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Topic: New Start Batteries (Read 1646 times) previous topic - next topic

New Start Batteries

After a slower cold start cranking episode, decided to replace our 8-year old Optima start batteries.

Found these expensive batteries for $190 with all the same Dec-2018 build-date and decided to clean up all connections and use new long 3/8" bolts.

Years ago when we had an engine crank issue, we added a third battery and made bus-bars to interconnect.  We connect positive on battery #1 and negative on battery #3.

Our OEM setup had a dedicated cable to starter solenoid and a second cable to isolator panel that feeds everything else.  We put a disconnect switch on the second cable that has come in very handy, especially for extended parking under cover without hookups.  Happy we did not have to introduce a splice with a switch on the dedicated starter cable.

Re: New Start Batteries

Reply #1 –
Barry very nice and clean. I have three reds also. Buzz bars are a great idea.
1995 U320 40', 2013 chevy sonic toad, my real love are corvettes have owned 30

Re: New Start Batteries

Reply #2 –
Thanks Joe SZ,

Yep, the M11 came with 3 red tops and the C/ISC-8.3 smaller Cummins came with 2 red tops in the same tray that can hold 3 batteries. 

So it was easy to add a 3rd battery like the big-boys have.

Re: New Start Batteries

Reply #3 –
I was wondering on the size of the red tops. I have (1) 8D battery for start. Thought of adding additional. Are your 3 red tops able to fit in the size of battery tray which I have in my 96 320 or would some modifications be necessary. Also, by looks of the pictures, your buss bar is aluminum, yes?

Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: New Start Batteries

Reply #4 –
Barry, I only see 1 positive cable, where does your dedicated positive to the starter come from? Also what is that black box on the positive cable downstream from the battery?

Keith
The selected media item is not currently available.Keith & Jo
2003 U320T 4025 PBBS Designer series
Build 6203    Cummins 500hp
2000 U320 4010 WTFE / Build 5762 —Sold—
Motorcade #18070   
Pasadena, Texas
2015 Jeep Wrangler Sahara-Sunset Orange pearl coat
Don't argue with a fool, people watching might not be able to tell the difference.

Re: New Start Batteries

Reply #5 –
Quote from: ohsonew –
I was wondering on the size of the red tops. I have (1) 8D battery for start. Thought of adding additional. Are your 3 red tops able to fit in the size of battery tray which I have in my 96 320 or would some modifications be necessary. Also, by looks of the pictures, your buss bar is aluminum, yes?

Larry
My coach had the three red tops when I bought her.  I switched to an 8D starting battery shortly thereafter.  I just recently had to replace the 8D and went back to the three red tops.  They easily fit in the same place, only the height varies and that is no problem in the start battery area of my U320. 

Richard
Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
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Re: New Start Batteries

Reply #6 –
Richard,

Are these are group 31's or 34's?
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: New Start Batteries

Reply #7 –
Brett,

I am sorry to say I do not know for sure what battery case size they are.  I will have to check.  I guess I was not a prudent consumer and just bought what I thought were the standard O'Reilly starting batteries. 
Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
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Re: New Start Batteries

Reply #8 –
I believe my red tops are group 34 and as stated I have three just like Barry.



1995 U320 40', 2013 chevy sonic toad, my real love are corvettes have owned 30

Re: New Start Batteries

Reply #9 –
Turns out my Red Tops are group 34 as well. 
Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
The selected media item is not currently available.

Re: New Start Batteries

Reply #10 –
Richard, thanks for the info. When the start battery needs replaced, I will check into it. Do the 3 redtops crank better/worse/no difference than 1 8D? What is the big difference to make a choice either way?

Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: New Start Batteries

Reply #11 –
When I needed to replace my 2 start batteries I went with 2 Group 31 Truck batteries, maintenance free @$110 each.  950 CCA each.
I have seen these batteries on sale as low as $80 each.  Haven't touched the boost switch since then. 

Cya down the road............................ ^.^d
Ted & Karen
2001 U270 36' - sold after 12 years full timing

Re: New Start Batteries

Reply #12 –
Brett, duplicating our OEM red tops, these are our 3rd purchase of Optima Red dual-terminal groups-34/78.

This is a popular Optima battery model and has several different part numbers: 34/78-980, 8004-003, 9004-003, 27990, N9934/78RED.

Relating to the small gauge wires connected to the battery terminals:

The ground is direct wire to King cruise/throttle control to insure a strong ground connection.

The positive is directly connected to alternator voltage-sense terminal, and inside coach volt meter.

Re: New Start Batteries

Reply #13 –
Keith,

Both OEM heavy duty positive cables were originally connected to the 'first' battery closest to the engine, along with the negative cable on the same battery.

The starter cable is not visible in the terminal photo, but the edge of the cable's terminal is visible between the first nut and the 6mm red cable. If you look at the 3-battery photo, you will see two large black cables on the right side of the batteries. The starter cable is connected directly to the positive terminal with the terminal edge showing in the other photo.

The other black isolator positive cable is connected to a Blue Sea Systems 300 Amp m-Series Battery Switch (black box answer), and the switch is connected to the battery positive terminal with a short red cable, quite visible in the photos.

Our coach came with a single ground cable and we added a second cable highly arched in the photo and connected to frame.

Re: New Start Batteries

Reply #14 –
Larry, I assume all U320 came with 3 batteries parallel wired, so 3 red tops will likely fit. Our 3 batteries easily fit in the OEM tray. We do have a piece of flat metal under the batteries so the batteries have a flat surface to sit on.

Yes, bus bars are aluminum. When I made them years ago, I could not find thick copper or thick aluminum, so I figured that two parallel aluminum bars from Lowe's could carry the amps for each of pos & neg.

We have long used 'military' battery terminals and before bus bars, used to have two short pairs of cables between batteries.

We long ago trashed the original OEM one-piece cables that had automotive post terminals built in because while the cables were ok, over time the terminals stretched and wore. Much easier now to quickly replace a terminal if it acts up in any way, so we recommend only using these military battery terminals with bolts to attach battery cables or in our current case, bus bars.

Re: New Start Batteries

Reply #15 –
Thanks for the info Barry. I'll be looking into it.

Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: New Start Batteries

Reply #16 –
what were the thickness and width of the aluminum bars you used? I found a website online to order custom sized aluminum bar
Jody and Juli
1997 U320 40ft. Cummins M11 400hp
Build #5028
Master Mariner Unlimited Tonnage
USNR Lt. Commander (ret)
Texas A&M Maritime (me)
Baylor (wife)
 

Re: New Start Batteries

Reply #17 –
Quote from: Ted & Karen –
When I needed to replace my 2 start batteries I went with 2 Group 31 Truck batteries, maintenance free @$110 each.  950 CCA each.
I have seen these batteries on sale as low as $80 each.  Haven't touched the boost switch since then. 

Cya down the road............................ ^.^d
Group 31 are hard to beat. I've been using three Duralast group 34 and after about 10 trouble free years, went to three Duralast 31 series. I asked Autozone for a discount for buying three and they gave me 10% so all three were about $300 total. Almost 3000 CCA now so plenty for sub-zero winter. Detroits come with three start batteries for the slightly larger engine. Have never touched the boost switch since we bought the coach back in 2008.

Battery quality usually goes hand in hand with weight. Think these were about 5 lbs heavier than some of the others I checked.

Make those bus bars out of copper not aluminum. Aluminum only conducts 61% as well as copper. Just go to a welding shop and buy the cable or buy some copper stock. In winter when you need the CCAs, the higher resistance of aluminum creates more heat. Heat raises the resistance and so on.

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