You need to explain this better, it makes no sense as it is. edit: no way to know exactly. Voltage alone tells you nothing. But the power used (in watts) could be a guide, if you have that number, in watts. 1400 mA-hour is a measure of the charge stored in the battery, so that is no help, as you need a time number to convert that to mA, which, with the voltage, can give you power in watts. My experience is that hand held vacuum cleaners are all very feeble.
