PowerBook Duo battery replacement

[beachycove]

If you were really to try them (they would not fit, BTW, and the voltages are different), the Lithiums would eventually — no, inevitably — catch fire and/or explode, and either burn your house down, or if you were unfortunate enough to be using the machine when it happened, hurt you big time — the gases released from the cells could very well blind you. That's besides the serious toxins breathed in/ handled in cleanup/ lived with for the duration.

I reckon that's a pretty good set of reasons not to tinker with the unknown in this case, even if the result of the tinkering did by some miracle happen one winter Saturday to give you a twelve hour charge. Besides, YOU CAN RECELL A DUO BATTERY with tabbed 4/5 AA NiMh cells, and the charge will sustain the machine for longer than the machine is likely to sustain an interest. That the result will not be everything you want in dreaming the dream is just ... life. Ho hum.

As for a hack/ redesign of the charging circuitry and System software (which seems to be involved — the moves from either Type I to Type II, or from there to Type III batteries, required a System update, precisely so that the benefit of the move would be felt), maybe it can be done. At the moment, however, it might be wiser simply to observe that tabbed NiMh cells themselves are dangerous enough, and not at all like the button cells in the supermarket, as handling them the wrong way can cause steel to glow red-hot within a couple of seconds — if in your pocket, they can literally burn a hole in your leg.

So you really, really do need to be careful if you go there, and I for one would not want to tinker too much with software or anything else where these things are concerned without an engineering background. 'Tis not a ResEdit hack. At most, try your best simply to replicate what is in the machine already.

 

[Mk.558]

These.

How many cells would I need? I would put electrical tape on the ends first time I get them for protection. As far as duration goes, 2.5 hours from a Duo under moderate load is perfectly acceptable. I wouldn't be using it all the time off charger.

 

[beachycove]

Those are the cells to use. 1200 mA is about right for a Duo Type III.

As for quantity, it'll be the number of cells in the photo. Alternatively, open the dead battery to get the layout — you'll have to do so anyway, so why not now?

Some people advise using a utility knife to score the plastics repeatedly, but I have had better luck tapping lightly with a 1" chisel and small hammer, generally one chisel-width at a time and one hammer-blow per spot. I have woodworking experience, so this came as second nature to me. If it sounds complicated, start really light with the hammer and work up to a blow that is hard enough to be effective (you need only crack the glued joint, and that will be audible). Working around the battery at the seam, break the joint so that, at the end, it opens. You don't need to puncture the plastics, or to sever any internal wiring, and you certainly don't want to puncture the old cells.

Take off the sliding endcap first, though. It slides off with a little persuasion.

Like all battery packs, you'll find it a challenge to get back together. You will need clamps/ weights and good glue, and while soldering, to keep things as neat and compact as is humanly possible. E.g., I would advise taking special care with the tabs, perhaps even trimming them to length rather than folding the extra length this way and that. If the battery is too big when it goes back together, you'll likely mess up the action of the trackball clicker, and even a little ball of solder that gets in the way will have a noticeable impact.

That was my experience of it, anyway. BTW, at first, I could get way more than 2.5 hrs with the fabulous 68030 energy saving features of my 270c turned on, and running the thing from a RAM disk, with those cells when first installed. More like 5+ hrs.

A 68LC040 or a 603e will give much poorer performance energy-wise, so if you have a 280c or a 2300c, you won't get that; the 68030 is really a very fine chip for most purposes in a vintage PowerBook.

 

[Bunsen]

1: 4/5A are the original cells, NOT 4/5AA

2: Lithium in Duo packs: NO. Explosion, pain, fire, bad things, not even joking.

3: If you're happy with ~1000mAh, or convinced higher capacities just won't work, why not use AAAs? Far cheaper than 4/5As, being a standard size, and far easier to cram in.

If someone wants to build an external 24V Li pack, with its own charger, controller, protection, etc etc etc, go right ahead, but that's a general purpose battery-pack building exercise best taken up on an electronics forum. And *still* dangerous.

Because of the memory effect in NiMh technology

The memory effect is an issue with NiCDs, not NiMHs.

they will not take a full charge. / you will not get 3 times the battery life / It seems to me that the charging circuitry is geared to lower capacity cells. / I have had several batteries in which this happened.

