Can I power a Mega2560 R3 with a 11-16 volt RE Battery System?

Can I power a Mega2560 R3 with a 11-16 volt RE battery system? The alternator charging makes a few volts ac ripple, and depending on loads, the DC voltage varies from 11-16 volts. Would this varying power source impair the accuracy of analog measurements?

Re: Filtering 5V and 12V in a noisy automotive environment

sonnyyu: This might be not the case, OP solve the 5v problem and facing 12v only.

few plans for OP;-

plan A Power Supply Filter, L-C Type. It is cheaper and simpler, and worth to try first. ( credited by db2db )

plan B Isolated DC-DC converter. offer additional protection and higher noise reject rate.

plan C Wireless power technology, it might be worth to note on calendar since you might need to wait few more months. It offers the possibility of "cutting the last cord", thereby removing the last remaining wired connections required to power and recharge. It is base on similar technology as Isolated DC-DC converter and noise reject rate is great. Now you need to make sure Arduino design is wireless and power cable is last cord.

No more wait, Wireless power module is available today and price is acceptable.

That would be nasty as a power supply. Run that voltage into a 8V linear regulator and then to the barrel jack of your Mega. http://www.digikey.com/product-detail/en/UA7808CKCT/296-34922-5-ND/3635063 Make sure you use input & output capacitors.