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Topic: Do I need two 8D start batteries? (Read 530 times) previous topic - next topic

Do I need two 8D start batteries?

Went to fire up the bus yesterday and start battery was dead.  Poking around today, I find that one of the under step batteries is connected to the rear mounted start battery.  It reads low voltage  by itself while the rear mount reads proper .   
 My question; do I need the two bats tied together?
  I thought that the under stair batts were the coach power but it is not wired that way.
 Thanks . MM

Re: Do I need two 8D start batteries?

Reply #1 –
Quote from: Protech Racing –
Went to fire up the bus yesterday and start battery was dead.  Poking around today, I find that one of the under step batteries is connected to the rear mounted start battery.  It reads low voltage  by itself while the rear mount reads proper .   
 My question; do I need the two bats tied together?
  I thought that the under stair batts were the coach power but it is not wired that way.
 Thanks . MM
Depends on your model/brand engine, how well it normally starts, do you travel to high altitudes in winter, etc.

Detroit 2 cycles like ours do well with two 8Ds or three 34/31 etc. Smaller engines like the 5.9 and 8.3 Cummins do OK with two 34 series. You can NEVER have too many CCA. We frequently camp at high elevation and in cold weather. We don't have glow plugs(most direct injection diesels don't), intake heater, etc so the more CCA, the better.

Non-turbo engines usually have higher compression ratios so are easier to start cold.

A great starting engine in three seasons may not so so well when winter and other factors are considered. Good to have cables and terminals clean to avoid delays.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Do I need two 8D start batteries?

Reply #2 –
Cat 3208 T , fires right up at less then two revolutions.  (When the fuel filters are air free)

Re: Do I need two 8D start batteries?

Reply #3 –
Quote from: Protech Racing –
Cat 3208 T , fires right up at less then two revolutions.  (When the fuel filters are air free)
If it does that in winter on one 8D, it's your ticket.

P
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Do I need two 8D start batteries?

Reply #4 –
My 1981 Foretravel had a 3208 Cat and it came to me with a regular car battery and a 12 volt marine battery for the house. I never had a problem starting it. I switched over to 6 volt golf cart batteries for the house and stayed with one 12 volt car battery to start the Cat. Worked great for 10 years.
1993 U225 Build #: 4285
500 Watts Solar
Honda CRV AWD
Former 1981 Foretravel Travco
Retired, Full Time Off Grid Snowbird

Re: Do I need two 8D start batteries?

Reply #5 –
I think yes
Tom
1998 U320 40'

Re: Do I need two 8D start batteries?

Reply #6 –
Thankyou for taking the time to answer.  I will clean up the post and give it a whirl ..
 

Re: Do I need two 8D start batteries?

Reply #7 –
Quote from: Protech Racing –
Cat 3208 T , fires right up at less then two revolutions.  (When the fuel filters are air free)
Started my 3208:at 15 degrees on a single 8d but it took a bit
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake