Upgrading Chassis Batteries - 2018 Cornerstone

[LWBAZ]

Thanks Chuck - good info. The Tiffin PowerGlide chassis on our Allegro Bus was one of the very last built with a pre-DEF engine, so that might explain some of the differences.

Amy & I are attending the Spartan Academy class the last week in August. Maybe they'll touch on this subject as part of the training. If not, I'll attempt to remember to ask about it.


Thanks again for your insights - much appreciated!

[18Anthem]

Originally Posted by brobox

Normal. I called Spartan when my coach was new, and was informed if it did not show discharge for about 30 seconds that I had a bad DEF heater. I live in FL where it's always 90 degrees

Thank you!

While we were on our Doctor appointment tour the past few weeks I watched the VegaTouch Battery Read out when my husband cranked.

Before turning Key On Chassis Read 13.6 volts
Turned Key (but not cranking...waiting for start) 12.9 volts
Cranking we shot down to 10.6 Volts

This is for 450 ISL 2018 Anthem 44B


Glad we know this is normal.. just worried us that we needed to replace batteries eventhough we had them checked out at our service last month.

Now on to our other questions

Daphne (and Stephen)

[LWBAZ]

Originally Posted by Matt D

Larry, did you have the old SLA batteries load tested before you recycled them?

Originally Posted by LWBAZ

Matt, I didn’t recycle the Harris batteries, I kept them for “shop” batteries. I currently have a CTEK maintenance charger on each of them, so they should be fully charged. I’ll run a load test when I have a few minutes and let you know the results.

To be clear, I didn’t have any indications the Harris batteries were bad; I just felt they were marginally adequate for cranking that big X15 engine hanging on the tail end of our chassis.

Finally found time to run some tests on the two Harris Sealed Lead Acid (SLA) chassis batteries originally installed in our 2018 Cornerstone, which was delivered in October 2017.

I first ran a Cold Cranking Amps (CCA) test on each battery using a device called a conductance tester, specifically this one:

https://www.cloreautomotive.com/sku.php?id=512

I’ve had that tester a couple of years now and find it to be useful but not precise. It’s simple to use, but if I test the same battery ten times in a row I’ll get a variety of results. What I’ve learned to do is run the test six or eight times, throw out the high and low readings, and average the rest.

In this test, Battery #1 averaged approximately 860 CCA and Battery #2 averaged about 900 CCA. Not too bad for batteries rated at 950 CCA.

The second test was a load test using a carbon pile load tester, specifically this one which I’ve had for quite some time:

Model 6034 | Associated Equipment Corp.

The idea here is to read and record the battery voltage displayed on the tester, crank up the knob to apply a load equal to about half of the battery’s CCA rating (950 CCA/2 = 475 Amps), and note how far the voltage falls off under that load. (CAUTION: Carbon pile load testers generate a lot of heat, so if you use a tester like this be careful and be sure to let the tester and its cables & clamps cool down between tests.)

In this test, both batteries were at 12.8 to 12.9 volts (full charge) before applying any load. Under load, Battery #1 fell off to 9.8 volts, while Battery #2 fell off to 9.4 volts. So Battery #1, which was the lower of the two on the CCA test, performed a bit better than Battery #2 on the load test.

Of the two tests, I’m inclined to apply more significance to the load test, but taking all the test results into account I would say both batteries “passed.” My experience with failing starting batteries has been that they not only fall off under load but their voltage usually continues to drop for the duration of the test (about 15 seconds of load), whereas a healthy starting battery will fall off to a given voltage under load and stabilize at that voltage for the duration of the test.

Bottom line, my conclusion is that the primary reason I was experiencing rather anemic engine cranking with the Harris batteries and am not experiencing it with the NorthStar batteries is that the NorthStar AGM batteries have a substantially higher CCA rating than the Harris batteries – 1150 CCA for the NorthStar batteries versus 950 CCA for the Harris batteries, an increase of approximately 21%.

[Matt D]

Thanks for the results Larry. Have you considered sharing your data with Spartan and Entegra to see if they might make an improvement for future models?

It seems like you have done a thorough job of identifying an area that needs some improvement.

-Matt

[LWBAZ]

Matt, it is my opinion that NorthStar AGM starting batteries and Lifeline AGM deep-cycle batteries are as good or better than anything currently available. Lithium batteries are a different discussion, and while I’m pretty certain they’re the wave of the future, they’re not yet in mainstream use by the RV industry. (But, it’s interesting to note that lithium batteries do have a growing presence in the golf cart industry – see https://ezgo.txtsv.com/elite.)

