No, they are wired in Parallel. They run at 12v, but double the amperage. That many amps is required to turn over a diesel when it's cold since there is no 'spark' to assist the starter has to do allot more work. Some equipment has up to 6 batteries just so it can't turn over.

The same reason your remote control needs 2 AA batteries, not one. The remote is the same voltage as the battery, but it still needs two.

Series:

Parallel:

 

^what he said. Not to mention glow plugs suck up an insane amount of power... running one battery wouldnt exactly do too well for long, they'll start it(done it b4) but the battery wouldnt last lol.

 

the glow plugs and starter require a ton of amps to run. so two batts = double the hp behind the volts.

 

:agree:

High compression engine needs the extra juice to turn it over, and the glow plugs suck up something like 1000 watts to start.

 

Seen guys run four batts in their pickups before.

 

Did that for a while, but the day after the 3yr warranty on those Optimas was up, the truck started having starting issues.

 

Oh ok thanks guys nice diagram

 

I'm running Die Hard's from Sears, they were roughly $250...

3 year replacement warranty, and I believe 100 month pro-rated warranty.

And it DEFINITELY starts quicker!

 

What cca's you got?

 

yeah thats what i figure my truck would not start i have 2 batterys from ford from 05 lmao so i had them checked at pep boys one was 519 cold cranking amps other ran 600 cold cranking lmao they were both soposed to be 850 so i replace them fired right up

 

I have had pretty good luck with Optima's so far.