Type I, II, or III? It seems (from linked articles) that only the Type III has any internal charge controller - the I and II do not. Would it not be more likely that a recelled I or II - a "dumber" battery - would allow higher capacity charging, even though a III does not? The PB must use voltage drop (not time) to measure when a battery is full, and stop charging it - so, why not a larger pack?

the moves from either Type I to Type II, or from there to Type III batteries, required a System update, precisely so that the benefit of the move would be felt

Exactly - to use the onboard controller in the Type IIIs. I assume the updated system retained backwards compatibility with Type I and II?

Kinda odd we're still talking AAs:

4/5A cells are four or more times the price.

As I say, I have not tried it, but I do know for a fact / AA NiMh cells won't fit

... :?: You're looking at 2mm total extra in length (using tabbed cells) - two percent - and a *reduction* in width. That's a smidge under a tenth of an inch over the whole pack - a twentieth at either end. Even if one has to shave down, carve out and/or throw away the end plastics, it seems a large call to say with utter certainty that it can't be done.

4/5 AA NiMh cells are hard to find

No they're not, if you can use ebay search. They're just expensive.

Can the Power Manager be hoodwinked into using / Lithium

No.

no battery strength indication.

Put a LED on the pack.

Using the smaller AAs / the slightly smaller size

The AA is *longer*, but thinner. I don't think repacking will be easier - it may well be harder - but I don't think it will be impossible, either.

regular 4/5 AA {NiMH} cells / Then, just put a diode so the battery can't charge in the duo.

... why???

 

[Bunsen]

In the end, I can see I'm just going to have to try it and see.

 

[theos911]

...why?

That was in reference to using higher capacity cells that the duo may not be able charge internally. This was to avoid a memory effect from the batteries only getting partially charged. However, you pointed out that only NiCD have this issue, not NiMH, making this point no longer relevant.

 

[beachycove]

NiMh batteries, like all batteries, need to fully cycle. NiMh batteries in particular need full recharge and full discharge periodically, which is what all those utilities such as Apple Battery Recondition, Battery Amnesia, and so on were for. They have a memory effect. And I certainly used 4/5AA cells in my Duo recelling. Haven't tried 4/5A so can't say, but regular AA cells will not fit unless you have a tool 8.5" long with a Phoenix tail core and are good at shouting "reductio" with a suitable swish and flick.

 

[Bunsen]

Well, then, if you're convinced that ~1000mAh is enough, then why not just use AAAs at half the price?

 

[beachycove]

Indeed, but we got off on a wild goose chase. However (as said earlier), it would be possible theoretically to use plastic AAA battery holders and do the necessary wiring work on the leads coming from the holders rather than on the cells. This would solve several problems at a stroke: size, mA capacity, and damaged cells due to soldering heat would all no longer be obstacles. Presumably the cells would charge on the same electrical curve as the originals, as the chemistry must be about the same?

Even the last of the Duo (Type III) batteries used NiMh cells with a capacity of (I believe) 1200mA or so, so current NiMh AAAs ought to be able to serve as substitutes. When I last looked a couple of years ago, AAA NiMh cells went up to about 1000mA, and most were slightly lower, but I see on looking today that 1200mA AAA cells are now available.

I once went so far as to buy the battery holders (two sets, for 10 in sets of 3 and 2 cells, with a view to wiring the fuses and such in between on the leads, arranged as in the original pack, and with all thermistors etc. as in the original taped to the side of the cells) but have yet to try it out. Other fish came along to fry.... But perhaps the time has come to go back and see if it can be done.

 

[Trash80toHP_Mini]

Sounds like a hack! :approve:

I'm going to take a 1", or larger, chisel to my (front protruding) BTI Pack, I'll bet there are 6 AAs in there! }

 

[Mk.558]

I will most likely go with AAAs because of capacity match, easier fitting and it is not some marathon battery runner.

 

[naryasece]

EDIT- Anyone know what the 3 middle leads on the battery go to? The - & + are just that, but I'm not sure on the others.

Did anyone figure out what the 3 middle leads do? I got curious myself and set up a little experiment with a Type 1 and Type 3 Battery. The results seem to suggest that the pin closest to the positive terminal is for measuring the temperature of the battery (to keep it from overcharging and catching fire). The pin closest to the negative terminal seems related to getting the power level of the battery. I am guessing that the middle is some sort of common ground for the electronics (Or maybe power?). I'll have to wait to get my hands on a volt meter to see if the Duo is supplying any current to the three middle pins. Or someone else could do it I am a little baffled at why the Duo would not get the voltage of the battery straight from the + and - terminal... If I can find a battery that holds a charge, I'll let you know what pins are optional for running it off battery!

