PowerBook Duo battery replacement

[Mk.558]

So you think a staggered array of AAAs will fit?

I measured a stack of staggered and they appear to total about 3/4", or close to 17mm.

I'd probably use glue to hold them together -- I'm banking there's not enough room for a nice battery holder array.

 

[techknight]

One thing I have never studied deeply, was "smart" charging circuitry. It wouldn't be hard to make a new PCB with new circuitry for charging batteries, the problem being is not too sure how charging systems work. Lets say I have a 7.2v battery pack, and i hit the pack with 8v or maybe 9v to charge it, Wouldn't it be 9V at the terminals of the batteries?

Almost need some sort of resistance between the pack and charging voltage to be able to measure the voltage drop across the resistor for current consumption, and then the voltage point at the batteries itself. I dunno about duo, but i know on the old 190/5300s they just had a simple serial ROM that told the machine the battery was installed and its type/capacity.

 

[Trash80toHP_Mini]

I need to get this circuit board documented and figure out if it can be implemented, preferably in the Duo, in the 2 Battery Charger Pack at worst, or in both.

I'm hoping osfjd will chime in, he's a power supply kinda EE Boffin. If he doesn't, I'll be PMin' him! :approve:

 

[techknight]

I am an AVR fan myself, as thats the MCU I am most familiar with.

Here is a battery charger sheet that explains the different battery types, and how they are charged:

http://www.atmel.com/dyn/resources/prod_documents/doc1659.pdf

 

[techknight]

I just wanted to toss in some more tidbits:

Quote from a site:

The Ultimate Charger

Sometimes the most important issue is the lifetime of the batteries or the total lifetime cost of the system. In this case PowerStream is in a good position to offer the ultimate charger because of our wide experience in microprocessor controlled battery chargers and power supplies. Specs for the ultimate charger are:

1. Soft start. If the temperature is above 40 degrees C or below zero degrees C start with a C/10 charge. If the discharged battery voltage is less than 1.0 Volts/cell start with a C/10 charge. If the discharged battery voltage is above 1.29 V/cell start with a C/10 charge.

2. Option: if the discharged battery voltage is above 1.0 Volts/cell, discharge the battery to 1.0 V/cell then proceed to rapid charge.

3. Rapid charge at 1 C until the temperature reaches 45 degrees C, or the dT/dt indicates full charge.

4. After terminating the fast charge, slow charge at C/10 for 4 hours to ensure a full charge.

5. If the voltage climbs to 1.78 V/cell without otherwise terminating, terminate.

6. If the time on fast charge exceeds 1.5 hours without otherwise terminating, terminate the fast charge.

7. If the battery never reaches a condition where the fast charge starts time out the slow charge after 15 hours.

8. Fuel gauge, communication to the device being powered, LED indicators all possible.

Custom design and manufacture of state-of-the-art battery chargers, UPS, and power supplies for OEMs in a hurry!

From site:

http://www.powerstream.com/NiMH.htm

Good Read. If i were to ASSUME, the PB probably uses the dT/dt technique with 1C charge, besides, the current/voltage sensor used in a loop to keep the current level at 1C is used as the fuel gauge as well. But in order for this charging scheme to work, and to be able to calculate 1C, or 10C, or whatever charge mechanism you use, you MUST know the initial capacity. So, this is given by the battery's ROM, or by some other means. As mentioned, the -dV/dt method is better because it leaves the capacity out of the equasion, BUT it destroys NiMH because its more sensitive to this (less drop across threshold than NiCd). So its for NiCd and is probably used in the PB1XX series.

 

[Bunsen]

technight: that battery charger PDF is a great resource. Thanks for posting that - it's filed away for later reference for many, non-Mac related projects

I have a little test I've brewed up to settle the capacity argument once and for all. If and when blah blah etc, I'll try it myself, but if anyone else feels like having a go, I'll document my thoughts here:

1. Dismantle a Duo battery pack
   
2. Buy ten matching, reliable high capacity AAs
   
3. Mount them in standard AA holders.
   
4. Add the little thinggum from inside the battery pack in between the equivalent pair of cells to its original position inside the Duo battery.
   
5. Wire from the AA holders to the contacts inside the gutted Duo battery.
   
6. Use the Duo (or the Lind charger) to charge them
   
7. Test them attached to the Duo

Above provided for entertainment porpoises only. BunsenLabs accepts no responsibility for personal injury, property damage, or the heat death of the universe.

NB, if one plans to later attempt to fit the cells inside a Duo battpack, one would of course need the solder-tab version, not the button-ended ones. If the tests fail, one still has a portable 12V power pack, or several smaller ones, for other uses.

