Hi Stefan,Sorry for the

[AJISH ALFRED]

Hi Stefan,

Sorry for the delayed reply.

 

Yes there are 9V rechargable batteries available like this one

http://www.google.co.in/imgres?imgurl=http%3A%2F%2Fecx.images-amazon.com%2Fimages%2FI%2F51JD362JMPL._SY300_.jpg&imgrefurl=http%3A%2F%2Fwww.amazon.com%2FEnergizer-NH22BP-9-Volt-Rechargeable-Battery%2Fdp%2FB00000JGN9&h=300&w=300&tbnid=E6ublYqvhBqHiM%3A&zoom=1&docid=6Ao65KeiDUN5DM&ei=g4fxU9iEF8e4uATuhIKgCQ&tbm=isch&ved=0CCsQMygAMAA&iact=rc&uact=3&dur=2350&page=1&start=0&ndsp=14

 

and I’m using them for a long time, no issues.

 

Your friend could probably be wrong, I would suggest to ask him the reason for that also.

 

Gear motors would be perfect, low speed and high torque