Small leaks, such as pinholes in hoses, can be hard to find, so the work might not be done even after a complete evacuation and recharge. The air conditioner might stop working after a few days ...
As well as supplying AC power, the Ugreen PowerRoam 1200 ... 1200 to see how usable and easy it is to recharge. The color LCD on the unit is superb and immediately offers all the necessary stats.