Building a battery pack for dlink dir-412 router

[dullusb]

Hi guys
I was wandering if any of you have any experience with building battery packs. I have a dlink dir-412 3g router which is powered by a 5v 2.5A adapter can anyone assist on what I will need to power this using batteries so that it becomes mobile

 

[KhoisanX]

You were wondering?

Depends on how portable it needs to be and how long it has to run on battery power. The simplest solution would be to use a UPS, it would run for a long time but it would also be very bulky. A laptop battery with a with a suitable transformer would also work and be smaller, lighter and you would no longer need the adapter.

Alternatively you could buy a portable 3G modem/router.

 

[dullusb]

I would want it to be mobile, however it does not have to last more than 2 to 3 hours at a time. A UPS will definitely not work. Do you have an idea of where I can get information on building a battery pack using a laptop battery. Dont want to purchase a new one just want to this for fun

Thanks for the assist