??? Set Points For Different Battery Types

[xyzHollyxyz]

I'm just learning, with a smidgen of comprehension thrown in, set points for charging batteries.

Are the set points the same for ALL AGM batteries, for ALL FLOODED/WET batteries, for ALL GEL batteries?

Meaning, are the set points different between the types of batteries, but the same among the same type?

Or might the set points be different for 2 different brands of AGM Group 27?

I am re-reading this and I hope the question makes sense. Haha.

[MEXICOWANDERER]

Like the doctor says

No salt, no cholesterol, non-fat, no-sugar, no preservatives, no tanning, minimum fiber allowance, no GMO's, no milk with cow hormones, no antibiotic laden chicken, rare steak risks e-coli, charbroiled steak risks cancer, swallow this, take that, avoid almost everything and vitamin c intake less than eqvt of eating 83 oranges daily is deadly - buy our mega doses of Vitamin C. inhaling super-heated destructive distillates of tobacco is fatal but inhaling destructive distillates of marijuana poses no risk at all.

Humanity did not listen and went extinct 2,0000,00,000 years ago.

[pianotuna]

Pnichols,

I'll gladly take those blue boxes off your hands. I promise to give them a good home. LOL

[pnichols]

Mex ..... dang, I guess that I should have taken a chance and ignored the LifeLine float spec and what their rep said.

Now I'm stuck with a couple of blue battery cases from across the Pacific.

[MEXICOWANDERER]

"Thrive" ?

"Do Harm" ?

Is the text of my writing above invisible?

When Lifeline wrote the SPECS for their absorbed glass mat batteries they constructed ONE (that means unique) charge protocol. That PROTOCOL is designed for MILITARY SPECIFICATIONS. Few individuals have the faintest conception of the meaning of the phrase MIL-SPEC. it is not only hard copy traceability of raw materials, construction, finished materials, assembly line members, verification of test parameters and equipment accuracy, but a cast in concrete GUARANTEE of lifespan. MIL-SPEC puts a manufacturer on "the spot". They cannot BS or Bluster their way out of non compliance.

Absorbed Glass Mat battery sales is a cut throat industry. As such OEM demands customers do everything but stand on their head to make their product look as good as possible.

Theoretically IDEAL environments meet that goal. Theory and Reality are not synonyms. So REALITY goals have to be focused on and judged whether or not reality and idealism can have a happy interface. Still with me?

Battery engineers have to publish "something" that pleases management or they find a pink slip sitting atop their desk. Management is psychotic about any "official" inference that makes their product look anything less than THEORETICALLY perfect. Still there?

"Uhh Harold, tell me WHY you had the audacity to publish public literature that OK'd a battery management technique that exceeded our optimum "X" float maintenance voltage value? You told me specifically that (13.25 volts) was optimum, yet you went ahead and declared (13.6 volts) as being 'within acceptable limits'. Did you lie to me when you at first declared 13.6 volts float maintenance would reduce overall battery life on average by two to three percent?"

The question is time, amplitude relative. Positive plate erosion is the single, solitary issue with this point.

Are you, the customer, willing to stand on your head, to gain 2-3% more battery life?

Drop your complaints about temperature compensation. Temperature compensation is vital but it is totally moot here, because this issue is about BASE voltage application, not temperature which as mentioned is vital.

This old engineer is too cagey to fall for Techno-Porn. Delta T thermal loss (That's BTU's) weight loss, in conjunction with E and I calculations tell the entire story.

This is FAR BEYOND what the average consumer wants to get involved with. So is the heavily insulated 14" X 6" X 9" box I constructed to measure Delta T thermal gain with the DUT. Energy is never lost - the fundamental of physics. It is translatable. Weight loss, BTU emission, in concert with voltage and current interpretation is not now, never was, and never will be a arguable point.

No a 97% lifespan is not maximum "thrive". Only a fool would claim otherwise. The question is 'Is Thrive Relevant"?

Thirteen point six volts maintenance will abruptly destroy an AGM battery at -30c and will similarly destroy an AGM battery at 60c.

You wonder about why I wax eloquent about .105" plates. Now you know the positive plate erosion factor associated with elevated float voltages.

If you want genuine hocus-pocus, visit health and nutrition websites where they have refined the art of snake-oil exaggeration to the point of incomprehensibility.

If AGM batteries were as fragile as a Hungarian actress' ego, tens of thousands of underhood AGM batteries would have bitten the dust.

