I just bought an EV3 and started having battery problems. I am using 6 NiMH 1.5V batteries for my EV3. They lasted for around 10 minutes of work and went flat (that's what the EV3 kept saying but the voltmeter was showing still ~1.5V each).
I ordered 6 rechargeable NiMH batteries. After installing them the brick started and after 2 seconds showed "low battery" status and shut down.
When I measure the voltage on the turned off brick it shows 9.1V and during startup it drops to 8.5V (still reasonably high, eh?). Two seconds later the brick dies and the voltage goes back to 9.1V.
Has anyone had similar problem? What may be causing this?