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Battery advice

Been high of 30 low in the teens for a week.
This is the gv320 unit from Austin that sat for  5 yrs, overall I've been very satisfied with it and we have been busy sprucing it up. Just purchased unit in January and they had replaced the starting batteries with 3 cheap Autozone 660 cranking amps. It has always seemed like a hard to start, slow start like batteries didn't have enough umpff  and I know they let the unit sit and the batteries run down several times according to post on this site. I've kept it plugged in and start batteries on a maintenance charge.  Would not start in 30 degree weather.  Had the block heater, aqua hot engine heat and boost switch on overnight.  Changed charger to full charge and left all the above on again overnight and the engine started this morning.

I assume it's time to replace and take better care of the batteries.  Doing some research on the site seems like group 31 yellow top are OME 900 cold cranking amps, is that correct?  I am not a full timer and don't have any solar and probably won't be a boondocker for more than 1or 2 nights, do you recommend puting in the yellow top, is it worth it or just a 900cca maintenance free truck battery that I could afford to replace 2.5x. And if so what truck battery do you recommend, or which post do you recommend reading. I'm looking for opinions

Thanks for your time

Re: Battery advice

Reply #1 –
Cranking AMPS are a little low.. but before you do the change the batteries. Check all connections at the battery and the starter and make sure they are clean and tight.

THought the motor needed 2k in CCAMPS? could be wrong

Re: Battery advice

Reply #2 –
I am using Red-Tops with an Optima charger on inside the coach and run the wires under the bed to the batteries. 5 years never a problem. Mounted under the bed skirt on the bed sidewall. 
John

Re: Battery advice

Reply #3 –
You might want to check and see how many Amps the starter is drawing. It may be getting old and drawing too much.
Someone will know how much is normal.
If can't start at all, start generator and run for few minutes with batteries bridged, then try and start.

Re: Battery advice

Reply #4 –
The thing about lead acid batteries of any type is that they loose capacity with age.  If it was 600 cca new, it may only be 400 cca after a few years..  The voltage may show normal up until it dies.  Most of the auto parts stores will test your batteries free of charge.  Your can either remove the batteries or take the coach to their location, if there is room to park.  Have the batteries fully charged before testing.  You may have to disconnect some cables for the test.  Another thing to consider is what type of house batteries do you have.  It is best to have the same type chassis and house batteries, so that the inverter/charger can be set for that type, although the charging should be set for the type of house batteries even if the chassis is different..  Unless the boost switch is on, the inverter/charger only charges the house batteries.  The boost switch consumes some power from the house batteries when on.  Some owners have installed a trickle charger for the chassis batteries to keep them topped up when plugged into shore power and parked for long periods.  I disconnect the chassis batteries when in storage for more than a week as there is a small drain even if everything is off.

Re: Battery advice

Reply #5 –
Auto Zone batteries are not that bad,if there too small it's not the batteries fault,you should have one of the "pulse" chargers and
try and get the batteries back to specs,check the connections like the above suggests.

Re: Battery advice

Reply #6 –
Truck/high amp hr start batteries are just fine.

Freightliner often runs specials on their start batteries.

http://images.ebizautos.com/sites/12153/pages/USA_PARTS_PRINT_JF2019.pdf?_ga=2.167027902.1664034545.1552146333-1218270953.1552146333

Depending on your battery tray size, options at Sams Club:
http://www.samsclub.com/sams/duracell-automotive-battery-group-size-34/prod3590251.ip?xid=plp_product_1_15

http://www.samsclub.com/sams/duracell-commercial-battery-group-size-31c/prod3590235.ip?xid=plp_product_1_18

Re: Battery advice

Reply #7 –
Most 320's came with optima red tops, 800 CCA each.  Engine requires 2,000 as was posted.

Lots of more than ten year life's posted here with the red tops.  The key is to never deep discharge them.

A single deep discharge can damage any non gel battery,

Somewhat restorable with a pulse desulfurization system 

To prevent this i and later Foretravels and the rv business installed a battery bank auto combiner,

 Blue sea 500 amp works great,

No separate engine battery bank charger needed anymore.





Re: Battery advice

Reply #8 –
No reason to spend high dollars on batteries that don't last any longer than Autozone Duralasts. Our 24 series lasted about 10 years and our new Duralast 31 series have 2800 CCA and cost $300 for all three. Ask for discount when buying three as it saves about 10 percent.

Search and read reviews before throwing $$$ away.

Pierce

Re: Battery advice

Reply #9 –
The engine compartment location subjects the later  U series unicoaches to much more vibrations than the inherently smoother v engines used in the Unihomes,

The higher torque rated in line six cylinder engines need the strongest burst of power from their start batteries. 

The batteries location in the hot engine compartment adds a additional burden on the batteries design. This is from the redtops page. 

KEY BENEFITS
Strongest starting burst
Up to 3X longer life
15 times more vibration-resistant
Virtually spill proof
Mountable in virtually any position
Maintenance-free
Faster recharging
Optimal starting power

The stereo kids use a second red top and a capacitor to allow heavy base speaker use.  Quicker burst of power required for the base.

My alternator dash needle used to move with a fancy stereo in response to the musics heavy beat.



Re: Battery advice

Reply #10 –
Bob,

No, straight 6 diesels are smoother than V-8 diesels (or gas). While the longer crankshaft does limit RPM in comparison to a V8 it generates much less secondary vibration.

