Set-up and performance

[Wade Mc]

New to the site, and love what I see. I have a question...

I have a good quality solar array of almost 2400 watts, I have a Magnum MS4024PAE Inverter, an Outback FlexMax 80 charge controller, and 12 GNB Absolyte 100A-25 1200a/hr batteries. Checking their site it should be 1600 A/hrs. Being in central Ontario the solar is good from May till November. November hits no sun usually all month, maybe 4 days of sun in Dec, and maybe 4 days full sun in January... (Lake effect from West wind off Great Lakes). This said, I run my 7000W generator to keep going. My system is 1.7 yrs old. Due to Geography, my whole solar outfit is in the non heated garage in a small well insulated room 70 feet from the house..

Now...
Problem is, if I charge to 26 volts, shut charging down the volts drop like a stone to 24.8 in half an hours. Wondering if I got bad batteries, part Cold effect? My average daily use is around 200 amps at 24 volts... GNB are suppose to be best 'cold' batteries going?

[Sunking]

I have a good quality solar array of almost 2400 watts, I have a Magnum MS4024PAE Inverter, an Outback FlexMax 80 charge controller, and 12 GNB Absolyte 100A-25 1200a/hr batteries. Checking their site it should be 1600 A/hrs. Being in central Ontario the solar is good from May till November. November hits no sun usually all month, maybe 4 days of sun in Dec, and maybe 4 days full sun in January... (Lake effect from West wind off Great Lakes). This said, I run my 7000W generator to keep going. My system is 1.7 yrs old. Due to Geography, my whole solar outfit is in the non heated garage in a small well insulated room 70 feet from the house..

Now...
Problem is, if I charge to 26 volts, shut charging down the volts drop like a stone to 24.8 in half an hours. Wondering if I got bad batteries, part Cold effect? My average daily use is around 200 amps at 24 volts... GNB are suppose to be best 'cold' batteries going?

I am so sorry, you have 12 toxic boat anchors. GNB Absolyte are about the worse battery ever made, thus why they quit making them 15 years ago. In addition they are Emergency Standby Batteries made for Telecom and only have maybe 50 to 100 cycles in them ot 3 years which ever comes first.

Telecom where you bought them from play dirty little tricks, I know I use to do it. They are responsible for disposal of the batteries, and that is very expensive. To to relieve themselves of the cost and Employment Prevention Agency Red Tape of disposing so much toxic waste, they sell them instead and turn a huge liability into a little bit of cash. Now you are stuck with a huge liability and EPA Red Tape. Congratulations, you are now the owner of a 2400 pound toxic boat anchor no one wants.

[inetdog]

New to the site, and love what I see. I have a question...

I have a good quality solar array of almost 2400 watts, I have a Magnum MS4024PAE Inverter, an Outback FlexMax 80 charge controller, and 12 GNB Absolyte 100A-25 1200a/hr batteries. Checking their site it should be 1600 A/hrs. Being in central Ontario the solar is good from May till November. November hits no sun usually all month, maybe 4 days of sun in Dec, and maybe 4 days full sun in January... (Lake effect from West wind off Great Lakes). This said, I run my 7000W generator to keep going. My system is 1.7 yrs old. Due to Geography, my whole solar outfit is in the non heated garage in a small well insulated room 70 feet from the house..

Now...
Problem is, if I charge to 26 volts, shut charging down the volts drop like a stone to 24.8 in half an hours. Wondering if I got bad batteries, part Cold effect? My average daily use is around 200 amps at 24 volts... GNB are suppose to be best 'cold' batteries going?

At least you are in the right ball park with a 24V system instead of 12V and by using 2V batteries in series to make up that 24V instead of paralleling 12V batteries. Sorry to hear that your battery choice was not ideal.
One thing that Sunking knows in great detail is the type of batteries used by Telecom for float service. Is there any date code on your batteries?

[Wade Mc]

I am so sorry, you have 12 toxic boat anchors. GNB Absolyte are about the worse battery ever made, thus why they quit making them 15 years ago. In addition they are Emergency Standby Batteries made for Telecom and only have maybe 50 to 100 cycles in them ot 3 years which ever comes first.

Telecom where you bought them from play dirty little tricks, I know I use to do it. They are responsible for disposal of the batteries, and that is very expensive. To to relieve themselves of the cost and Employment Prevention Agency Red Tape of disposing so much toxic waste, they sell them instead and turn a huge liability into a little bit of cash. Now you are stuck with a huge liability and EPA Red Tape. Congratulations, you are now the owner of a 2400 pound toxic boat anchor no one wants.

Well it was the guy who installed my system told me they were the best thing going.... Especially in the cold. This guy pissed me off from the beginning. I have asked him many question he can't answer. I work in Electrical Engineering and mechanical Engineering. I researched these batteries and their website was not full of information.... Can you give me as much info as you can or anywhere I can find more. I will have a few lawyers crawl up this guys butt till I get my money back.

[Wade Mc]

At least you are in the right ball park with a 24V system instead of 12V and by using 2V batteries in series to make up that 24V instead of paralleling 12V batteries. Sorry to hear that your battery choice was not ideal.
One thing that Sunking knows in great detail is the type of batteries used by Telecom for float service. Is there any date code on your batteries?

I will check the date codes for you. What freaked me out is when I went to GNB's web site I could not find these batteries anymore. And he had quoted me different batteries in the first place. I also noticed after the install another "real" electrician signed off on it from 250 miles away.

[Sunking]

I will check the date codes for you. What freaked me out is when I went to GNB's web site I could not find these batteries anymore.