 

[Mk.558]

Keep in mind though, according to my calculations (insert crazy scientist form here) AAs won't work inside the actual battery...

• 4/5 AF dimensions: 17x40mm (Battery Station says 16.5x42)

• Fullsize A dimensions: 17x50mm (Wiki) (Battery station says 16.5x48)

• 4/5 AA dimensions: 14.5x43mm

• Fullsize AA dimensions: 14.5x50.5mm (must be the button version)

• Tabbed flat terminal AA: 14.2x50mm

• AAA: 11x45 flat terminal, batterystation.com says 10x43.7.

I'd love to tap into 123a batteries but they're made only in alkaline ($$$$$) and Lithiums (reasonable).

Above provided for entertainment porpoises only. BunsenLabs accepts no responsibility for personal injury, property damage, or the heat death of the universe.

entertainment porpoises only.

I'm quite interested in your aquamarine battery pursuits. :approve:

I could jump into this foray right away but I'm awaiting a certain shipment from the Bermuda Triangle. Once you do get your setup rigged up, see if you can somehow measure the remaining capacity to see if the batteries did get indeed filled up completely. Given that...

The thing is, the original NiMh cells used in 1993-4 were typically rated around 900mA. The PowerBook will not work well with 2000 or 2500mA cells, anyway, as it seems not to know quite how to charge them. We have this behaviour in 540c recelling attempts too.

and considering that...

Higher capacity cells will take a good charge, but as far as I can determine, they will not take a full charge. Thus you will typically only get the battery life (2.5 hrs or whatever) originally projected for a Duo battery from a recelled unit; you will not get 3 times the battery life originally projected (7.5 hrs. or whatever). It seems to me that the charging circuitry is geared to lower capacity cells. Because of the memory effect in NiMh technology, this then has a degrading impact on the cells. I have had several batteries in which this happened.

 

[Trash80toHP_Mini]

Well, so far I've identified two different versions of the standard, Type I Duo Battery pack, neither appear to have special markings to designate them as Type II or Type III. I'm sending both of those along with a Two Battery Charger unit for Mk.558 to pick apart, document here, and to determine if the charger's the place to put a clone of the High Capacity BTI Pack's PCB instead of inside the Duo.

My charger unit was freed up for this purpose when jruschme gifted me with his, thanks again, buddy! [] ]'>

I've also found a standard BTI Battery Pack amongst the sheep to crack open for comparison with the two standard Apple Pack revs along with the High Capacity BTI Pack.

My workbench is now clear for me to get crackin' on some more hackin' projects again! :approve:

 

[Mk.558]

New developments:

AAs won't work. You can only fit 7 of them in. That'd be fine if all we were looking for was 8.4v but that is not the case.

AAAs also won't work. You can't fit 20 of them in, not easily at least. The most I believe could fit is 15, and double-stacking is essentially ruled out because there's not enough height in the case.

For reference, the pack is about 13mm shorter in length than a 12" iBook G3 A1005 battery, and about the same height and width. (Except the iBook one is 4400mAh instead of 1600mAh)

The solution? 2/3 As. Not 2/3AAs -- those are about 700mAh.

Like these. Capacity correct: Yes. Size: Yes. Solution: Quite likely.

You'll still need solder tabs, though. You'll also need to properly re-wire the thing back together. Probably start by making a map of the circuit and battery polarities. Since I have two batteries, I could probably recell one for myself and sell the other one for cost + shipping (if there is interest). Not like I'll be taking notes with that dream keyboard all others aspire to be rough, coarse keyboard. It's just a hobby laptop that is retro for the fun of being retro.

 

[Trash80toHP_Mini]

:lol: I think you're the first to complain of a Duo KBD being rough and course! ALL the early revs are like mushy, spongeboards, that's the real problem. You've got a late Rev KBD that just needs to be used a bit to get it broken back in shape . . .

. . . kind of like oiling up and working your ball glove after taking a few too many seasons off! )

 

[Bunsen]

It's worth saving the removed 4/5A cells and testing them individually, if you can. One or two borked cells in a pack can render the whole pack useless, while the other cells may still have some life left in them.

 

[Mk.558]

It's worth saving the removed 4/5A cells and testing them individually, if you can.

I don't have a variable voltage variable current power supply to do this. The current will have to be done manually along with a current/time slope to cap them off.

Still, I have little faith in the ability of a couple of cells to withstand 16 years of abuse.

 

[Trash80toHP_Mini]

Where is Waldo?

Waldo being the code-name for a "dBook" hack featuring a non-inter-changeable, internal, WORKING, inexpensive AA battery pack . . .

