssPageName=STRK:MEWNX:IT
You can get larger quantites from other sellers but I don't think many of us really needs 50, 100, or 1000 batteries lying around. This 10 pack price seemed reasonable without any of the batteries going to waste.
I have used those kinds of batteries and holders on old PCs before, they work fine but all eventually leak. So I retrofitted quite a few machines to use coin type batteries (PCs) and just use normal batteries for macs when I find them cheap enough.
I got ~15 coin cell holders going to waste if anyone wants me to drop one in the post
I purchased a couple dozen from Indonesia or somewhere for next to nothing, so I am good.
If the batteries leak, then they're either being charged or you're using cheap batteries. Batteries should never leak when they die.
Yes, it'd be more permanent to solder them. Soldering a single wire at a time is pretty easy. It's much easier than soldering components.
You've got the wrong idea about rechargeable batteries. They don't hold a charge long even when there's no draw on them, and the idea of taking them out every couple of months to charge them defeats the whole idea of maintaining the power when the system is off in the first place.
In reality, the shelf life of AA or AAA batteries is approximately equivalent to the amount of time they'd last on a motherboard because the draw is so low as to be almost insignificant.
Sorry, I've seen it too many times in Mac's left in storage. This is from my most recent conquest. It had been left in storage for over 10 years. I've lost two 6100's that had much more damage than this and were in storage for only a couple years. I've seen batteries start leaking in dozens of other Mac's. It's not just a random occurrence - it's a hazard.
Oh! I thought you were talking about AA or AAA batteries leaking when used on motherboards. I've had one AAA battery leak most likely due to the fact that the machine was stored in a place that was above 120 degrees Fahrenheit for a while. But because it leaked in the battery holder, I just swapped out the battery holder and the motherboard was untouched.
Yes, this is part of the reason I use AA and AAA batteries.
Yes, this is part of the reason I use AA and AAA batteries.
Ah! Ok...
I've never used AAA batteries in my Macs. As you can tell, I'm really paranoid about batteries. I hate opening up the cases to find the mobo destroyed... :'(
I've never used AAA batteries in my Macs. As you can tell, I'm really paranoid about batteries. I hate opening up the cases to find the mobo destroyed... :'(
Pay more for lithium AA or AAA, and you'll never have to worry about leaking.
For me it really doesn't matter because my machines are mainly display pieces that only get checked to see if they are working every couple years. 76 computers takes a while to go through and I certainly don't have the room to set them all up. Though, I am remodeling my computer room so maybe I can have up to 10 of my vinatge machines setup. Everything else will be on display, and possibly rotated in to the working setup occasionally.
Damn! Seventy six computers?
You and I are at opposite ends of the spectrum, I believe. I have what I thought was a decent amount of machines, but I try to get them to justify their existence by doing useful things (NAT, DNS, email, static web, offsite backup, et cetera). For me, the idea of a machine not coming back up when it's shut down (if it's ever shut down when it's in New York and I'm in California is not a a nice idea to contemplate.
For you, you might consider something like a capacitor and a couple of diodes (to both make sure the capacitor doesn't discharge from the 5 volt rail and to drop the voltage) so that you'd only have to turn on the machine for a few moments, then reboot to have a working machine.
You and I are at opposite ends of the spectrum, I believe. I have what I thought was a decent amount of machines, but I try to get them to justify their existence by doing useful things (NAT, DNS, email, static web, offsite backup, et cetera). For me, the idea of a machine not coming back up when it's shut down (if it's ever shut down when it's in New York and I'm in California is not a a nice idea to contemplate.
For you, you might consider something like a capacitor and a couple of diodes (to both make sure the capacitor doesn't discharge from the 5 volt rail and to drop the voltage) so that you'd only have to turn on the machine for a few moments, then reboot to have a working machine.
76 I believe is accurate. It's easy to lose track. The link to my machine list in the 68kmla wiki is in my sig.
The machines I have setup, 6 for me and 2 for my wife, are all setup for specific reasons. I'd like to at least setup another 5 once my remodel is done. Most of my collection are "rescues" that were going to be thrown out, or ones that I received as payment for computer work I've done. I've only bought (either new or used) maybe 20 of them.
Interesting suggestion about the capacitor and diodes... I'll have to give that some thought.
The machines I have setup, 6 for me and 2 for my wife, are all setup for specific reasons. I'd like to at least setup another 5 once my remodel is done. Most of my collection are "rescues" that were going to be thrown out, or ones that I received as payment for computer work I've done. I've only bought (either new or used) maybe 20 of them.
