Starting batteries for an 8V92T

[Ray D]

I have a 1989XL Prevost that has 4 starting batteries with an 8V92T.  Without the over the road A/C sytstem do I still need 4 batteries or can I reduce down to 2?

Thanks,
Ray D

[skihor]

I'm running my 6V92 with 2 group 31 batteries. While it starts just fine... Wait until it gets cold and you don't have the block heater plugged in. I just went through that scenario last weekend in the mountains. Woke up to 1" of snow and around 25 F.
I tried the crank for 10 seconds, wait for 30 seconds, repeat method. Well I ran out of battery before it started. I cranked up the Gen and we watched a movie while the block heater warmed up. After 2 hours the batts had recovered enough and the block heater had put some heat in it, then it started easily. I'm going back to 4 start batteries.

Don & Sheila

[tekebird]

it is a huge misconception that large batteries (8D) were because of the Coach A/C units.

even with the very large reserve capacity of the 8D'san A/C or Heater Blower motor would drain the battery in a very short time.

The large batteries have a higher reserve capacity, more CCA and are less susceptable to power loss due to cold temps.

you can probably crank over a 6-71 that is in good shape with a motorcycle battery at 90 degree OAT

but try doing it at 50 degrees.

smaller batteries have only two benefits in a conversion from my perspective.  They are smaller and lighter.......and cheaper per battery

IN a head to head test the Factory battery system will outstart any modified setup.

[luvrbus]

i kept my two 8ds in my Eagle with a 8v92 and never had a problem with starting, i know that they are heavy but low voltage will kill a starter i would keep what you have

[bobofthenorth]

I have 2 8Ds and on those rare occasions where I really need them I'm really glad I have them.  2 things you can't have too much of in my opinion - batteries and tires.  My papa taught me to buy the best I could afford of each and the advice has served me well.

[tekebird]

thngs you can't have too much of or too good of:

Sex
Tires Batteries
Room
Storage
HP ( at least that's what the mases thing with all the repower threads)
toys in general

[jjrbus]

I only have a tiny little 6V71. After looking over the options I went wth 2 group 31's with a selector switch, so I can tie my house and bus batteries together. I moved the start batteries to the engin compartment so now there  is 2 foot of cable to the starter instead of 20ft, that must count for something. I also have a block heater and generator.
There are lots of ways to do things, check them all out and decide which works best for you. I'm sure our friends in Alaska have a different setup then the ones in Arizona! There really is no right way to do it.

[TomC]

I have 2 size 31 Interstate 950cca starting batteries and 2-8D Lifeline AGM deep cycle batteries.  The two sets of batteries can be tied together with a dash operated solenoid for either charging the 8D's going down the road or to be able to help the size 31 starting batteries in the cold.  Personally would not carry the extra two starting batteries just for starting in the cold when you already have the deep cycle batteries that can also start in a pinch.  Good Luck, TomC

[Ray D]

I like TomC's idea of 2 batteries and being able to get assist from the house batteries, the start and house batteries in my rig will all be in the same compartment.  Anyone see a problem with this???

Thanks,
Ray

[TomC]

Actually there is a problem with that- if you have a 24v bus with 12v for the deep cycles to run the bus.  You probably could do it, but would have to use 2 solenoids- one individual for each battery to keep the 24 volt bus system viable.  Good Luck, TomC

[H3Jim]

My house system is also 24 volt.  Lots opf good reasons to go that way not hte least of which is the ability to connect to the bus alt and start bats when necessary.  24 volts needs half the wire size for a given wattage.  My water pump, refrig, some lighting and the diesel heater all use 24 volts. 

For some of the bus wiring I also changed the power source from the start bats to the house bats, such as the lights in the bays.  I guard the charge status of the start bats very religiously.  Last longer and less worry about not starting one day.

[white-eagle]

i have 3 31's and they work fine until it's about 20 deg.  that's why i installed the block heater last year.  i've got an 8v92t with bus air/heat.

no real house system yet to tie in.