Sizing a Battery

[Bakaruda]

I am looking for advise on selecting the correct size battery for my project. Car has a GenIII Hemi, A/C, Electric fan, Electric Fuel pump, LED tail lights, HID head lights.....

[blitzer454]

Really the only thing you need to worry about when selecting a battery is one that fits the battery holder and the CCA rating. Higher CCA rating is better for cold starting. Of course there is also different battery types like the normal acid type battery versus AGM and lithium type batteries. The latter will allow more flexibility for mounting the battery at different angles.

Once the engine is running the alternator takes over and powers all the electrical components you mentioned. So a better question might be, what size alternator do I need? To answer that question you need to add up the constant current consumption of those components and any other component that is mostly turned on and get an alternator that meets or exceeds that current rating.