ComputerBB

i bought a little shuttle barebones system a couple of weeks ago and fitted everything necessary to get it going, has been working really well until last night when i turned it off and turned it back on again later. The time was the same as when i had turned it off?!?!? i thought the mainboard battery might need replacing but surely not after 2 weeks?!?!? can anyone help, please I'm really worried this is effecting more than the time on my computer.

If the battery was bad you would have to reset the BIOS,the time is controlled by a chip on the M/B. if you don't keep time it's the M/B