Over the past few days I’ve seen stories regarding the LEGO Education EV3 Battery Pack circulating on the various forums and FB groups. Yesterday LEGO Education released a statement to customers and partners who are affected by this issue, confirming the problem. I’ve put a small excerpt of the statement below. You can download the full text here (zip file with two PDFs): [LINK].
Dear Customer ,
The LEGO Group prides itself in delivering high quality products and regrets to inform customers of an issue related to the LEGO® MINDSTORMS® Education EV3 rechargeable battery .
LEGO Education has identified a circuit error in the LEGO MINDSTORMS Education EV3 rechargeable battery .
The error does not in any way relate to , or impact the EV3 programmable brick or the charger/transformer. The majority of the batteries that have been distributed do not have this error, but every battery in stock is now being retested to ensure it charges properly before shipping to customers, and new supplies are being sourced.
So in short, the issue is with the pack, not the brick. So for now, just use AA batteries until you can have the pack replaced.
FYI, I have had a problem with totally 3 new battery pack on my new set of 12.
After I have read the problem above, I have plugged the remainder of my new rechargeable battery and open my brick right away and it is ok.
Do not wait fully charged battery to open the brick.
Suzan
I looked at the Lego Battery Pack at 60 quid plus charger at 20 quid and found this very expensive for a 2200mah 7.2 lipo battery 🙁
I did try Nimh Battery but at a nominal voltage of 1.2v compared to a normal disposal battery at 1.5v they did work.
The best solution that I have found is NiZn batteries that have a nominal voltage of 1.6v.
Hobbyking NiZn Battery