Can low batteries in a camera cause grainy pictures?

I have a Fujifilm FinePix S2Pro camera and while taking pictures my batteries where running low, and since I didn't have any spare, I had to make do with the old ones till they were completely dead. I have experienced it before but am not sure if that's one of reason. I had it at f4.5 and ISO 100, sunny day but taking indoor pics.

Grainy photos are usually caused by underexposure. If your low batteries affected the camera metering or shutter timing, then you could get underexposure and grainy photos.

If you were shooting indoors at ISO 100 and f/2.8, then your shutter speed should be around 1/30, maybe 1/60, depending upon how much light was indoors. If your shutter was too fast, then you'd get underexposure and grainy photos. And the S2 Pro is not forgiving of bad exposures. I know; I own one.

I have never seen this before. Even the batteries are low, my cameras are still fully functional. Charging the flash may be slower.

No it may disable the shutter though. If there is juice in the battery the camera should respond .

Low batteries could never cause grainy pics. But you might wanna try upping the quality in the Menu. Or try ISO 400 or higher if it has it. This should increase the quality.