4 batteries or two with no OTR air?

belfert · November 29, 2010, 05:13:17 PM

I need to get new starting batteries for my bus. One of the suggestions I have seen over the years is to replace 4 group 31s with just 2 group 31 batteries if the OTR air has been removed. I'm thinking about getting two group 31 AGM batteries instead of four flooded ones. The AGM batteries can take more abuse, but hopefully I'll remember to reconnect my three stage charger after every use of the bus.

I do live in Minnesota so I'm not sure if I need the extra CCA from 4 batteries for winter starts which are rare for me. I know that some semi tractors only have two batteries, but I talked to my friend and his International had 4 batteries.

Has anyone gone from 4 to 2 group 31 batteries?

Len Silva · November 29, 2010, 05:31:24 PM

If you are in Minnesota then you definitely need all the battery you can get.

lostagain · November 29, 2010, 05:37:32 PM

Given an engine in good shape that starts relatively easy, ( or plug it in in cold weather), and you keep your batts charged up, 2 is enough. I have been using 2 group 31 batts on both my buses, and it is fine.

JC

jjrbus · November 29, 2010, 06:05:31 PM

After listening to much wisdom and experience in the bus community, when I designed my system I used a selector switch to tie the house and bus system together. I also moved the battery's to the engine compartment to reduce wire runs. I was able to use 2 grp 31's to start the bus (6V71)or had the option of all the battery's I would ever need with the flip of a switch. IF that failed, (never did) I could start the genset and recharge everything.
I also had a block heater, so unless I received an emergency call to save the planet in the middle of a blizzard . I could run the genset a bit and start a warm engine, used that option once.
If all failed (never did), I probably did not want to go anyplace anyway. Worked for me JIm

Eagle Andy · November 29, 2010, 06:11:26 PM

FWIW when I was thinking of getting rid of my 8Ds I talked to Clifford and he suggested 3 group 31. I do know that you want plenty of cranking amps for the start up so you don;t fry your starter . I did move my battries to the engine compartment and have gotton better preformance. just a thought

Brian Diehl · November 29, 2010, 06:30:47 PM

I run just two group 31 batteries on my bus. However, I can easily connect my house batteries to the start batteries if I ever needed to. Without this level of redundancy I would run 4 batteries. With my house batteries as backup I have no issue running two. Starting on two batteries in the cold has not been an issue so far (3 years).

Rick 74 MC-8 · November 29, 2010, 07:36:42 PM

Brian

I also changed my 8d's in for 2 group 31's have never had a problem I do use the block heater if needed I think once you get it started that DD will hold enuff heat for a few hours sleep if you need it till you get to warmer weather.

Rick 74 MC-8 8v71
Northern Illinois

Lin · November 29, 2010, 10:13:44 PM

I would think that the two batteries will be more than enough the vast majority of the time. It's that tiny minority that kept me from downsizing my batteries when we recently changed them. With all the money that the bus demands, I don't consider the cost of batteries that serious. Since our banks are 12v and 24v, we do not have the house batteries as backup though. That could change things.

Gary '79 5C · November 29, 2010, 10:48:57 PM

Brian,

I have a 6V92 to start and have chosen to maintian the original design of two (2) 8D's. I really want the bus to start when needed and not be delayed/stranded on a trip. I also do not live in Minn, been there like it & will visit again, If I did live there I would keep the OEM setup.
I have replaced one 8D five years ago, the other came with the bus, age unknown. I clean both 2X per year and check the water levels 4X per year. During long periods of storage I throw a charger on each battery, individually, and keep em charged. I have heated storage, so that helps greatly. I am still able to manhandle the bulk & weight of the 8D's so that has not become a consideration. If it does, my son will become involved. Bigger/Stronger...
I believe the maintenance & monthly or so charging is the key. If your bus is a 12V setup and connecting to the house batts is possible, the 31's would be a consideration. I do not wish to start with the house batt's connected thru the Vanner.

Just has worked for me, Best of luck with your decision.

Gary

belfert · November 30, 2010, 06:50:28 AM

After talking to some folks offline and the posts here I think I will stick with four group 31 batteries. I would like to go with AGMs, but financially I think I need to go with regular flooded batteries. If I remember to keep my three stage charger plugged in flooded batteries should last a long time.

Bill B /bus · November 30, 2010, 07:12:48 AM

In Maine until after Christmas. MCI 96A3 w/an 8V71 TIC and a 102A3 w/Series 50 both with block heaters and both with 2 Group 31's in the old AC compressor space. Backup is the crosstie to the house bank. Above 25-30 start without the heater with no problem. That temp and below is block heater and wait until noon, if sunny, for starting.
BTW no flooded wet cell batteries anymore either just sealed starting batteries or AGM for house.
Anyway my two cents.

Bill

luvrbus · November 30, 2010, 12:55:11 PM

Brian, you really need 4 group 31 batteries with the DDEC series 60 11.1 engine

good luck

Gary '79 5C · November 30, 2010, 04:14:26 PM

Quote from: Gary '79 5C on November 29, 2010, 10:48:57 PM
Brian,

I have a 6V92 to start and have chosen to maintain the original design of two (2) 8D's. I really want the bus to start when needed and not be delayed/stranded on a trip. I also do not live in Minn, been there like it & will visit again, If I did live there I would keep the OEM setup.
I have replaced one 8D five years ago, the other came with the bus, age unknown. I clean both 2X per year and check the water levels 4X per year. During long periods of storage I throw a charger on each battery, individually, and keep em charged. I have heated storage, so that helps greatly. I am still able to manhandle the bulk & weight of the 8D's so that has not become a consideration. If it does, my son will become involved. Bigger/Stronger...
I believe the maintenance & monthly or so charging is the key. If your bus is a 12V setup and connecting to the house batts is possible, the 31's would be a consideration. I do not wish to start with the house batt's connected thru the Vanner.

Just has worked for me, Best of luck with your decision.

Gary

belfert · November 30, 2010, 05:56:25 PM

Quote from: luvrbus on November 30, 2010, 12:55:11 PM
Brian, you really need 4 group 31 batteries with the DDEC series 60 11.1 engine

Why would the 11.1 require any more batteries than the 12.7?

I went ahead and got four batteries. The engine started up in no time with new batteries at 25 degrees. The engine is still running right now so I haven't hooked up the three stage charger yet.

luvrbus · November 30, 2010, 06:35:05 PM

If no one has changed the old style starter on your 11.1 it needs help low voltage and amps will kill the old style MT 42 starter most of the 12.7 had a reduction type starter.
I guess all manufactures are different FWIW the Eagle used 3 gp 31 batteries on a 12v system with factory heat and air so I don't buy the idea the use of 8D's was because of the ac and heat they were for starting and some Eagles had 2 8D batteries.
I like the 8D but they are just too heavy for me to handle now.

good luck