The smooth V engine you speak of in a Unihome is the 2 cycle Detroit 6V-92TA with each cylinder firing on each revolution plus no secondary exhaust stroke vibration. The 2 cycles V sixes are glass smooth but the straight 6-71 Detroit was the smoothest of all engines. The 3208 V8 CATs or Detroit 4 cycle 8.2L V8s have the same V configuration balance issues.

See the I-6 vs V-8 comparison at: Inline 6 vs V-8 Diesels

As far as batteries go, I never believe what manufactures advertise but read user reviews to evaluate the product. This goes for anything.

Pierce



Re: Battery advice

Reply #11 –
Off the topic, in-line engines, diesel in a truck or motor home , produce more torque at low RPM. Much better for starting out with a heavy load . V engines produce their horsepower at high RPM..we use torque in motor home, the higher the torque, the easier to pull the load. So when looking for a motor home we say " I love it 550 Hp, what we are really loving is the fact the torque rating is higher. If you ever drive an old diesel V8, you will find it has a very narrow RPM range.. as a result you shift a lot of gears in a day !!!

Safe travels,
Dave

Re: Battery advice

Reply #12 –
Even when plugged in with battery charger keeping house batteries under a charge, there may be no charge on start batteries, causing them to run down over time.

Measure battery bank voltage to determine if that is the main problem.

No reason to change batteries when the problem is they are not being charged.

Re: Battery advice

Reply #13 –
I may not have made it clear in the 1st post but I did have a maintenance charge on the starting batteries and switched it to a full charge and it still took 36hrs before it would finally start. I also had the coach plugged into 30amp at my house. I will take clean contacts and take it to autozone to test batteries and hopefully they can test the starter too.

Thanks for all your help

Re: Battery advice

Reply #14 –
I replaced my 3 red tops years ago with COSTCO (Interstate) wet cells. Never a problem.
With the COSTCO warranty I will probably never have to pay again for batteries. With about 3000 cold cranking amps even if they diminish there is still plenty of head room on the starting ability and for the cost compared to the Red Tops I could replace them twice and still be money ahead.
Batteries are a disposable item, I treat them as such.

Re: Battery advice

Reply #15 –
Being sort of a prepper and a remote drycamper a shorted cell in any flooded cell battery is a non starter.  No pun intended.

It happened to us long ago.  And the old diesel coaches two house batteries which were down on SOC. Would not winter start the coach.

Lucky that the country coach long ago we were using had a separate gen battery which got the gen going then the house side charged up then we could boost over the bad battery and start the motor.  Belt and suspenders stuff. 

Too cold to go out and play with battery cabling.

This was today after not touching the coach for four weeks in dry storage on 14 amps of solar and a auto combiner.

Started the engine and the start relay being energized auto disconnected the battery banks.

Engine redtops showed 9.9 volts on the lower dash gauge during cranking.

As soon as the starter relay quit receiving a input the auto connect reconnected the battery banks and went 13.88 volts

M11 vibrates a lot and the compartment gets hot.

Re: Battery advice

Reply #16 –
Bob,

I'm assuming you have the  CELECT or  CELECT plus electronic engine. Your M11 should idle smoothly, if not, use a reader/programmer to test the injectors. If they are all close, improper valve clearance can cause a rough idle. Idle setting too low to avoid stoplight creep can also cause vibration. Dirty injectors with a poor spray pattern can also cause a rough idle and slow starting in freezing weather. Additives in the fuel (tank below one quarter) may improve the pattern.

Intermittent fault in the injector wiring may also cause a rough idle even without a code. A NOID light can help diagnose any problem. A chronic short (or intermittent ECU bad ground) in the injector wiring can also fry the ECU.

If none of the above, how about engine mounts? OK?

Pierce

Re: Battery advice

Reply #17 –
Thanks for the info

I  posted a general comment about vibes.  My m11 has had the rack run and everything checked. Had a bad cam position sensor that has been upgraded to the newer design. That caused an slightly erratic idle six years ago.

I build off road racing four stroke engines.  Blueprinted balanced a lot of engines

659 cu inches of inline high compression diesel can be felt running.

My Lexus v8's can balance a quarter on it running and it does not fall over.

Different levels of harmonic vibes occur. 

Lots of variously caused vibes in the coach in general. 

Off road racers use the red tops for races. 

 

Re: Battery advice

Reply #18 –
This one seems to be going a whole different route,all the guy asked is what battery do we recommend.
To the above question,never read or heard of anyone on the forum changing engine mounts,I think it would be a good idea
to replace them if your coach is from the 90's.To properly check them you have to remove and inspect not just poke it and say it's good and if you do that you might as well put new ones in.

Re: Battery advice

Reply #19 –
Quote from: Caflashbob –
Most 320's came with optima red tops, 800 CCA each.  Engine requires 2,000 as was posted.
. . .

A single deep discharge can damage any non gel battery,

I have a different opinion here Caflashbob.  The aging of a starting lighting and ignition battery is mechanical. As you discharge the battery the lead oxides change size, causing the plate separators to move from one side to the other.  Some of the lead oxide flakes out and settles to the bottom of the cell(s).  I'm not too sure a gel cell battery will prevent this from happening.

That being said installing a BIRD, a bi-directional relay disconnect, will keep the chassis battery up to snuff while preventing the chassis  batteries from discharging with the house batteries.

The key to getting long life from SLI chassis batteries IMNSHO is regular watering with distilled water and never allowing them to be deeply discharged.