Cant see how it would do any harm, but obviously if you are sticking wires straight onto battery posts then they are not fused properly so shorting the wires or getting a fault may not end well for your pump or the wire going to the pump.
Personally I would get a cig lighter plug and attach it to the pump wire so you can plug in to cig socket, there only a couple quid and easy fit but if you need to blow it up right now I would jump it straight on to get you out the proverbial