My fuses arrived a few days ago, i just put one of them into the Z, and now it works fine, charges the battery.
Now there is only one thing left to do: buy a better charger - this one is only 500mA, and the Voltage is really crazy one.
I've got an adapter that can produce 3, 4.5, 6 V outputs, but at 3 V i can measure 5.5 V. With this voltage, the Z only charges the battery to 50%. With the next step, at 4.5 V i can measure 7 V, and if i put this voltage in the Z, the charging led blinks.
Anyone idea?