Main batteries

petarm1 · July 04, 2019, 05:19:52 AM

I need to replace my main starting batteries, i dont like the 2 huge D batteries, has anyone done something diffrrent? I am thinking of getting 4 yellow top 12 volts insted to turn over the 12.7 detroit.
Whats your thoughts

richard5933 · July 04, 2019, 05:28:33 AM

Other than them being heavy, what's the problem with the 8D batteries?

I'm starting to learn that the engineers didn't make decisions on things like batteries without reason, and I've kept mine just as they were from the get go.

DoubleEagle · July 04, 2019, 05:53:44 AM

Three group 31's will do it, if you are a 12V system.

chessie4905 · July 04, 2019, 05:59:03 AM

If you don't have factory ac anymore, you may be able to switch to 2 group 31's. Depends on what other loads your starting batteries are required to support. On Richard's with all the relays and voltage reducers and who knows what in the future he adds, he needs 2 8ds. On our 4104, we used the 2 8's, as they were also our house batteries. If you use separate house batteries, you can wire in a relay for boost in case your starting batteries are low.

buswarrior · July 04, 2019, 06:13:45 AM

It all depends...

A pair of 31's will work fine...

IF, you have a way to maintain them during storage times...

If the coach AC is removed...

If the house system can be called on to boost...

If you are not planning a cold start in Alaska mid winter...

Otherwise, don't mess with success...

Happy coaching!
Buswarrior

Brian Diehl · July 04, 2019, 08:01:27 AM

I 100% agree with buswarrior based on my own experiences. Good advice.

TomC · July 04, 2019, 01:14:25 PM

2-31's will turn over a 6V-92TA just fine. Good Luck, TomC

Ed Hackenbruch · July 04, 2019, 03:08:37 PM

I had 2 group 31s for 10 of the 12 years we had the bus. Fired up the 8v71 easily.

chessie4905 · July 04, 2019, 05:32:07 PM

Different than a series 60. Heck the 8v-71 starts on 1/2 a revolution.

petarm1 · July 04, 2019, 05:39:04 PM

Let me see if i understand what is being said. Keep the 8d they work.
Thanks all. I will replace the batteries with original.

Geoff · July 04, 2019, 05:59:46 PM

Quote from: petarm1 on July 04, 2019, 05:39:04 PM
Let me see if i understand what is being said. Keep the 8d they work.
Thanks all. I will replace the batteries with original.

Might as well. Then you don't have to worry about making up new cables.

chessie4905 · July 04, 2019, 06:08:34 PM

Now to decide what brand.

windtrader · July 04, 2019, 06:44:13 PM

8v71 with 39MT geared starter works fine with 2 group 31. Was concerned initially but have a full house bank that can back up primary batteries if needed. Experience in non sub-freezing weather is frighteningly instantaneous start once button is pressed. Pretty sure the geared starter makes it a lot easier to kick over.

bigred · July 05, 2019, 05:31:34 PM

Our local Sams club stocks a good supply of starting batteries including the 8D's .That is the best price and the best guarantee I've found.

petarm1 · July 06, 2019, 05:21:39 PM

8d batteries at a local canadian tire will run me 300.00 a piece. Not sure if make of battery matters. The bus is going to sit more this summer than run but when i need to start it i dont want to boost it every time.