Aibo Battery Repairs

Yes you saw that for real, I 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 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.

Lithium Ion cells suffer what is known as sagging - the drain on the pack pulls the voltage down - Aibo sees this and will switch off towards the end of the pack charge - often you can switch them back on and they will run another 20 minutes or so.



In tests (and reported by our customers) run times on 210 batteries that we have re celled have run for well over 2 hours and as long as 3 hours in active use.

When it comes to repairing the pcb's within we reserve the right to reject any repairs that are clearly beyond economic repair because a budding diy enthusiast has fried it big time.


As seen in the image below - storage for extended periods can cause the cells within to leak and corrode.

Leaky Sony Aibo ERA-201B



We use the same spot welding techniques used by the original pack manufacturer and maintain all the correct insulation methods and cable and cell placement - we don't cut any corners and all safety features remain intact.

The pack control circuitry gets reprogrammed to allow it to correctly record the higher capacity of the new cells - all charge counters are also reset.

 After re cell / repair has been completed your batteries will look like the image below (ERA201B - ERS210/220 Battery) inside :-


Sony Aibo ERA-201B ERS-210/220 Battery 



All our repaired / re celled batteries undergo rigorous testing prior to being shipped using our state of the art DC load testing kit as shown below:-


Sony Aibo Battery Testing Equipment