2005 dodge diesel battery ?

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Nov 26, 2009
The early Dodge diesel in 91 had a single battery setup, mine is a 2005 and has dual batteries the original ones are still in the truck. ( 6 years old ). They are beggining to die, slower cranking speed. Has anyone ever just went to a single battery setup on a diesel, it would seem if you bought 1 battery with a high cranking amp you would not need 2 batteries. It only get into the 30's here and on rare occasion will get in the 20's, the biggest draw on the battery is the grid heatersbut I usually crank and drive slow till warm so the grids dont set there and cycle off and on.
The bad one would probably pull the good one down and at 6 years old they are ready to retire anyway. Be prepared to pay $100 plus for any battery these days they have doubled in price the last 6 years.
Among other reasons given, diesels have high compression ratios requiring more starting power. Go cheap and you'll kick yourself some dark lonely cold night. Is your alternator OK? Best to have your whole system load tested.
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if it has the capability to run dual, I'd run dual. You might buy one starter battery and one combo starter/deep cycle (marine). the combo batt will have a greater reserve for pulling up that cold heater without tapping the starter as deeply, while the starter batt would have the cca to spin the engine. (note, would have to be identical chemistries... like both unsealed... not one sealed and one not) might not be much cost savings, tho. so-- just going with two decent batts that match stock would likely be best. echo above, higher CCA compromises other things-- plate thickness (porosity) and reserve capacity.
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Diesels don't require as much power as they used to in order to start. Newer starters with high-speed semi-permanent magnet motors and internal gear reduction deliver the torque and cranking speed without drawing as many amps as the old days. Plus the start assist systems are more efficient and don't drain the batteries quite so hard before you even engage the starter. In a warm climate and on a Cummins that uses the grid air heater sparingly I imagine you could probably get away with a single battery just like the early Cummins Rams, especially if you get a quality battery with plenty of reserve capacity and CCA rating. I'd stick with dual batteries in South Dakota, but your sig says Alabama ;-) Also as tommygunn said, you may only have 1 bad battery now and its pulling the other one down. Just getting rid of the failing one might show you how well it can work on a single battery- even an old one. Separately load test the batteries to see which one is bad, or if you can remove the cell covers you can test them with a hydrometer and find the cell(s) with low specific gravity.
Guys I wanted to go to a single battery, and do away with the duals since the weather is not as cold here as other parts of the country. I was thinking of a 850 to 950 cca battery should be enough to crank the truck. I am sure one battery wouldn't last as long but it is easier to buy 1 battery every 3 or 4 years rather than 2 at a time cause like someone here said wow those batteries have gone sky high.
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