I am looking at replacing the big 8ds in the MCI9. I would like to get max CCA (now around a 1000) but the batteries are too long. Has anyone replaced the 8ds with series 31s that fit side by side in the original space of the 9? What is the minimum CCA necessary to crank over the 6v92 in weather above 40 degrees?
Thanks
Grant
They need 950 CCA to crank min keep this in mind the CCA just last a few seconds reserve is also important in case you need some more starting power some of the guys get by with 2 group 31 for a 24v system but owning DD for years I use 4 group 31 for a 24 volt system and 3 for a 12 volt system saves the starter batteries are a lot easier to change than the heavy starter laying on your back.
good luck
You can get 8D Cat branded batteries that are 1400 CCA, sealed maintenance free, top post. I put them in my Crown, it's a hard startin' old Cummins 743.
I put four Optima group-31s (http://www.optimabatteries.com/_media/documents/specs/D31T.pdf) in the engine compartment of my bus (4 feet of 4/0 wire between battery and starter, including the ground return path and inter-battery tie :)). On a warm day I can start with just two, in no time at all. I have a BlueSea Systems 3003 switch (http://bluesea.com/category/1/products/3003) in the engine compartment which lets me "excersize" one pair at a time, or on cold days - combine all four for the extra oomphff.
The four D31Ts take about the same space as a single 8D. The listed CCA is 900, but with both banks turned "on", I get 1800CCA. You can "go nuts" like I did and toss in a couple of 500Farad UltraCapacitors (http://www.tecategroup.com/capacitors/datasheets/maxwell/BMOD0250-16.2V.pdf), which will help with the first few revs of the engine (they will kick out a bit under 4000Amps for a second...).
-T
Quote from: luvrbus on April 04, 2011, 02:50:43 PM
owning DD for years I use 4 group 31 for a 24 volt system
good luck
What about 4, 6 volt T-105 golf car batteries?
The "Golf Cart" T-105 is a deep cycle 6 volt battery designed to be discharged over about 20 hours, (or 8hrs?) which I THINK is how they are rated.
A starter battery is a different beast; being designed for a bunch of amps for only a few seconds or maybe a minute at best. Like the Turtle vs the Hare.
however....IF you had...say 12 T-105 Golf Cart type batteries as you main battery bank (say diesel-electric coach) THEN would they work? Dunno fur sures. HB of CJ (old coot)