Best I can tell the controller boards are all custom but the heart of the intelligence is in chips that can be custom or commercial parts. The intelligent battery controller in the Lombard/Pismo battery packs has some Apple programmed values in a serial memory chip that are used by the associated commercial TI bq2040 battery management chip. With an I2C programming interface the serial memory chip 24LC01A contents could in principle be read out, interpreted then reprogrammed for higher capacity cells using the bq2040 datasheet and app note as guides. No cycle counting limit that I know of, but should the battery management board itself detect certain internal board failures it could blow a fuse to protect against shorted series pass transistors. So not all Lombard/Pismo battery packs can be recelled, but I think the majority can unless the series pass transistors are shorted (could happen by ESD or shorting the external terminals).
For other the PowerBooks mentioned, should high resolution photos of the intelligent battery board inside their Li-Ion batteries become available on the Internet, it may be possible to identify the management chip and memory system for each as either a commercial chip or custom proprietary, and infer from that if reprogramming can be done from commercial data alone.
I have not yet had time to examine the trend over time to see if Li-Ion cell current maximums track increased capacity over time as new cell models evolve. In the case of the Lombard/Pismo as an example, since the shunt in the battery manager board is used both to measure mAH as well as to ensure that max current is not approached let alone exceeded (much more important with Li-Ions than with prior technologies!), the shunt can be hacked downwards in value only if safety considerations allow. If, for example, a new candidate cell had 1.3x increased mAH capacity but also tolerated 1.3x increased charge and discharge maximum current values, then the shunt could be adjusted to 1/1.3x the original resistance and the programmed values could remain as original and the new cells used to full capacity (do the math with ratios, NOT percentages!).
The indicated starting mAH would still be reported as that of the original battery, but the scaled shunt would magically cause the PowerBook to appear be drawing less current, and during charge appear to be charging at a slower rate for longer. The reported gas gauge percentage and time remaining numbers would be directly usable without any mental scaling by the PowerBook user.
Each battery model needs to be examined to see if it is a good higher capacity recell candidate, and a given PowerBook may have multiple versions of the battery manager board in the installed base (Lombard/Pismo has at least two and I have only examined one of the two PC layout types). Because of the Li-Ion safety considerations these battery hacks are something best done by engineers and battery recelling organizations with the know-how and necessary equipment.
For other the PowerBooks mentioned, should high resolution photos of the intelligent battery board inside their Li-Ion batteries become available on the Internet, it may be possible to identify the management chip and memory system for each as either a commercial chip or custom proprietary, and infer from that if reprogramming can be done from commercial data alone.
I have not yet had time to examine the trend over time to see if Li-Ion cell current maximums track increased capacity over time as new cell models evolve. In the case of the Lombard/Pismo as an example, since the shunt in the battery manager board is used both to measure mAH as well as to ensure that max current is not approached let alone exceeded (much more important with Li-Ions than with prior technologies!), the shunt can be hacked downwards in value only if safety considerations allow. If, for example, a new candidate cell had 1.3x increased mAH capacity but also tolerated 1.3x increased charge and discharge maximum current values, then the shunt could be adjusted to 1/1.3x the original resistance and the programmed values could remain as original and the new cells used to full capacity (do the math with ratios, NOT percentages!).
The indicated starting mAH would still be reported as that of the original battery, but the scaled shunt would magically cause the PowerBook to appear be drawing less current, and during charge appear to be charging at a slower rate for longer. The reported gas gauge percentage and time remaining numbers would be directly usable without any mental scaling by the PowerBook user.
Each battery model needs to be examined to see if it is a good higher capacity recell candidate, and a given PowerBook may have multiple versions of the battery manager board in the installed base (Lombard/Pismo has at least two and I have only examined one of the two PC layout types). Because of the Li-Ion safety considerations these battery hacks are something best done by engineers and battery recelling organizations with the know-how and necessary equipment.