SEARCH SEARCH SEARCH

Search for the AGM manufacturer who advises to not purchase their product for underhood use. Try and find an automobile that does not have Death Valley Dottie grade battery environment, and alternator voltage regulation that comes within LIGHT YEARS of VITAL AGM battery recommendations.

I fought battery hocus-pocus for 30 some odd years. I never lost a confrontation but I caused a lot of red faces and hard feelings. Car batteries are warrantied longer than flooded RV batteries. Do you see a warranty difference between automotive and other usages?

Tough

That's Reality

[MrWizard]

Mexi
i agreed with your statements
i forget was your battery connected continuously 24/7
i do know you have mentioned power failures a lot and assume that battery is NOT always connected and has had use and cycle time

BUT 'FLOAT' implies continuous voltage applied 24/7 until taken out of service or power disconnected
this does not happen in automotive
it does happen to rv and marine when connected to shore power
a boat at least sets in the water, does it get 100+ ambient temps on the water ?
an RV in the sun, can easily exceed 100+

YES plate erosion, out gas ?

[westend]

I have two banks of batteries in storage. One bank is 2 x 6V GC2. The other bank is three AGM batteries, totalling 100 AH. The banks are currently connected in parallel to a solar charge controller that is temperature compensated. The charge controller briefly goes into absorption mode in the morning (14.8 V) and then maintains a float voltage of 13.6 V. The AGM bank is observed as performing the same as at installation time, three years ago. The FLA 6 V's need water twice a year and specific gravity maintains consistent.

I don't see how any 12V AGM battery could not thrive at a 13.6 V float setting. Some mfgs advise a constant charge regimen much higher (15V). I have experienced an AGM battery opening it's vent. It took an inadvertent 19+V on a fully charged battery for more than an hour to pop it's valve. This was a smaller, 30 AH AGM.

[pnichols]

A) Mex: You're saying (I think) that the 0.4 difference between Lifelines's recommended float voltage (13.2 volts) and my/any stock converter's fixed output voltage (an average of 13.6 volts) should not (and in your case has not, yet) do harm to a LifeLine AGM battery .... regardless of what their rep told me.

B) That seems strange, as I believe that it's common knowledge that the 13.6 volts applied to a liquid acid battery can indeed boil it to death eventually if one doesn't add H2O periodically ... where the 0.4 volt lower float voltage (13.2 volts) from a multi-stage charger does not boil a LA battery.

The only reason I can think of for the above contradiction between A) and B) is that it must be that the one-way vapor pressure relief valve in Lifeline (and probably most other) AGM batteries DOES NOT/WILL NOT OPEN from the vapor pressure increase that occurs between using a float voltage of only 0.4 volts higher than that recommended at normal ambient storage and camping temperatures ... hence no drying out of the AGM battery happens at that (small?) higher-than-spec float voltage.

All the Lifeline tech had to do was tell me that at the time .... to keep from losing a sale of two of their Group 31 AGMs. I had the money ready to spend (.... although the two Group 31 Fullriver AGMs I bought with a spedified 13.6 volt float cost almost as much as Lifelines).

[Sam_Spade]

pnichols wrote:


LifeLine told me that 13.6 volts float left on their AGM batteries for months at a time (like myself and others do when their rigs are in storage at their home) would slowly dry them out over time and hence shorten their life.

Well then as far as I am concerned they are not "true" AGM batteries.

But I still don't believe that a lot of oil that is legally allowed to be labeled as "synthetic" these days really is either.

And I don't think you are doing anyone any favors by taking the one exception in the whole industry and quoting THAT as though it represented the "standard". It does NOT.

[MEXICOWANDERER]

Excessive plate erosion is what manufacturers strive to reduce. Acid being acid becomes more robust then regresses to being purely vicious as electrolyte exceeds 40c.

Yes or no? is there a temperature compensated 120 vac converter out there that meets Lifeline or Rolls & Surrette, temperature compensated specs for both bulk and float maintenance? "Dry them out?" Who at Lifeline verbatim declared 13.6 volts WILL DRY OUT A LIFELINE BATTERY? Please furnish a tech rep name? My MEE FINDING of not losing one gram of total unit weight over a period of 18-months makes a mockery of such a statement. Subtle voltage increase over Lifeline's recommended 13.2 - 13.3 volts @ 25c lineraly increase positive plate erosion. Now couple that bit of data with the fact that Lifeline batteries regularly last 5+ years IN UNDER-HOOD AUTOMOTIVE SERVICE. And I freakin' guarantee automotive regulator set points are not 13.2 volts, and I freakin' guarantee under-hood temperatures are not twenty-five degrees Celsius.

Many of you should be asking questions not making statements that defy logic or engineering expertise.