Interesting suggestion about the capacitor and diodes... I'll have to give that some thought.
Wow... If I were to count, I have less than twenty, most doing something useful. I'm still trying to find a useful place to host two m68k Macs - one is a Quadra 610 for which I need a NuBus adapter so I can have two ethernets so it can do NAT...76 I believe is accurate. It's easy to lose track. The link to my machine list in the 68kmla wiki is in my sig.
The machines I have setup, 6 for me and 2 for my wife, are all setup for specific reasons. I'd like to at least setup another 5 once my remodel is done. Most of my collection are "rescues" that were going to be thrown out, or ones that I received as payment for computer work I've done. I've only bought (either new or used) maybe 20 of them.
Thank you. I like to keep old machines running, although I'm not super-sentimental about keeping them completely original. Many of mine have added oscillators, m68040s with permanently attached heat sinks, QuadDoublers, batteries, et cetera. But seventy six... Damn! That'd be around $450 just for the lithium batteries if you put two in each machine!
Macs and PC's added together I probably have about 50 but most of the PC's are for future parts salvage. There's only a few that I intend to keep intact like my Dell GX 1's. I'm retaining them because I really like the styling. They are very reminiscent of the beige desktop Powermac cases and sturdily built to place large screens on top, though only the PSU tips up for access. They have three RAM slots like the beige G3 desktop with the same official RAM capacity though the Dell uses PC100 RAM instead of PC66, ATi Rage graphics like the G3, and I really like the look of the case. (did I mention that already?) 
Nice! It's good to have projects.
I've got several I'd like to setup... Quadra 950, IIsi, Q605, MacTV, DuoDock w/ Duo 2300c, one of my Sun machines, one of my Atari's. I already have an SE/30, Beige G3, G5, MacBook Pro, Apple IIe, and a home built PC in my MAME cabinet setup.
It seems like most of my projects involve cataloging, testing, and repairing my old systems
I definitely like to keep them running, but I lean toward keeping them original. I will switch cards, HD's, RAM, use parts from one to repair another, and the occasional processor upgrade, but nothing too drastic.
Yeah, the cost of keeping batteries in these old systems is a prohibitive factor, as well. Most of the batteries I have were pulled from my collection. If they register 3.6v, I keep them for when I need to plug them into a system.
I dont have a problem with buying batteries online, but only from certain trusted places, random google hits and ebay are just too loaded with half battery half led weight for me to gamble my almost non-existent toy budget
I got a brand new SAFT 3.6V lithium online for a good price. My multimeter shows its perfectly good.
The only thing I worry about online is giving out my credit card info. If some non descript site takes paypal then I might order from them, but I don't enter my credit card info to some fly by night website.
In the case of machines that take a 1/2AA 3.6V battery, you can substitute the battery for a piece of wooden dowel the same size, with a thumbtack pushed into each end. Strip the wire ends coming from your new battery holder and twist them securely around the centre pin of each thumbtack, and mark your dowel for + and - . If you purchase a new battery holder with leads already attached, then there's no soldering at that end either.
One good thing about using rechargeable AAs is they are exactly 1.2V when fully charged, so three = 3.6V. Alkaline AAs are 1.5V, so x 3 = 4.5V. I have no idea whether this would be a problem compared to the original 3.6V battery.
In the case of older Macs with the square 4.5V battery that plugs into a motherboard jumper, cut the lead and plug off the old battery and attach the wires to your new battery holder. You can either solder the wires or twist and tape/heatshrink. Then simply plug back into the motherboard jumper.
Of course a properly soldered joint between wires/thumbtacks etc is going to be more secure. In either case, there's no need to risk soldering anything directly to the motherboard.
I use the AA and AAA lithium which are usually around 1.55 volts when new.
Do you use two (3.1V) or three (4.65V) to replace a 3.6V PRAM battery? Or are you referring to replacing the 4.5V square PRAM batteries as pictured above?
Here is a way to get these 3.6V 1/2 AA PRAM batteries at a better price; 10 for $26 shipped in the US ($28 worldwide). I have purchased from this lot recently and I can attest to their quality.
Mike Richardson seems to only sell this package to ppcmla folks. Perhaps a PPCMLA dude could get Mike Richardson to sell this package to 68kmla folks as well?
Membership in the PPCMLA is free and easy. Anyone can sign up. Their forum also boasts a number of mysterious and liberating features which seem to be absent here.
Two batteries. 3 (or 3.1) volts is plenty for the backup. For the 4.5 volt square batteries, I use three batteries like so:
For the motherboard which take the little rechargeable batteries (like Amigas), I use three batteries with a diode.