. . . that'll charge just fine from the Duo's MoBo BatPack rails . . .

. . . once they're hijacked to the HDD Bay, that is. }

. . . oh! Don't forget the silent aspect of the Waldo™ hack. Yes it fits . . .

. . . and it can be upgraded to an SD/Chiplet as 1.8" IDE HDD! :approve:

edit: forgot to mention the provision for a Disk Access LED hack on this particular board

Lets not forget that the Battery Pack will hold a 2.5" SCSI SSD and it shouldn't be at all difficult to hack a connector to make it removable!

 

[Mk.558]

Now that ^ would be a useful hack.

We should give these ideas to Apple, and they should make the Duo just for us all over again. Better this time: but still a 100MHz 603e CPU. This time they do it right: Built-in WiFi and Ethernet (we don't need no stinking 14.4Kbps modem), lithium ion battery that slides in and out like a CF card, CF device for a hard drive, ...and of course it will have a trackball with optical tracking instead of wheels.

Actually, given the way the Raspberry Pi was pushing 1080p video, I'm not quite sure there are such things as excuses not to do it...I mean that thing has dual USB, Ethernet, HDMI, sound out, and a cheap price tag. That has a recipe for a SuperDuoHack.

As far as the batteries go, I just have to order some 2/3rds A batteries and a CMOS battery, or tear apart the one I have and see if it's possible to not spend 40$ on some coin cell battery with tabs soldered on with protective wrapping and some wires.

 

[Trash80toHP_Mini]

I've got two more configurations to document:

1) Ten AA Cells will fit into the Battery Compartment just fine

___Micro-ENSC in right side of HDD Bay w/SCSI Cable + Adapter from internal 2300c SCSI Connector

___Same HDD replacement scheme with Micro PCI-e IDE SSD in between TrackBall and ENSC

___De-soldered RJ-45 replaced with wires leading to same mounted to the Power Board in the MoDem Bay

2) Seventeen AAA Cells in between TrackBall and Micro-ENSC, the other three AAAs in the excess Modem Bay Cubic

___Micro PCI-e IDE SSD will probably fit on top of the hacked Micro-ENSC [] ]'>

. . . in either hack, four holes drilled in the right edge top plate will expose the four activity LEDs of the NIC! :approve:

BTW, Hacked AA Battery holders will alleviate the need for tabs, spot welding/soldering and make re-celling a snap!

pics to follow! }

p.s. I've got the skeleton of another 2300cTB up and running! [] ]'>

p.p.s. Got Torx? :?:

 

[switch998]

Those stock cells look extremely close to the Sanyo NiMH batteries used for the newton rechargable battery packs. Wish I had a link to where I bought my cells from, but I lost the link a long time ago.

 

[Mk.558]

Has anybody made headway on this?

I personally haven't, but I'd like to start when the Hobby Fund has been replenished, likely with the timing of a certain government tax time...(assuming they don't give us all IOUs like last year (or was it 2 years ago?)).

I was checking on Amazon if they had any single 1600MAh 2/3A cells, and found this. I thought "Hey, I could just put two of those packs together (get the dimensions first) in series, and there's my 12v at 1600MAh each!"

Worst case scenario, they're still 1600MAh 2/3A cells, 5 a pack, and you'll know they have solder tabs on them, so....yeah. Just looking at the way the factory made the Duo cells with cryptic wiring paths and nonexistent polarities makes me cringe a bit.

 

[Trash80toHP_Mini]

Those packs look VERY interesting! :b&w:

 

[Bunsen]

(get the dimensions first)

Hmm well, going from the dimensions of bare 2/3A cells from your previous link:

Height : 28mm (1.10")

Diameter : 17mm (0.67")

Each pack has to be a minimum of:

Width: 17mm x 2 cells = 34mm x 2 packs = 68mm

Height: 17mm

Length: 28mm + 28mm + 17mm = 73mm

From my previous adding-up of the Duo pack as it came from the factory:

Existing width: 2 x 17mm + 49mm = 83mmExisting length: 2 x 49mm = 98mm

No problem You've got a full 15-25mm to play with in either direction.

 

[Mk.558]

Inside dimension (widest): 79.5mm

Inside dimension (width inside pocket for catch mechanism): 64mm

Inside dimension (length): 103mm

Plenty of room. The are some ribs inside that could either be worked around or sanded down. Either way the smaller size gives us some room, the 1.6Ah matches the original, nobody has to some fancy rewiring of a circuit that we know little about since there are no + or - marks on the originals, and I think that is what I will do. I'll probably stuff the insides with foam and glue the packs down on the edges to the base so a little heat and the packs come back out easily. Probably will superglue the battery pack itself together.