Quicker Battery charging

landyacht318 wrote:
Perhaps with a shallow discharge the time it takes to fully recharge does not matter, but Lifeline does not throw out their 20% figure just to confound the solar only recharger.

Anyone who does cycle to their AGM to 50% and just believes the low and slow solar, and their battery monitor, that the battery is jam packed full, is deluded.

People tend to put 100% confidence in their battery monitors, but the fact is is that they need to be set up correctly, are not 100% accurate even then, and they drift over time, and do not account for decreasing battery capacity.

http://www.pbase.com/mainecruising/programming_a_battery_monitor

So many people with battery monitors don't even have the shunt wired properly.

Blindly believing the battery monitor as 100% truth, is just as bad as believing a blinking green light for indicating full charge on any automatic charger.

They Lie, more often than not. Just because it is confidence inspiring to believe it, does not make it true.

If you are going to cycle deeply to 50% day after day for many cycles in a row, low and solar only recharges, are not going to keep AGMs as happy as they would be if a higher amp charging source was regularly employed from their most depleted level

How often they require a high amp blast from a depleted state is unknown to me, in such usage. I say mo often mo better.

I opt to almost never rely on my 200 watts of solar to properly recharge my Northstar AGM. 40 Meanwell amps + whatever the solar can make, or 65+ alternator amps+ whatever the solar can add. Solar can finish it off, but That high amp quenching at its lowest level of discharge is my Aim.

I do cycle deeply, and my observations when doing so every day are that voltage under the same loading tanks after 7 cycles of solar only recharge, and yes my controller is flashing the soothing, confidence inspiring green light, and my Battery monitor has also returned to 0AH from full plus some more, after amps taper to ~0.4a at 14.5v in the early afternoon, 3 different indicators that the battery is 100% charged, but it is NOT.

One 40+ amp recharge from 50%, and voltage under load returns to where it was on Cycle one.

My AGm is also my engine starting battery. After a week of ~50% nightly discharges and solar only recharges at a 10% rate maximum, it simply cannot crank my engine as fast as it can after a 40%+ amp recharge.

"Just fine" = just has not failed yet.

One does not have to seek ultimate lifespan of their batteries, but if someone posts a question here seeking ultimate longevity, replies by those who are not seeking ultimate lifespan, are not helpful. Everybody is going to seek a different level of acceptable.



Lifelines are so expensive, one should at least Know what they require to be happiest for longest.

50% nightly discharges for 2 weeks, and a 5% recharge rate is not 'just fine' with these high amp loving AGM's, even if the battery monitor says so and one places high confidence in blinking green lights.

Have you ah tested any batteries down to 10.5 volts as he suggested?

Or chronically undercharge them.

Bedliner would not do so hot if everything in the bed stuck to it. It dries hard and highly scuff resistant.

pnichols wrote:

As you probably have picked up on regarding AGMs ... keep them undercharged the minimum amount of time you are able to when camping and when in storage ..

Actually that is MORE important for a conventional wet cell because insoluble but conductive sulfates form much quicker when it is discharged. This is one of the main causes of battery failure.

Sulfation is not really a problem with AGMs at all.....unless maybe you leave them stone cold dead for a really long time.

MEXICOWANDERER wrote:
Go to Wallyworld. Look for tall can of TRUCK BED LINER spray paint. Product of RustOLeum. Ot laughs at hot battery acid. Black in color.

Once cured....which shouldn't take too long this time of year in Florida....would the batteries have a tendency to stick to it after sitting there for a LONG time ?

Thanks for the heads up. Think I'll give it a go, along with a soda bath, wire brush scrub and mild soap rinse.....and maybe a compressed air drying too.

Now all I have to do is figure out how to remove those batteries without tearing up my back. They are located in one of the steps going into the coach.

Before switching over to AGMs, just do the hot water/backing soda thing to remove the worst of the corrosion ... then sand a bit to get rid of any loose rust and old peeled paint. Finish up by just spraying color-matched Rustoleum paint (use the real stuff, not a knock-off) all over the area that used be covered with rust.

As you probably have picked up on regarding AGMs ... keep them undercharged the minimum amount of time you are able to when camping and when in storage ... whether your using a stock converter and/or an engine alternator. This works better than it does with standard batteries, because AGM batteries charge faster at any applied charge voltage.

All IMHO, of course.

Go to Wallyworld. Look for tall can of TRUCK BED LINER spray paint. Product of RustOLeum. Ot laughs at hot battery acid. Black in color.

MEXICOWANDERER wrote:
Batteries may see many winters before going to Happy Charging Ground.

Since this thread has already morphed a bit...........
I am considering changing over to AGM batteries, with the "stock" charging arrangements that I have because.......

It appears that they are seldom or never going to be discharged real deep and if they are, I should have plenty of time to recharge.
AND
It appears that the acid vapors (or splashing) from my conventionals is eating away at everything metal near the battery compartment.

Does anybody have any "quick and dirty" suggestions for arresting the present corrosion ? I figured on a good wash with baking soda and rinse, followed by thorough drying and a coat of grease.....with the batteries removed, of course.

Batteries may see many winters before going to Happy Charging Ground.

Bet they'll last longer than I do... :)

I'm just hoping to find a good balance between light cycling, equipment and attention to get my batteries to last a while. I may have gotten a deal but I cringe at the thought of the day I have to replace them.

pnichols ABSOLUTELY!

When manipulated correctly Trends & Tendencies is worth it's weight in gold. I use an amp hour meter for single cycle charge or discharge accumulations where error is reduced to near zero (No Peukert factorials). This is helpful when simultaneous charge and discharge (robbing from the charge rate) is occurring.

One of the reasons my abstract brain function at age 69 is equal or better than it was at age 40 is because I exercise it. There is no better exercise than functional mental exercise in which math is useful - relevant. Abstract functioning deduction of Trends & Tendencies is a boxing match grade mental exercise. If a mistake is discovered in deduction, it's like a left hook to the chin. It is painful. or at least it should be.

Boiling down and distilling observations to piece-of-cake battery management effort is the reward. It becomes intuitive. This leaves 23 hours and 56 minutes per day to pursue other activities.