Key:

[ ] open terminal

[x] terminal covered with tape

[-] negative terminal

[+] positive terminal

Type 1

[-] [ ] [ ] [ ] [+]: Attempting to charge, temp 65°

[-] [x] [x] [x] [+] : No battery registered

[-] [ ] [x] [ ] [+]: No battery registered, temp 393° F

[-] [ ] [ ] [x] [+]: Charge: 0%, Temp:

[-] [x] [ ] [ ] [+]: No battery, Temp: 71°F

Type 3

[-] [ ] [ ] [ ] [+]: Attemping to charge, temp 69°

[-] [x] [x] [x] [+] : No battery registered

[-] [ ] [x] [ ] [+]: No battery registered

[-] [ ] [ ] [x] [+]: Charge: 50%, Temp: 393°F

[-] [x] [ ] [ ] [+]: No Battery, Temp: 69°F

 

[Mk.558]

I am under the assumption that the recelling job will only require me to join the respective + and - terminals?

The presence of thermal measurements suggests an internal thermometer. This probably goes in-between cells at the center of the pack. Dunno.

But yeah. I plan on using high cap NiMH AAA cells most likely with 3 of those AAA holders and using hotmelt glue and foam to pack it all back together with...some sort of glue in place of the original sealing adhesive. We'll have to see when the 2300TB arrives.

 

[Mk.558]

I take it I will need 10x 1200mAh cells?

I see 10 batteries here so 10x nominal 1.2v = 12v -ish. The voltage should be the same for both cells regardless of capacity because of chemistry.

I'll get to work on this within a month (scheduled) and will take pictures and all that. Looking for a nice good brand of AAA cells, I don't want junk cells burning up any nice Duos. (Same deal with cheap 123a cells exploding inside flashlights.) I'll stick to name brands like Duracell or Energizer instead of (rebranded?) stuff like this. There's a Batteries+ around here but I'm not sure if they can beat online.

Well, unless I can see how much mAh is present. 850 is too low, if the Duo charger is a timer deal, then it would overcharge it. No elaboration is needed on the possible consequences. 1200mAh seems to be about max and should be close enough to the original 4/5AF size cells in terms of capacity. Amazon should require the batteries listed to supply mAh figures.

Like this. Cool, but....????? Are they old school 600mAh capacity? Who knows?

 

[Mk.558]

New developments!

I went to Batteries+ yesterday looking for some good name brand 1200MAh AAA cells. They didn't have any, only 850 and 1000MAh. But I talked to someone there and they do have the original size cells in the Duo, and here's the info he wrote for me:

"1.2v 4/5 A 1700MAH NiMH $4.29 Each No warrant" (sic)

Cool. That helps, but we've already moved on past putting 1700MAh 4/5 AF cells in a battery which probably had only 1kMAh new. I also notice some sort of resistance welding machine (commonly used in sheet meta fabrication such as cars, metal desks, et cetera) and he said it was as I said (on the order of $2K). I quipped that it was a $2000 machine to solve a 2 cent problem...

To search, and search again: http://support.apple.com/kb/TA32393?viewlocale=en_US

It says the 280c and 2300c use a 1.6Ah battery. 1.6Ah is 1600MAh, that is tiny. If there were ten cells in the pack, does that mean each one was 160MAh? I doubt it. That's probably the rating of a 3v button lithium cell.

Right now I'm doing more research on the PowerBook 520 and 540 to see I can find. I'd love to find out that they are 800MAh cells because good name brand of those are easy to come by in AAAs.

 

[Trash80toHP_Mini]

Great research, if you go again, could you check to see if they have AA Cells for my oversized Duo BatPack from BTI? :?:

When I ship out your 2300cTB, do you want me to crack open one of the two dead Bats for you first?

I've got a very large collection of chisels (wide straight ones and many others) and much woodworking/sign carving experience.

 

[Bunsen]

a $2000 machine to solve a 2 cent problem...

Yes, but thousands of times. Also, as I may have mentioned earlier, a DIY spot welder for battery tabs is not a vastly difficult build.

It says the 280c and 2300c use a 1.6Ah battery. 1.6Ah is 1600MAh, that is tiny. If there were ten cells in the pack, does that mean each one was 160MAh?

