Time to replace battery? Upgrade to AGM?

[AZjeff]

I just did a 200 mile highway trip yesterday in the 2021 GMC with the 6.6 gas engine (empty) and decided to check the resting voltage of the battery this morning and it's 12.54 volts. The truck is used to tow the travel trailer all over the country and I don't want to deal with a no-start - replace battery deal out in a remote campground somewhere. The battery is original and is a group 94, 720 CCA and GMC lists a 94 and a 48 as replacements. I have a decent Klein multimeter and tested directly from the terminals so that's a good number. Also would an AGM equivalent like an H6 be a good upgrade? My standard SOP with batteries has been replace it when the first slow crank is noticed but maybe not in this useage. I've been following the ongoing "no more AGM" thread and as usual varying thoughts about AGM vs flooded.

So, replace almost 5 YO battery now and go to AGM or replace with another flooded L/A?

 

[cptbarkey]

12.54 isnt dead yet.

I'm buying only AGMs the past few years, even for my riding mowers and UTVs.

 

[D60]

If it were me, I'd probably get the biggest baddest flooded I could through your favorite corporate FLAPS with easy warranty, and forget about it.

I'm not convinced AGM is not a bit more fragile, and they still tend to be a bit more $

 

[hemitom]

Still life in it !
I would get it load tested before replacing .

 

[SC Maintenance]

Invest in one of those cheap testers. They come on sale at Amazon for like $20 here and there and work surprisingly well.

I agree - 12.54 V doesn't sound dead. Voltage can vary by battery - no two are identical.

With your heat I would likely go AGM - I did in mine, so far so good.

 

[diesellover]

12.54 resting/ open circuit voltage isn't bad. What would be best is an overnight trickle charge between 1 and 4 amps. The slow top off of any battery helps break off buildup off the plates, and other positives. A slow charge is good for batteries as an alternator does not charge the best. I worked for a large truck leasing company, part of any truck inspection was connecting an associated battery charger and charging the batteries that way.

A load test will be best after this. Although 12.66 volts is a fully charged battery in good condition (2.11 volts per cell, and there are 6 cells inside a battery) anything under 12.4 volts is technically a dead battery. Much like anything below 80 % on a 32 PSI tire (below 26psi) would be technically a flat tire).

 

[diesellover]

Keep in mind, some alternators don't like charging agm batteries properly. They require a slightly different charging cycle although I'm not an expert. Not all agm batteries are the same. Odyssey batteries were the worst agm batteries I've ever seen in the trucking industry, but most other agm batteries do pretty well FWIW.

 

[AZjeff]

favorite corporate FLAPS

??

 

[Nukeman7]

??

Friendly Local Auto Parts Store

 

[fozzdesy2001]

NAPA Legend gets it done

 

[fantastic]

AGM probably worth the extra cost but your voltage reading still measures good. Maybe run it until your weather starts getting real hot then switch to AGM? Will that coincide with your trip timing? Buy one of those lithium battery starters to keep onboard anyways?

 

[AZjeff]

NAPA Legend gets it done

Yesterday I took a different battery to the FLN(NAPA)APS to have it tested and was told their battery tester was broken and the counter guy didn't offer when it would be fixed or replaced. And NAPA is the only place I feel like they kinda know some things.

 

[D1dad]

I’m not sure how the charging system works on that truck, whether it’s charges to optimize mpg. I’d assume with that guzzler that they’re trying to squeeze anything they could get from it. That would dictate my decision if I went flooded or AGM.

 

[GMBoy]

Use the recommended battery. The charging system is designed around the OEM battery type. I don't agree with upgrading to AGM "just because" if it came spec'd for lead acid.

 

[DCDG]

I just did a 200 mile highway trip yesterday in the 2021 GMC with the 6.6 gas engine (empty) and decided to check the resting voltage of the battery this morning and it's 12.54 volts. The truck is used to tow the travel trailer all over the country and I don't want to deal with a no-start - replace battery deal out in a remote campground somewhere. The battery is original and is a group 94, 720 CCA and GMC lists a 94 and a 48 as replacements. I have a decent Klein multimeter and tested directly from the terminals so that's a good number. Also would an AGM equivalent like an H6 be a good upgrade? My standard SOP with batteries has been replace it when the first slow crank is noticed but maybe not in this useage. I've been following the ongoing "no more AGM" thread and as usual varying thoughts about AGM vs flooded.

So, replace almost 5 YO battery now and go to AGM or replace with another flooded L/A?

I used a multimeter for years to check car batteries. Get yourself a dedicated automotive battery tester a multimeter will tell you voltage but not what's actually going on inside the battery. I would recommend this tester https://www.amazon.com/dp/B01M0ARG3X?ref=ppx_yo2ov_dt_b_fed_asin_title

 

[Fabulous50s]

AGM really isnt an upgrade for general automotive use, and wont charge properly.

AGMs do well in high vibration applications like OPE, powersports etc.

The largest group size in the lowest CCA will last the longest. Higher CAA in a smaller package puts the plates closer together with thinner plates making the battery more fragile and less tolerant to sulfate making for a shorter life.

Ive had several low CCA batteries last over 8 years in automotive applications in my vehicles and we experience several days of -30F every winter and vehicles stay outside.

 

[GMBoy]

AGM really isnt an upgrade for general automotive use, and wont charge properly.

AGMs do well in high vibration applications like OPE, powersports etc.

The largest group size in the lowest CCA will last the longest. Higher CAA in a smaller package puts the plates closer together with thinner plates making the battery more fragile and less tolerant to sulfate making for a shorter life.

Ive had several low CCA batteries last over 8 years in automotive applications in my vehicles and we experience several days of -30F every winter and vehicles stay outside.

True! I learned this as a teen when I was going thru a battery every year on my lifted Jeep CJ7 (read rough ride lol). I would always buy the most powerful battery I could (1000cca) and they lasted a year. Finally, after the 3rd battery and under a friend's advice, I got a standard 600cca amp battery - sucker lasted 4yrs!

 

[mva]

The resting voltage depends on the battery temperature. If it was cold when you checked it 12.54 volts could be normal for a fully charged, healthy, lead acid battery.

Here is one chart I found:

 

[Fabulous50s]

Ive got a cheap JCI made Ever Srart that came in a vehicle I bought. It is 550 CCA group 36 i believe and 10 years old this year. Still starts, but is likely to be replaced this summer. Longest ive ever had a car battery last. Ive had the best luck with cheap low CCA batteries like what the OEMs used to use.

Years ago the shop i worked at sold Interstate batteries and the rep told me about longevity vs CCA/power density. Internally shorted batteries are due to plates touching from vibration and sulfate causing a low resistance connections.

 

[oilstudent24]

The resting voltage depends on the battery temperature. If it was cold when you checked it 12.54 volts could be normal for a fully charged, healthy, lead acid battery.

Here is one chart I

And it also depends on if the computers were asleep on what voltage it reads.