Recognise this type of connection?

[Driver101]

The charger is from a JBL Flip bluetooth speaker first edition.

I use it for my work and can't always get mains power after the battery has gone flat.

I see the input is 12v @1.5 amps.

Is there a connection with that end that leads to a USB connection? Secondly would a battery pack with a 5v and either 1.2amp or 2 amp output be enough to power it?

[FlossyThePig]

I would suggest the simple answer is no!
Your device needs 12 volts and you are looking at 5volts in both of your options.

[Driver101]

Wouldn't 5v just be enough to keep it powered or extend the battery life of the speaker for a reasonable period?

When putting in 12v the speaker charges very quickly even when on.

[twister]

Almost certainly not, because whatever circuitry is sat behind the power socket on the speaker will have been designed around the presumption that it'd be fed with 12v, so feeding it with anything lower than this (by more than a few %, and 5v certainly falls into that category) would likely result in nothing whatsoever happening.

[miniman]

http://www.ebay.co.uk/itm/5W-USB-DC-5V-to-12V-Step...

This will step 5v up to 12v, but obviously it won't be able to supply the same power. It might trickle charge it though.

[lbc]

If you step the voltage up from 5 volts you will lose the current, so may only have enough power to operate a torch bulb at 12V.