Battery for light

Can someone suggest a good battery to use on this 10 dollar light I just picked up? I will be using my kayak lol. I would prefer to use something a little lighter than a huge rv deep cycle battery but I also would like it to last for 4 hours or so... The package says it pulls like 4 amp an hour.

I don't see why you couldn't use one of these...Amazon.com: 12 volt 18 Ah Rechargeable Battery: Electronics
I use a regular 12v marine battery and never run it down even after 16 hours of use.

Thanks!