My opinion of NorthStar and Lifeline batteries received a bit of confirmation when Amy & I recently had the opportunity to tour the Newell Coach manufacturing plant in Miami, Oklahoma. Starting batteries – NorthStar. House batteries – Lifeline. Motorhomes – Oh yeah, I want one. Likelihood of that happening – pretty much zero, but a guy can dream can’t he?

Returning to reality and motorhomes mere mortals can kinda-sorta afford, the major chassis manufacturers (Freightliner, Spartan, Tiffin PowerGlide) all install a pair of Group 31 Sealed Lead Acid (SLA) batteries rated at 950 CCA apiece. The brands vary, but the batteries are all about the same. I got a solid five years of use out of the Interstate 31-MHD's Tiffin installed in the PowerGlide chassis under our 2010 Allegro Bus, before replacing them with NorthStars.

But those batteries were cranking a Cummins ISL engine, not an X15. As such, my opinion is that 950 CCA Group 31 SLA batteries are probably adequate for engines up to but not including the X15. It would be nice to see Spartan and other chassis manufacturers install higher capacity starting batteries on their higher end products, or at least offer the option.

Regarding house batteries, Tiffin has for some time offered 300 AmpHour Lifeline GPL-6CT AGM batteries as optional at extra cost, in place of the standard GC2 flooded-cell batteries. The last I knew, the upcharge was $2,240 list for six batteries, which translates to $1,680 or less after the usual discounting. That computes to less than $300 per battery, which is pretty reasonable for GPL-6CT’s.

Entegra takes a different approach, installing L16 AGM batteries as standard equipment, but they go with less expensive brands like Discover. I’m not sure how many owners would bite, but I’d like to see Entegra offer an option for Lifeline L16’s and would be willing to pay extra to have them.

[2Nailz]

Originally Posted by LWBAZ

Thanks Chuck, good info.

My frame of reference was our previous Tiffin Allegro Bus which was built on a Tiffin PowerGlide chassis. It was definitely set up to only activate the inlet air heater at lower ambient temperatures. After having the problem where the activating solenoid stuck in the on position, I added an indicator light in the engine compartment that would illuminate anytime the inlet air heater was on.

Watching that light, I confirmed the heater only came on in cold weather but also learned something else of interest, which was that when the heater was active it wasn't continuous. Instead, it would come on for ten or fifteen seconds, turn off for a similar period of time, and continue that pattern until the engine warmed up a bit. Not sure if other chassis manufacturers do the same, but that's the way it worked on the PowerGlide chassis.

It seems strange that Spartan would have the inlet air heater come on at startup regardless of ambient temperature. Maybe because where they're located it never gets all that warm...?

I wonder if this is what I notice after starting my ISL9 450. The volts gauge fluctuates from approximately 12 to between 12 and 15. It does this approximately 4-6 times before settling between 12-15 and staying steady. Could this be an indicator of the engine inlet air heater cycling?

[757driver]

Originally Posted by 2Nailz

I wonder if this is what I notice after starting my ISL9 450. The volts gauge fluctuates from approximately 12 to between 12 and 15. It does this approximately 4-6 times before settling between 12-15 and staying steady. Could this be an indicator of the engine inlet air heater cycling?

That is exactly what you are seeing.

[2Nailz]

Originally Posted by 757driver

That is exactly what you are seeing.

Thank you! Another mystery solved!

[Mr_D]

My ISX 650 has 4 - 925 CCA starting batteries. Even with that it struggles to turn over.

[2Nailz]

You might consider these from Batteries +. Looks like they are made by NorthStar, come with a 48 mo. warranty, and are a little cheaper.

https://www.batteriesplus.com/batter...1m/sli31agmdpm

[LWBAZ]

Curtis, that is indeed a NorthStar battery. The only issue I see with that particular model is that it has both threaded posts and the fatter SAE posts. The Group 31 starting batteries in our coaches have threaded posts only and the cable are such that if an owner tried to install a dual post battery the existing cables might or might not work.

The battery in your photo is the equivalent of a NorthStar NSB-AGM31M. NorthStar makes two other Group 31 batteries, the threaded-post-only NSB-AGM31 and the SAE-post-only NSB-AGM31A.

I suspect Batteries Plus carries or can get the “X2 Power” Group 31 batteries in a threaded-post-only configuration and that is what I’d be asking for if I wanted to buy from them.

[2Nailz]

Good call Larry. I haven't decided to get new batteries yet, but you make a great point about the double posts. Batteries+ is local, so I suppose one could check it out and if it didn't work return them.