Battery question- group 31, H7, 9A94R???

[CMB]

Well, still working on the "No Bus" situation. The dealer gave me the run around so before I pay the deductable I'm looking into a few things my self. A few months ago a had some battery trouble. I pulled them- charged- replaced and all seamed to be well. Now I see my guage is reading low even though they read 12.4 with a meter. Bottom line is I'm going to replace them. I'm not looking to start a battery brand war just looking for the right group size. I still have the factor battery blankets on both and would like to retain them. All my searches turn up a multitude of answers. I believe the H7 is the factory group but some recommend going to a group 31. Others mentioned 94R. I'm attempting to look up each group to compare the size and specs but it's taking quite some time. If anyone can share some insight on this it will be greatly appreciated. This is on a 2012. I do run a few accessories so if there is a deep cycle with the correct cranking rating that will help. I was leaning toward Costco Interstate or Deka. Thanks again All.

 

[randygk]

Just replaced mine , started getting random error messages when starting. I went with Interstate MTX-94/H7 AGM. The blankets fit properly and exact replacement battery, yours might be a different part number(different year). Noticeable difference in starting.

 

[Mike Wenrich]

I was in Costco recently getting new Michelins and while waiting looked at the battery selection for my 2014. Seems I recall their book saying the group 31 is the correct replacement battery. Could be wrong but I also noticed whatever it was, it's BIG. I feel a hernia coming on or maybe I will just have them replace them when the time comes.

 

[CMB]

I measured the battery that's in the truck currently. It measures 12 1/4 x 6 7/8 x 6 1/2 that's L x W x H. The MTX-94 looks like a great option. Randy, I'm assuming the error message was before you changed the battery right? Costco is recommending the H7 (their code 30) which is the same as the 94R. I wonder if they have the MTX? Thanks for the feed back. It's good to have a reality check.

 

[TFucili]

I am a Deka fan. I just went with O'Reilly Platinum 94R, which are Deka AGM. I left the blanket off, as I had a leaky OEM battery, and could not see it with the blanket in place. Lots of baking soda and rinsing. Looked like the plastic tray contained it.

 

[jhenderson]

I just put a set of Deka 94r agm batteries in my 15. The originals went just over 100K. Voltage tests showed both ok but a load test said different. One was still good but the pass side had a bad cell.

 

[JR]

Group 31 is not oem size but if you can make it fit I'd go for it. I just had a nearly brand new 31P MHD given to me, my truck batteries are a mismatch so when I get some time in the next few weeks I'm going to see if it will fit. If it does, I will be buying another 31 and installing both. Measuring my batts in the truck, the 31 looks to be a heavy 1/4" longer and slightly taller. They should fit. Advantage - these are 950 CCA batteries at roughly the same price. The long term benefit in cold weather starting is less strain on the batteries and quicker recovery.
But you may have hard time with cores being you would be buying a different battery. I plan on keeping my truck batteries anyway. They'd be an upgrade in some of the stuff I have around here.

 

[CMB]

Ok - things are still a little off. I replaced the batteries with interstates from Costco. I was surprised to find that the drivers side battery tray does not have a drain. There are nifty little channels for moisture to run though but they lead to a cavity so the water just sits there. I thought about drilling a hole, maybe 1/4 inch or so but didn't at this time. Besides, water in this area should be minimal.

Can anyone tell me what the battery gauge actually measures? It's reading just above the "8", not quite to the line between the 8 and the 14. Presumably that line is 12. I would figure when I turn the key on it should be at or near the 12 line than jump to the 14 line when running. Is that a fair assumption? As stated, mine stays between the 8 and the next line. I do have a USB charger with a voltage display that reads 12 - 14 volts. What could cause the guage on the dash to read low? The gauge cluster was just replaced by the dealer due to lamps being out. Thanks in advance for any and all suggestions on this.

 

[TCDiesel]

The instrument/Dash Module May need to be re-flashed. They do read about- .25-.75 lower than actual, Yours is Way off. It takes some time to move up after starting 30-60 seconds. The battery sensor module checks the condition of both batteries on 2013+ I would need to look into 2012- to comment on that year.

 

[TCDiesel]

2012 does have self checker software

08 - Electrical/8F - Engine Systems/Battery System/Technical Specifications
SPECIFICATIONS
The battery Group Size number, the Cold Cranking Amperage (CCA) rating, and the Reserve Capacity (RC) rating or Ampere-Hours (Ah) rating can be found on the original equipment battery label. Be certain that a replacement battery has the correct Group Size number, as well as CCA, and RC or Ah ratings that equal or exceed the original equipment specification for the vehicle being serviced. Battery sizes and ratings are discussed in more detail below.

• Group Size - The outside dimensions and terminal placement of the battery conform to standards established by the Battery Council International (BCI). Each battery is assigned a BCI Group Size number to help identify a correctly-sized replacement.
• Cold Cranking Amperage - The Cold Cranking Amperage (CCA) rating specifies how much current (in amperes) the battery can deliver for 30 seconds at -18°C (0°F). Terminal voltage must not fall below 7.2 volts during or after the 30 second discharge period. The CCA required is generally higher as engine displacement increases, depending also upon the starter current draw requirements.
• Reserve Capacity - The Reserve Capacity (RC) rating specifies the time (in minutes) it takes for battery terminal voltage to fall below 10.5 volts, at a discharge rate of 25 amperes. RC is determined with the battery fully-charged at 26.7°C (80°F). This rating estimates how long the battery might last after a charging system failure, under minimum electrical load.
• Ampere-Hours - The Ampere-Hours (Ah) rating specifies the current (in amperes) that a battery can deliver steadily for twenty hours, with the voltage in the battery not falling below 10.5 volts. This rating is also sometimes identified as the 20-hour discharge rating.
• Load Test Amperage - The Load Test Amperage rating specifies the current (in amperes) that a battery should be tested at with the battery load test equipment. This value should always be 50 percent of the CCA. For example: if the CCA for this battery is 600 amps, the Load Test Amperage is 50 percent of that or 300 amps.

The PCM (Powertrain Control Module) monitors the critical input and output circuits of the charging system, making sure they are operational. A Diagnostic Trouble Code (DTC) is assigned to each input and output circuit monitored by the On-Board Diagnostic (OBD) system. Some charging system circuits are checked continuously, and some are checked only under certain conditions

 

[CMB]

Sorry for the glares but the point still remains. This image is while the truck is running (obviously).

Thanks again for the feed back.

 

[CMB]

Where it reads while off. Well, back to the dealer. ... yuck

 

[Mike Wenrich]

Question. Can you check both batteries for voltage with the cables attached? Or do you get feed from both and you need to disconnect cables from the batteries to get an individual read?

 

[TCDiesel]

NO, they need to be separated.

 

[12LaramieHO]

CMB
I find it hard to believe that after replacing 2 batteries with new ones the volt meter would be reading that low, even with an error in the gage with the engine running. There's something else going on there.
Prior to replacing both my batteries when they were weak, once the CTD fired, the volt meter would recover fairly quickly to beyond 12 volts.
I think I would look at the charging system, alternator output etc.
Good luck at the dealer.

 

[lpennock]

Check the small cable from driver positive to TIPM. Had corrosion on mine that caused low charge indications.