Will running a bigger alternator over charge your battery? I put a 145 amp in my 2003 1500hd since my stock 105 amp went bad today. I did the upgrade to plan for the e-fans in the future. Also my truck has two batteries in it.

 

you will be fine. very common upgrade.

 

Perfectly fine. Mines clocked in around 280-300amps with dual Optima Yellow Tops. Just be sure to upgrade your wiring from alternator to battery. For 145amp I'd suggest somewhere in the 2 gauge range, which is what most pre-fabbed cables come in.