Bombing the battery

[15w40]

I am looking for opinions on replacement batteries for my 98. 5 Diesel. I have done some research and read all the posts about the Optima batteries but have some concerns. The list below is a comparison of Cold Cranking Amps, Reserve Capacity, and physical size of batteries. The Cold cranking amps is a measurement of how much current can be sucked out of a fully charged battery at 0 degrees F with the voltage not falling below 7. 2 volts. This is important for cold weather starting or when operating a winch. The reserve capacity is the time it takes, in minutes, for the battery voltage to fall below 10. 5 volts while supplying 25 amps. It is measured when the temperature is 80 degrees F. This is important if you are far from home and your alternator fails or your headlights are left on with the engine off.



Stock Dodge Battery:



BCI group 27, 12 1/16 x 6 13/16 x 8 7/8

CCA 750

Reserve Capacity 150 minutes





Optima Red top:



BCI group 34, 10 x 6. 8 x 7. 8

CCA 750

Reserve Capacity 104 minutes





Optima Yellow top:



BCI group 34, 10 x 6. 8 x 7. 8

CCA 550

Reserve Capacity 120 minutes





Interstate 31P-MHD:



BCI group 31, 13 x 6. 75 x 9. 375

CCA 950

Reserve Capacity 195 minutes





Both of the Optima batteries are slightly underrated when compared to the Dodge battery. The Interstate 31P-MHD is about 1" too long to fit in the battery tray but by cutting the front lip off the tray it will fit in the space allowed for the batteries. Unlike other group 31 batteries, this one has the standard automotive style terminals and should not require any fancy adaptors to make the connections. I am sure it weighs more than the Dodge battery and a lot more than the Optimas.



Has anybody tried one of these commercial batteries in their truck? Is there a reason this won't work, before is spend the dough?



edit:

I was all set to buy the Optima batteries, but their lower ratings bothered me. It seems that if Dodge could get away with a smaller battery they would have done that (and saved a few bucks). I have read that there are a lot of people running the red and yellow top batteries but how long do they last.

 

[RGRAT1618]

I used to work in a battery store, I still work there part time. We sell the optima battery. I have a 1985 ford diesel beater truck. In it I have 2 yellow top batteries. They have high cold crank amps and are part deep cycle to handle any heavy part time drain in my case a snow plow. I also have a 1200watt inverter. I do not plug the truck in the winter and still starts fine. As soon as I get the money togather I am going to put 2 yellow tops in my CTD.





Rob

 

[Bad340fish]

The design of the Optima prevents them from having a good reserve capacity for some reason. You can pull any Red Top off of the shelf and put a 1200CCA load on it and it will hold it great. Same goes for any Interstate Product... they are underated on the label ALOT in most cases. I have worked for Interstate for 4 years now and have tested and charged ALOT of different kinds of Batteries. I am not sure why but the Yellow Top Optimas always come back way sooner than the reds do. The Reds have a better warranty and are cheaper than the yellows also.



The 31P although expensive would be a great choice. When your thinking CCA remember that the way the batteries are wired in our trucks you double the CCA and reserve capacity on them.



Another thing to remember is the only REAL maitanence free battery out there is the Optima line. Any standard lead acid battery that says Maintenence free is really Maintenence Impossible since you can't add water even if you want to.



Personaly I am going to put red Tops in my truck when it comes time. I have never had a Customer not happy with the Red tops before. They are Cleaner since they never gas out at all like a reg battery also. And I don't care a whole lot about reserve since my truck always starts in just a few cranks no matter what. If I had a PSD It would be a different Story

Clark

 

[15w40]

I think I have found the answer. A Cummins publication, "Operation and Maintenance Manual ISB Engine", bulletin No. 3666170-03, gives the recommended battery capacity of 1100 Cold Cranking Amps (CCA) and 260 minutes or reserve capacity (RC). Because the diesel has 2 batteries each battery should supply half of these ratings or 550 CCA and 130 RC as Bad340fish points out.



The stock Dodge battery easily exceeds the recommendation. The Optima yellow top and red top are both a little low in RC. I'll bet that any fresh, off the shelf battery, will exceed the capacity numbers. The problem comes 3 or 4 years down the road when the batteries get weak. I leave my truck parked in sub zero weather with no block heater connection available.



I think I will get a price on the Interstate 31P-MHD. Please excuse all the specifications in my posts but being an electrical engineer for the last 30+ years has me wired that way.



Thanks for the posts.

 

[Bad340fish]

$$

Suggested Retail on the 31P-MHD is $99. 95 a piece. Some shops sell for a little less than retail but not many. Own a buisness or know someone that does?? Some warehouses will give you wholesale cost for bieng a buisness owner. Like I said. . some not all. Its alot cheaper that way

Clark