Help - LBA10 balancer

Don't know is this is the right place, but I'm pulling out my hair concerning my 2 LBA10 balancers.

I'm trying to use them in 'Connection'-mode since I wan't to charge my lipo's and balance them at the same time. So according to the manual I think this is the correct mode.

Anyway, I follow the instructions :
- connect the balancer to the lipo comptatible charger (in my case a Robitronic Overloader set to lipo 2s 7.4v and 6000mah for my Maxamps)
- connect the correct balancing cable to the balancer (2s)
- connect the balancing cable to the battery
- connect within 12sec the batterly leads to the LBA.
- press reset button to go into 'Connection' mode.
- press 'charge' on the charger.

The charger starts to charge (I can see it pumping mah into my lipo) and the balancer starts flickering one of the leds of the lipo cells. However after some minutes the balancer shuts down and the charger gives the message 'battery disconnected' and thus cannot charge.

What I'm I doing wrong ?

Thanks for your answers.