Lifeline AGM and extreme temperatures?

According to the lifeline manual they can be stored fully charged anywhere from -67f (-55c) to 122f (50c) They can be used in temperatures from -40 f&c to 160f (71c)

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If Lifelines last years and years at underhood temperatures in ambulances at vehicle charging system voltages, then what say you to veritable battery paradise temperature and voltage wise?

The AGM temperature/voltage "kick" has gotten entirely out-of-hand on this forum. LIFELINES ARE LESS TEMPERATURE SENSITIVE THAN 5% ANTIMONY BATTERIES! I did not say VOLTAGE SENSITIVE. Imagine what happens to an AGM in Phoenix in July, underhood on a 120 degree summer afternoon. Yeah it's not going to live as long as a laboratory maintained AGM on float. But such a comparison twisted so make it sound as if the AGM is doomed, is worse than foolish.

Understand it clearly. Corcorde wants to brag it's expensive batteries have phenomenal lifespans. I tried to make float voltage maintenance have meaning on this forum by raising SG to maximum then reducing float voltage to absolute minimum to reduce maintenance current to next to nothing without having specific gravity start to slup. Lifeline, being perfectionists try to impress this philosophy upon customers without explaining PRECISELY how their philosophy fits into the overall scheme of reality. Their meticulous attention to detail just tickles me but the buying public adopts meticulous recommendations as gospel. Do not forget the same people who issue Mil-Spec bulletins and qualifications also construct user manuals for the public. Concorde demands their customers toe the line right to the millimeter. Other AGM companies have adopted a looser than a goose user manual. A German pre-war hunter's manual is a good parallel. It demands the shooter take an almost fencing grade degree of posture placing the feet, hands and fingers, just so. Remember, the game could care less, but etiquette demands it without compromise.

BuShips battery maintenance manuals for US submarines is similar. You would not believe the intense, rigorous level of goose-step grade maintenance and daily testing and proofing. Boats had to return to Mare Island to exchange batteries and the military demanded the crew baby those batteries as if their life depended on it.

This is definitely not an endorsement of going to extremes and getting sloppy with charging control - it is a reality check in which manufacturers of a premium priced product worry about images and perceptions. AGM manufacturing is not a lucrative profit endeavor, sorry, edeavour. Cost of materials, construction, and testing is pricey and profit percentage is around 150% that of a standard premium flooded battery. Remember base prices start at a higher figure. The quantitative production numbers are tiny compared to flooded batteries.

But skipping the purchase of an AGM brand because of a two-tenths of a volt disagreement between set maintenance charging voltage value and OEM battery recommendation, is just plain silly.

They are more temperature resistant than flooded--but for longest life make sure any charger uses temperature compensation.

Three 8D's are going to make your rig an AmeriHeavy.

True. Luckily it has a 3000 lb CCC.

Don, I bought the TS-MPPT-60 because of that and other features.

Temp compensation is the hot setup. But conscientious manual setting is even better. After I bring my empty coffee back in, after screaming at garden vegetation to grow faster, I fine tune float settings. Time consuming - must take 4-seconds.

Mex wrote:
But skipping the purchase of an AGM brand because of a two-tenths of a volt disagreement between set maintenance charging voltage value and OEM battery recommendation, is just plain silly.

Now .... if one could just get the OEMs to agree that their published maintenace voltage values are silly if ever a warranty replacement becomes an issue between an OEM and a user.

BTW, if it's OK for all AGM batteries to use the same float voltage irrespective of electro-chemistry and construction .... I wonder why some AGM batteries off the charger sit week after week holding 13.1 volts on their terminals after being fully charged, while other AGM batteries off the charger sit week after week holding 12.8 volts on their terminals after being fully charged?

I have personnally seen this AGM terminal voltage difference during long-term non-use in my various AGM batteries in equipment, pickup trucks, boats, and RVs. The times have been too long, in my experience, for the differences to be due to surface charge bleed-off times.

It's hard to believe that all lead acid AGM batteries should act, and be treated, the same ... terminal-voltage-wise ... regardless of what combinations of materials and chemistry were used in their manufacture.

So far I'm willing to believe that this goes for float voltage differences, too. IMHO ... Lifeline, Fullriver, C&D Technologies, Rolls Surrette, etc. may agree with this, too.

I have seen flooded batteries do it too. It may dawn on you this is a QUALITY issue not a chemistry distinction. Self discharge SHOULD therefore be highest in AGM batteries with the lowest impedance - right? Sorry. Wrong. A battery has fully capable tendencies to eat itself if constructed wrong. An AGM that has a high static discharge is inferior. But just because the battery may hold high static voltage is not a guarantee of good quality. Some fall head-over heels for hyperbole and overly fussy technical recommendations. It's a free decision to manage personal property according to choice. Just remember those thousands of AGM batteries basking in underhood temperatures at voltage values far in excess of float recommendations. Do you see skull and crossbone symbols NOT FOR AUTOMOTIVE USE?

MEX wrote:
Do you see skull and crossbone symbols NOT FOR AUTOMOTIVE USE?

Nope ... but I don't see starting batteries under hoods lasting 9-10 years either ... like many deep cycle batteries floated properly in RVs do. ;)

So, what's your take on a Lifeline guy on the phone telling me that their batteries would dry out prematurely if I floated them at 13.6 volts year after year like I did my Interstate (C&D Technologies) AGM RV batteries for ~ 8 1/2 years?

MEX wrote:
But just because the battery may hold high static voltage is not a guarantee of good quality.

Hmm ... I thought a poster recently mentioned a Lifeline AGM sitting at about 13.1 volts terminal voltage after resting awhile after a full charge? (My memory could be wrong on this, however.)

My Group 31 95 amp hour yellow top cylindrical Optima AGM sits at about 13.1 volts for weeks after a full charge. My Interstate AGMs sat at about 12.8 volts for weeks after a full charge. My new Fullriver AGMs look like they're going to sit at about 12.8 volts after a full charge.

What can be the cause of this ~0.3 volt static voltage difference?