KTink18

I recently hooked an Alpine MRX-M110 amp with 2 12 Alpine SWS-12D2 subs in my 2006 Ram 1500. They are wired with 4 guage wire straight to my battery. It's been just over two weeks since I installed them and I decided that they were ready to be turned up. The amp provides up to 1100W while each sub has a peak of 1500W so I put the gain to about 75%. It ran fine for two days. Today however bass heavy songs are causing my kenwood double din deck to restart and my dash will dim. I turned the gain back down to half and it seems to run fine. Is this being caused by my amp drawing too much power? My friend thinks it could be the alternator while another thinks it's the battery. Opinions? I'm not very knowledges in terms of car audio.