06 Mega cab false start

Hello all,
My 2006 Dodge 2500 mega cab 5.9 seems to have developed a slight starting issue. It's about 25 degrees here and after it sits a while it seems to crank, then fire then quit. It's like maybe the starter doesn't stay engaged quite long enough. Once it does it it will continue to do it each attempt after until you turn the key off and wait about ten seconds and then try again. Once again the intake heater comes on for its time and the truck starts as it should. The intake heater seems to work as it should. I'm wondering about batteries but my cranking speed seems OK. Anybody else had an issue like this or know what it could be. Money's alittle tight now so I'm hoping for something I can look into on my own. Thanks in advance for your help.