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.

This article about Aibo Head and Leg Tremors is taken from our sister site at https://aibo-repairs.com

Ok so elsewhere I have covered the other "Syndromes" of the ill-fated Aibo family (well most the ERS-210 up to now) and yet another common problem persists within the Aibo gene pool.

This is the well know (and far reaching) leg and or head tremors.  The compact nature of the Aibo family required many many engineering challenges to be overcome without creating a unit that cost $20,000 and just wouldn't sell, so best efforts were used in the name of an affordable product (well sort of)

and a compact unit.  One of these best efforts was to use resistive motor location instead of optical location so a small variable resister is used which changes it's output value based upon where the motor (and it's attached limb) is positioned.  This was an elegant design and was well used within the radio controlled model servo industry so it was tried and tested.  The significant difference between these two methods of use was that in most cases a radio controlled model would be luck to last 20 weeks let alone 20 years and as such inherent wear was bound to come into play.  This wear exhibits itself as tremors in the Aibo's limbs and can be quite distressing to watch sometimes and is caused by dirt entering the variable resistor component and altering the accuracy of the output it generates and sometimes it is just worn out.  This then leaves Aibos servo motors controlling it's limbs unable to detect their exact position and causes the tremors as the motors continually try to correct their position over and over without success.

The resolution for this is first to determine of it's just dirt ingress or if the part is actually worn out and once this has been determined the corrective method is applied with either the unit being cleaned or replaced.  

Most AIbo's exhibiting tremors only do so after many years of use and this syndrome is not normally associated with units that have been shelf queens or are new old stock.

Once repaired the units function normally and as yet none of my own pack that have received this repair have ever re exhibited any tremors (except when faced with my Dalmatian).