I also thought it had something to do with diesels having high compression and typically large engines, large flywheels, flexplates, heavy rotating assemblies etc. and large starters etc. They are harder to turn over than your typical gasoline engine with lighter parts and lower compression.

 

If you live in the south, you could proably get by with one battery, but why? Batteries do not cost that much, copared to everything else related to these beasts. If one battery leaves you starded, is it worth the risk?
The engineers who put thse together did the batteries right.

 

1st gen had only one batt,started at -35 ,has same grid heaters,overkill,someone looked a ford/gm and said we should have 2 batt. because it looks impressive

 

also need two batt.s if your like some of us that havent grown up fully and have a amp and two subs requiring some power. Sad part is that if i turn my amp and radio up to max it will still dim all the lights on my truck

 

Yes, but our old trucks have a big ol' group 31 battery, same size as you would find under a heavy truck. Of course, a heavy truck uses 2 or 3 of them - but still it's a big battery. Even a low buck one has at least 1050 CCA.

 

my brother has a 1998 ram 2500 and he has replaced one of the batteries

 

^ ^ ^ ^ ^ Never a good idea to replace just ONE of the batteries if it has two, it can mess up a lot of stuff on these trucks! Just saying!

 

Two is one, one is none.....they have two to power the grid heaters when cold.