[pnichols]

Sam Spade wrote:

pnichols wrote:

Where do you think it's water vapor goes when you have too-high voltages (for the air temperature around it) applied to it too long?


Sorry but that falls into my definition of doing something really stupid.

But then your example goes to show that all batteries are not created equal.

I maintain that charging equipment designed and intended for wet cell conventional batteries, if working correctly, will be JUST FINE FOR AGMs too and water loss should not be a concern as the charging voltages will be lower than optimal not higher.

Sam ... "stupid" is relative to many things.

LifeLine told me that 13.6 volts float left on their AGM batteries for months at a time (like myself and others do when their rigs are in storage at their home) would slowly dry them out over time and hence shorten their life.

I "assume" that 13.6 volts float left on my AGM non-LifeLine batteries with a specified float voltage of 13.6 volts will NOT slowly dry them out and hence shorten their life ... due probably to a slightly different electro-chemical internal design that gives rise to their higher specified float voltage.

Also keep in mind that a float voltage becomes a bulk or boost voltage at high enough ambient temperatures around a LA battery ... per the charging voltage versus temperature charts for both liquid and dry (AGM) LA batteries. At high ambient temperatures that last the summer, one runs the risk of a constantly applied float voltage acting like a constantly applied bulk or boost voltage .... which of course is not a good thing.

I turn off the 13.6 floating volts on our RV's AGM batteries during long runs of hot weather to make sure they're getting the best long-life treatment.

[Almot]

MEXICOWANDERER wrote:
Six-tenths of a volt. Automotive charging system

I didn't mean alternator charging or starter battery specs, and this was not (mostly) the OP wanted to ask.

[MEXICOWANDERER]

Six-tenths of a volt. Automotive charging system alternator voltage regulator. .6 volts is to me at least, not a tweak. All the batteries installed in California Highway Patrol vehicles, have failed, especially the ones in the Antelope Valley, Mojave desert, Palm Springs, et al. Muse the fact these batteries operate at 120+ degrees. Aircraft voltage variances are even sloppier. The "failure" note is pure 100% sarcasm.

Absorbed Glass Mat batteries are a lot more forgiving than you may think. I.E. not wise to spend five hundred dollars trying to extend battery life by six months.

I wonder how many folks on this forum have AGM batteries in their automobiles? Temperature-wise an RV battery is molly-coddled. If AGM batteries were that sensitive to voltage, manufacturers would go broke replacing automotive warranty items.

I am just trying to get folks to ponder logic and not go off the rails over this. Find an AGM warranty that is voided if installed underhood in an automobile.

[Almot]

xyzHollyxyz wrote:
Love this forum.

What you see is normal 🙂

For you, being not able to measure SG because it is AGM, only one thing will work: following the recommended setpoints and temp comp. Those that were posted few pages ago, 14.3 and 13.4, IIRC.

Manufacturers could lie, tweaking specs a little on the paper to make their battery "unique", but if you will try outsmart them and not follow whatever is written - there is a good chance that you will make it worse.

[MEXICOWANDERER]

They pay me, I'll document it. Señor pnichols.

I already advised them. As far in as I got was

"Raising the float voltage would conflict with mil-spec values which have been in place for three decades"

Not losing one gram of hydrogen and oxygen, plus temperatures averaging <1F versus ambient tells the whole story. Whether a person takes this FINDING seriously is their personal choice. There is a hell of a difference between opinion and finding.

PS Because I am getting ready to move to warmer climes and here yesterday temps were 91/70 I put a 500 ampere shottkey rectifier in series with the WFCO power supply and the voltage is now reduced to 13.4 float. Voltage will be reduced to 14.3 during booooooooooost but that's fine.

Test your "special voltage" brand of AGM yourself. An AGM battery has a voltage ceiling in which amperage drops off rapidly to a tiny quantity. 14.4 or 14.8 volts do your own test and see exactly where voltage-wise this happens. Charge at 14.4 volts until the ceiling is reached, then crank up voltage and see for yourself amperage (increase?) coupled with length of time before the 14.8 charge limit hits the ceiling. If it's a very short time, then the higher voltage rate is a MOOT point.

This is why large manufacturers clandestinely hire outside engineers. In-house engineering staff members get brow-beaten by the senior staff engineer so their points are ignored. When warranty claims started to climb, my telephone rang. I reported to senior staff not the engineers. Senior plant engineers treated me like I was Hannibal Lectur and Benedict Arnold all rolled into one. I dealt with facts, not office politics, peer pressure, or sea-lawyering.