Over at our sister site https://aibo-repairs.com they can repair all types of battery problems including pub damage.
This is what they have to say about Aibo Battery Repairs:-
Yes you saw that for real, we can and will repair most faults to the pcb contained within the battery of all Aibo models.
One of the biggest killers of Aibo batteries is lack of use, yes this may sound odd but when the cells drop below a certain value a protection circuit kicks in and then this prevents the cells form being charged (as it could overload the charging circuit and/or damage the battery).
This protection circuit is necessary because of the way lithium ion batteries are charged. Their initial charge period is called constant current where the current is allowed to ramp up to the max available by the charging circuit.
After this initial flood charge period the battery will achieve it's potential max voltage (8.4volts for 7.4 volt packs) the charger then switches to constant voltage charging mode where the voltage is held at 8.4 volts (for 7.4 volt packs) and the current is slowly reduced by the battery demanding less and less from the charging circuit.
Eventually this current will drop to the float level which is the value required to keep the pack topped up but not over charge it and cause overheating.
Aibo batteries suffer have this charger design and like most lithium ion battery packs they are of the smart battery design, this has some of the protection circuitry within the battery itself and is part of the problem that Li-ioN smart batteries suffer from as a whole.
Once that pack voltage drops below a certain threshold it's days are numbered.
What this then means is that the voltage inside can only drop as the cells gradually leak voltage unless charged to a very specific storage charge, flaws in the design of the circuit meant that even new unused batteries become useless after prolonged periods of storage.
This then created that catch 22 situation where the battery needed charging but the battery refused to let the system charge it - effectively disabling itself forever (in most cases).
The internal cells then continue to reduce in voltage until they get to a stage that they will never recover, even if they are charged outside of their internal charging circuitry by opening the case. This is the case for the vast majority of original Aibo 110/111/210/220/300 and 7 series batteries and re-celling is the only option.
We can replace the cells in all models of battery and when re-celled the batteries will be of a higher capacity than they were when manufactured as the batteries available today have higher energy densities than were available back then. However this does not necessarily mean your AIbo will run twice as long with a 4ah cell structure as opposed to a 2ah one.
The reason for this is that inside there is a control circuit that knows exactly what the programmed capacity of the battery is and this configuration is protected by a password so just putting bigger capacity batteries in doesn't necessarily mean they will run for longer.
This is however something I have been working on for some time and at some point I hope to be able to replace the existing chip with one of my own programming and then the full benefits of higher capacities will be achieved.
It is worth mentioning that the batteries do run longer but not to their full potential (still longer than standard though).
When it comes to repairing the pcb's within I reserve the right to reject any repairs that are clearly beyond economic repair because a budding diy enthusiast has fried it big time.