battery charging voltage

The calculation is for 14.4 volts. .5% amp-hour total. <2.0 amperes @ 14.4 volts = 400 A/ H

Hi Mex,

I set it at 13.8 volts.

@ ¿voltage?

After 4 hours of solar and float charging the four batteries are accepting less than 2 amps.

I think you may like what you experience re power

Hi,

A bit more information.

The telecom batteries had been sitting for a month without being charged. Voltage was 12.83, 12.85, 12.87 and 12.9

I have paired them 12.83 with 12.85, and 12.87 with 12.9

The 12.87/12.9 pair appeared to be accepting 1.5 amps of charge.

The old marine walmart batteries -- three were ok and one had a bad cell.

Trying to make electrochemical sense is no easy job. Batteries that are discharged shallower, recharged sooner have an easier time of it. A solar system that can bring a 50% SOC to 100% SOC daily is the theoretical ideal. Such a system would be close to OEM's recommended 20% of amp hour capacity minimum recharge amperage. Solar chops off any notion of cheating with a lower amperage but longer duration recharge coupled with a tweaked float voltage limit. I cannot walk up to an AGM solar system, wave a magic wand and tell the owner his bank is in trouble. Why the fuss - you ask? One AGM is one thing 12-L-16's quite another. If you are happy with your system then drive a sixteen penny nail and walk away. I am in the same nail-biting position of a huge bank owner. If the bank or battery shortchanges me - I'm screwed. I am forced to by circumstances to present ideals. Generally adopted by industry because it represents theoretical maximum lifespan. I encourage folks to read and re-read the downloadable Concorde Lifeline PDF manual for AGM batteries. I live in a country where a lot of people drive a nice pickuo from pothole to pothole at 80mph, seldom change oil and are satisfied when the vehicle finally needs major surgery at 80,000 miles. They cannot be convinced to drive slower or take better care of their cars. Many think I am an idiot on the road for hitting the brakes for a 4" deep pothole. It's similar with some folks and their philosophy with battery maintenance. I refuse to twist elbows. I try and pass along facts and what the user does is his bag not mine. But trouble brews when somone suggests I drive my car 80-mph pothole to pothole.

Non acid starved AGM batteries are built that way for a purpose. For every positive point there exists a negative. Including price, CCA, vulnerability to over discharge. No free lunches. Education is the key for folks who wish to minimize the negative and maximize the positive.

pianotuna wrote:
Hi Mex,

Since I have four does that mean 2 amps instead of 0.5 amps? So far as I am aware the Magnum does not have a "timer" so it should stay in absorb until the batteries are ready to float.

MEXICOWANDERER wrote:
Yep. This is why Concorde issued succinct instructions for charging then knowing for a fact the battery is 100% charged before reverting to float maintenance. I would suggest trying their formula with your battery manufacturer's recommended VMAX. In your case sir, point five amperes then see if float amperage climbs. An increasing float amperage is a classic tattletale the battery has been forced to float before it is fully charged.

Yes, 2A, but that is in addition to any existing loads. If you have a 3A load, then transition to float can/must begin at 5A. Smart chargers have no way of knowing your loads and that is where timers are needed to force the transition to float Volts.

My little MMS 1012 has a non-adjustable 2hr timer during Abs. My draws are 2 x 12V fridges. I have not observed more than 90min in Abs, likely because at some point neither fridge was running.

Check your remote's manual.

Mex's external spring-wound timer serves the same function, i.e., at some point in time you need to transition to float. The difference is that it is possible for our automatic chargers to transition too soon. That is overcome by you knowing how your charger works.

Now while in float, the MMS has a 4hr timer before shutting down. During the shutdown the Volts are monitored and another 4hr float is started at 12.9V. I rarely see this happen because the of the fridges.

If I wanted to force a more constant float, I would use an external day/night timer to interrupt the AC input at four hour intervals.

HTH;
John

MEXICOWANDERER wrote:
VOLTAGE LIMIT WHEN CHARGING.

An excess acid AGM can be damaged easier by overdischarge than can a classic acid starved AGM design. Slightly thicker mats hold more acid. Less CCA same 20 hr rate greater 100 hour rate. If you like your new to you telecomm treat is like a normal AGM battery. Don't cheat and slow charge them or play with absorbsion or float. Don't repeatedly undercharge the battery.

So the main difference between a "classic Acid Starved AGM", which is the normal AGM I guess, and an "excess acid AGM", which I guess is typically a telecomm AGM, is just that an "excess acid" AGM has "Slightly thicker mats " that "hold more acid" ???. Sorry, this is new terminology to me, and Google is no help.

And yes, I too am spoiled with a solar controller that has either/or time based and current based termination of the Absorb stage. I rarely have to touch my batteries with anything else ...

Hi Mex,

I can not find a vmax but equalize and system cycle voltage is listed as 14.4 to 14.8.