Do AGM's charge quicker?

pnichols wrote:
Lilfeline does have recommended minimums, but as I suspected with respect to any AGM battery, they do talk about and warn against a danger of thermal runaway with use of large charging currents ... even though they do also talk about how it's possible to use large xC charging currrents.

This is basically all they have to say in their tech manual about max charge current:

The charging current during the Bulk stage should be set as high as practical; higher current
levels mean faster recharge time and less time for the plates to become sulfated. Due to the
low impedance design, Lifeline® batteries can tolerate in-rush current levels as high as 5C
(500A for a 100Ah battery).

David (MEXICOWANDERER) ... of course you already know this ... but here it is for those who don't: When a customer wants to buy a Fullriver battery they don't deal with any factory in China - they can deal with any one of 157 U.S. dealers - in addition to dealers in Canada, Europe, and of course Asia. ;)

http://www.fullriverbattery.com/content/distributors/north-america

6v Surrette/Rolls 415AH
Minimum 80 amps = 19.3%, Max 140 amps = 33.7%

http://www.wegosolar.com/products.php?product=S6%252d460AGM-Surrette-AGM-Sealed-Battery-6V-400AHR-%40-20hr

BFL13 wrote:
I see these 115AH Full River AGMs have a charging spec of min 20%, max of 35% at 14.7v . Seems to be several AGMs that have max rates, like my Stark 100AHs at 27%. My 8D says max is 100a for the 250 = 40%, but neither of these give minimums.

http://www.bestconverter.com/assets/images/Fullriver/fullrivermanual.pdf

FWIW just as reference I also checked out what Lifeline recommends. Their website seems a little long in the tooth and not the most user friendly. You have to look for just the right .pdf document and read down through several pages of it in order to find charging information that is a bit wordy and techie.

Lilfeline does have recommended minimums, but as I suspected with respect to any AGM battery, they do talk about and warn against a danger of thermal runaway with use of large charging currents ... even though they do also talk about how it's possible to use large xC charging currrents.

The Fullriver values you talk about seem to be right in the ballpark of what other AGM manufacturers recommend ... including those of Lifeline in their .pdf document.

When you're good -- flaunt it

http://rollsbattery.com/rolls-battery-manufacturer-warranty

Concorde uses lasers and robotics to maintain assembly tolerances and plate alignment to <.001 True of Rolls as well.

It takes a talented intermediary to interact with a Chinese factory that itself has inherent positive quality control (ready with ISO 9000-9001 specifications guarantees) to deliver a good product.

Battery is assembled and Inspected then it sits inside a container until a ship date is assigned.

Battery is transported from Guangdong Province to Hong Kong and sits until manifest date is reached

Container is loaded aboard ship

7,000 miles across Pacific Ocean

Awaiting unloading at Port

Awaiting Customs inspection (canine + radiation)

Transported to local shipping distribution point

Buyer arranges transport of container to their storage facility

Unloaded for shipment to regional storage

Then awaits sale

If you assume all this is done in a month's time you are a hopeless optimist.

Do you believe Mother Fletcher's AGM Batteries LTD are going to recharge those batteries? Perhaps the retailer will?

"Made In China" has some strings attached.

Have you any idea where the most sensitive area of a battery manufacturing plant is? Well, let's hear it...

I see these 115AH Full River AGMs have a charging spec of min 20%, max of 35% at 14.7v . Seems to be several AGMs that have max rates, like my Stark 100AHs at 27%. My 8D says max is 100a for the 250 = 40%, but neither of these give minimums.

http://www.bestconverter.com/assets/images/Fullriver/fullrivermanual.pdf

I have in excess of 13 Kw of chargers and that's a lot of energy. Maintain voltage control of a power source addressing a Lifeline and the battery will take care of itself.

1. Baldor 8.2 Kw 3 phase ferroresonant charger configurable

2. Allied 2.4 Kw 12 or 24 volt single phase charger (230 lbs!) USN

3. Trace 4024 120 amp charger

4. Delco 50DN 385 amp 24 volt alternator

5. Niehoff 24 volt 400 amp military alternator (Quicksilver)

6. And an assortment of 300 or so amps in small power supplies, including the Borg, and the Hyperwatt and 5 other power supplies.

I have more charger capacity than what the 6 cyl Kubota can handle.

A person would have to lay out careful plans to enable thermal runaway on a Lifeline. I agree with Lifeline that TR is unlikely. Their conditioning exercise takes the battery into the 17+ volt range.

What I seek is minimal generator run time, not a plastic goblet trophy from Guinness.

Jamming more amperage into the (Lifeline) battery has diminishing time reduction returns after C1 has been reached. But the time savings at C1 versus what standard converter output offers is appreciable. I can take both the standard and the 2-story from 50% SOC to "the wall" in slightly over four hours. Start the generator at 0800 and shut it off for lunch. But I have 24 wet cells to deal with -- worst case.

If I am running the diesel and power is restored, the diesel undergoes a 7 minute cooldown for the turbo and then it is secured. The single cells get 120 amps from the Trace and the Borg and Hyperwatt take care of the Lifelines. The Hyperwatt is a 56 amp Megawatt (highly modified) and the BORG is 2 Hyperwatts 112 or so amperes. CFE asked me if I would like to swap out my old-fashioned mechanical meter for a modern digital meter and I told them "In a pig's ***"

I have yet another 400 watt, Meanwell that is set on 13.5 volts to float the Lifelines and act as a UPS for my Respironics CPAP. Used to be a BiPAP until I was forced to rebuild it.

Looks like the power commission is improving reliability of the grid. Other than summer storm outages we might have dependable power. No matter how it's dealt .65 gallons per hour is $2.60 and a sixty plus mile drive wrestling drums in Jesus' Toyota.

Hope this helps

pnichols wrote:


Not necessarily. Suppose that the constant voltage power supply has current capacity sufficient to supply "all" that the battery can absorb at the constant voltage that you set the power supply at?

For an extreme example to get at a clear understanding - say a 500 amp power supply that you set to 14.7 volts in order to charge a single 12V Lifeline Group 27 battery. The power supply's maximum current probably cannot be reached before - regardless of what Lifeline may claim - the battery would go into thermal runaway.

What this means is that in order to do true constant voltage charging, the charger must have a current capacity that exceeds what the battery will ever absorb at that voltage.

Yes if you could find an ideal constant voltage source then your always in absorb, in the real world you don’t see many 500 amp 12v power supplies. Even then my two Lifelines would probably get it into overcurrent mode. Who makes 1000 amp power supplies?

And if your batteries don’t like 5C charging its probably good to get a power supply with a adjustable constant current threshold so you can dial in the proper max amps. Some of those power supplies also have timers that will adjust the constant voltage setpoint after it has been reached to a lower setpoint and reset back again if voltage drops beyond another setpoint. They are called 3 stage chargers.

MEXICOWANDERER wrote:

A good one David!

Except that ... time is merely a system for keeping track of configuration changes within the universe.

Money is far more complicated than that. :B

."As battery charges the voltage to maintain max power supply output will rise until hitting power supply constant voltage setting, at which point current will be lowered to maintain set voltage. This is absorb charging"

When I do it, I set say 14.8 on the charger and by the time amps start to taper, voltage is say 14.4 on the charger and 14.2 on the other end of the wires at the battery. Then during Absorption, as amps taper 14.6 and 14.5 (less voltage drop with fewer amps) and then at "Full" it will be 14.8 and 14.8