No. When you connect cells in series, the voltages add, but the current and capacity do not. A 1600MAh 12V battery is composed of ten 1600MAh 1.2V cells. If you connected them in parallel instead, the opposite happens - voltage stays the same, capacity adds; you would have a 1.2V, 16Ah battery.

Looking for a nice good brand of AAA cells, I don't want junk cells burning up any nice Duos

I've been looking on dealextreme.com for cells. One advantage they have over ebay is that buyers can post reviews of the items they have bought. It's obvious from those reviews that many of the plain-label or off-brand cells greatly overstate their charge capacity - however, there are others who do not. It may be worth your time to do a bit of research there, even if you end up purchasing on ebay.

Trash80: one other thing I noticed on dx was the availability of lithium poly cells with per-cell thermal and over-volt protection, on a tiny round PCB built into the end of each cell.

 

[Mk.558]

When you connect cells in series, the voltages add, but the current and capacity do not. A 1600MAh 12V battery is composed of ten 1600MAh 1.2V cells.

Very well, 10 cells at 1.2v with a 1.6Ah capacity means I should be looking at AAs? Because 1600MAh is beyond AAA capacity by 150%.

I have some AAs that I used in my Uniden 396T that are 2800MAh. The scanner needs it too -- it'll drain alkalines on scan mode in less than 6 hours.

dealextreme.com / buyers can post reviews / many of the plain-label or off-brand cells greatly overstate their charge capacity

I don't trust reviews these days on "review sections" worth a mouse hair. Right around the time I had my 2nd gen iPod touch (figure December of 2010) I used to read and trust the reviews on the Apple Store. About sometime in Feburary '11 it started filling up with glowing 5 star reviews. Any honest review of a (terrible car handling, among other things) Asphalt 6: Adrenaline gets drowned in ~125 highly elated reviews every single day.

lithium poly cells with per-cell thermal and over-volt protection, on a tiny round PCB built into the end of each cell.

The RCR123a batteries I used for my Peak 3W Luxeon flashlight had that too. I don't know the full voltage charge but it had voltage cut off at 2.0v.

Great research, if you go again, could you check to see if they have AA Cells for my oversized Duo BatPack from BTI? :?:
When I ship out your 2300cTB, do you want me to crack open one of the two dead Bats for you first?

What size are they? They did have a chart on the wall that they could "size up" batteries. Also, MAh rating?

I could check again next time I head to that city, they're 50km north of me. No big deal.

Yeah, just crack 'em so I won't have to. The battery is wrapped in $20 bills all around, so if you miss you have to replace

 

[Trash80toHP_Mini]

50 Klicks . . . what's that work out to . . . 14 miles? )

For that crack, I'll crack a bunch of the suckers and send you the two worst! }

AAs are AAs, the Amp/Hr ratings should be higher than the AAAs. I'll crack the elongated BTI unit fourth, it has some corrosion, hopefully it's from the outside and not eating up the DOA goodies inside.

 

[Mk.558]

50 Klicks . . . what's that work out to . . . 14 miles? )

Ugh no, actually.

When you get bored on long drives, start memorizing "relationships" between MPH units and KPH (or km/hr) units on your speedometer. Do it long enough and figures will be automatically converted in your head: 20mph is about 30kph (32 actually), 10mph is 16kph, 40mph is about 60kph, and 50km/hr is about 30mph. (The same figures correspond miles to kilometers too, so when someone from Germany asks you in Los Angeles how far away San Fransisco is, you can say it's about 800km. (because you figured roughly 500 miles, and you knew 50mph = about 80kph from your....studies))

One of my hobbies and personal amusements is giving units to people in 24 hour time and metric units. I like seeing them go ... "WTF is that?"

I got that idea of wrapping the batteries from an instructor I took a class once from. He'd line the perimeter of the bull's eyes with 20$s and if said ...hardened characters missed and hit a $20, they'd have to replace it.

Speaking back on track, I thought we heard earlier AAs are a tight fit. I'm guessing this means I'll have to rig up some arrangement of 20x 800MAh 1.2v NiMH AAA cells. If two batteries are in parallel, then they are combined 1600MAh, and then you take those parallel pairs and hook them up in series to rig up your 12v.

Right? I have doubts about fitting 20 AAAs in there. This is looking harder every step of the way.