Battery question

[Flight102C3]

   Hello everyone.  I have questions about batteries in my 102C3 with a Cummins N14.  Still using the old Ds.  Will be putting group 31's in.  I do not use my bus in the winter.  Do I need 2 or 3?  Since I will build a new cables do you think I should use  stud mount or post? Thanks ahead of time I appreciate everyone helping.

[Oonrahnjay]

   Hello everyone.  I have questions about batteries in my 102C3 with a Cummins N14.  Still using the old Ds.  Will be putting group 31's in.  I do not use my bus in the winter.  Do I need 2 or 3?  Since I will build a new cables do you think I should use  stud mount or post? Thanks ahead of time I appreciate everyone helping. 

     Do you have a 12V or 24V start system?  With the right terminal on the cables, stud mount seems good but I'd like to hear from other people on that.

[Flight102C3]

 It is a 12 V system.  I rewired the whole bus to 12 V.

[luvrbus]

I would go with 3 on a 12v system JMO

[HB of CJ]

Dunno if this helps any but my old Crown Supercoach had the old Small Cam 855 non turbo Cummins.  12VDC starter.  Two (2) 8D batts.  It would crank slow but start on one battery down to about +45F.  I had one bad battery and removed the cables until I got around to replacing it.  Seemed to work OK.

[Oonrahnjay]

I would go with 3 on a 12v system JMO 

     That's why I asked. Yeah, you have to have the amps with a 12V system to make the watts you need for the load.

[Iceni John]

And if you're making new battery cables anyway, why not also make a switchable connection between the house batteries and the starter to help in cold weather?   I went from two 8Ds to two Group 31s, but I can also switch either or both of my house battery banks to the starter if it needs some more oomph in cold weather.   I use the Blue Sea 9002 and 9001 switches, and 4/0 cable throughout.

John

[luvrbus]

He needs the extra amps 12v starters draw twice the amps of the 24v starters plus he is starting a 14L engine,I wouldn't chance killing the ECM for a extra 100 dollar battery.My 60 series a 24v system will struggle with 2- G31 starting so I use 4-G31   JMO  

[Flight102C3]

 The engine is a Cummins N14 STC .  It has  no ECM . I dry camp 1deep cycle battery. Thanks

[TomC]

Freightliner uses 2-31 batteries on the 6.7 and 8.9 liter engine. When going to an engine larger they use 3-31 batteries even up to 16 liter engine. Only time they use 4 is in the sleeper trucks, and that's just to be able to power the lights, TV, etc at night. I use 2-31 batteries on my 8V-71, but also have a jumper relay to connect the 2-8D deep cycle just in case-and to charge the deep cycle with the big engine alternator. Good Luck, TomC

[daddyoften]

And I can tell you from experience that 2 batteries in my 2015 kenworth service truck with the 8.9 is not enough in the winter time. My old international had three batteries and that was perfect. With only 2 we have had problems in two different Kenworth's. These should have three!

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[thomasinnv]

I put 2 31's in my MC8 and in cold weather they give out fast. never was a problem because it always lit right off, but after the engine rebuild it was necessary to prime the fuel system and they ground down to nothing in a matter of seconds. when I do get my bus back from the shop it will be getting 2 new 8D batteries straight away.

[MB LeMirage]

All of my Freightliner Cascadias are running 3-group 31's. We have tried using 2 but in the cold up here, 2 does not cut it. We are also running DD15 515 HP units and they need juice, lots of juice.
Ryan.

[opus]

Ahhhh...I remember the days of having a compression release.

[Lee Bradley]

Ahhhh...I remember the days of having a compression release.

...and four 6 volt batteries with a series/parallel switch. I would spin the engine (262 hp) until the oil pressure gauge twitched and release the compression release and it was running with full oil pressure.