*D Batteries VS group 31

[TomC]

Virtually all new big rig trucks use 12v starters. At Freightliner (and I assume most others too) when you specify a sleeper cab, you automatically get a 4 battery system. The standard batteries are 950cca, which works out to be 3800cca. But-they are wired with two cables from the starter with each cable servicing two batteries in line. So wiring wise, that would give an effective 1900cca with twice the reserve capacity. Main reason for 4 batteries on the sleepers is to allow the drivers to run their TV's and computers. The sleeper trucks also have a 12.3v cut out for the cab. But, you leave the headlights on, you can still run down the batteries.

On my old ('85) Kenworth, I have a jumper solenoid so I can run 12v system but with a 24v starter. I run 4-1100cca batteries. Needless to say, the big Caterpiller (14.6 liter) 3406B turns over easily. Good Luck, TomC