Real simple GNB quit manufacturing them 14 years ago. GNB went bankrupt from warranty claims and was bought out by Exide in 2000. Starting in 1995 I installed thousands of them while working for MCI-Worldcom in fiber Regen Sites all across the USA. By 1999 we had to go back and replace all of them at GNB expense until they filed bankruptcy. It cost us ten's of millions to replace them. Exide redesigned the product and is now called Absolyte-IIP. The older version had 3 major issues.

Leaky seals around the term post.
Look at them cross-eyed and they would go into Thermal Runaway.
Complete capacity loss after 5 years on a 20 year warranty.

What I cannot understand is why any pro would opt to use Telecom Station batteries. They are not designed for cycle service. They are designed to discharge at very high rates of a few hours, and be recharged very quickly in a few hours. What your installer did was buy salvaged, and then sold them to you for new. Those batteries were DOA 15 years ago when they got yanked out of service. You got screwed and liked it at first without being kissed.

[Willy T]

Now...
Problem is, if I charge to 26 volts, shut charging down the volts drop like a stone to 24.8 in half an hours. Wondering if I got bad batteries, part Cold effect? My average daily use is around 200 amps at 24 volts... GNB are suppose to be best 'cold' batteries going?

Most batteries would be a issue, your only charging them to 50% at best.

[Wade Mc]

Most batteries would be a issue, your only charging them to 50% at best.

What are they suppose to be brought to after float? Hard to tell at -15 C.

[Wade Mc]

Real simple GNB quit manufacturing them 14 years ago. GNB went bankrupt from warranty claims and was bought out by Exide in 2000. Starting in 1995 I installed thousands of them while working for MCI-Worldcom in fiber Regen Sites all across the USA. By 1999 we had to go back and replace all of them at GNB expense until they filed bankruptcy. It cost us ten's of millions to replace them. Exide redesigned the product and is now called Absolyte-IIP. The older version had 3 major issues.

Leaky seals around the term post.
Look at them cross-eyed and they would go into Thermal Runaway.
Complete capacity loss after 5 years on a 20 year warranty.

What I cannot understand is why any pro would opt to use Telecom Station batteries. They are not designed for cycle service. They are designed to discharge at very high rates of a few hours, and be recharged very quickly in a few hours. What your installer did was buy salvaged, and then sold them to you for new. Those batteries were DOA 15 years ago when they got yanked out of service. You got screwed and liked it at first without being kissed.

You are freaking me out now... you mean this model 12 GNB Absolyte 100A-25 1200a/hr batteries. Hasn't been manufactured for 14 years???? Or are you talking Exide in general because they sell alternative energy batteries.When you go to their website they say they are the best in the land....(of course). When I emailed Exide they never answered. Also, this explains when I asked my installer what he set the parameters up at for the charge controller he would tell me not to touch it, and never answer my questions. Blood is boiling now!!

[Willy T]

What are they suppose to be brought to after float? Hard to tell at -15 C.

You didn't say that you are doing a Full 3 stage charge cycle. Tell us your charge settings ( Voltages ) and how long the absorb is ( time ).

if I charge to 26 volts, shut charging down the volts drop like a stone to 24.8 in half an hours

[Sunking]

You are freaking me out now... you mean this model 12 GNB Absolyte 100A-25 1200a/hr batteries. Hasn't been manufactured for 14 years????

That is what I am telling you. GNB was an Australian battery that went bankrupt in 1999 from making the Absolyte battery. They were horrible and went bankrupt from Warranty Claims. When they came out of bankruptcy court Exide bought what was left of the comapny to obtain the manufacturing plants and intellectual property like Patents and Company Name (GNB) for pennies on the dollar and did not have to honor anymore warranty claims.

Exide redesigned the battery which is now called GNB Absolyte-IIP or second generation and released it sometime around 2001/2002 and still makes them. Those batteries are OK. You can buy new GNB Absolyte-IIP 100a-25 today made by Exide. Many telecoms especially Cell Site Tower operations use them. But that is not what you have if they are labeled GNB Absolyte 100A-25. Those are the 1st generation boat anchors GNB quit making in 1999 and went bankrupt with. If that is what you have your contractor bought them or given to him from a Telco that has had them sitting around for at least a decade trying to find someone to give them to. Most Telcos just give them away to get rid of them so they do not have to suffer the expense of disposing them. MCI-Worldcom was giving away brand new GNB's still in the original shipping crates from 2000 to 2003 when they went bankrupt. The other 1100 or so sets that were installed magically disappeared via E-Bay by contractors who removed them from service and were told to make them disappear.

Show me a GNB Absolyte battery, and I will show you a boat anchor. Not to be confused with a GNB Absolyte-IIP second generation made by Exide.

[Sunking]

What are they suppose to be brought to after float? Hard to tell at -15 C.

Kind of a moot point with these batteries but they are intended to be float charged to 27 volts at 25 degrees C. If in cycle service which they are not designed for is 28.2 volts for daily charge. But what you are seeing is what one would expect for a dead battery. You charge them up to say 27 volts until current tapers off to .03C and when the charge is removed the voltage collapses

At -15 degrees C using Temperature Compensation the voltage goes higher to:

V corrected = V25°C - (( T actual-25°C) x ( .0055V/°C)) or
V corrected = V77°F - ((T actual-77°F) x (.003V/°F))

However all this irrelevant since you have boat anchors. These batteries were designed to be used in float service using a 300 to 1200 amp 24 volt rectifiers used in telecom. They are intended to supply up to 1200 amps of load, then be charged at very high rates up to 1C or 1200 amps.

I am sorry as I know you do not want to hear any of this, but if they are in fact the original GNB Absolyte batteries, they are at least 14 years old and shot to hell.

[Wade Mc]

Kind of a moot point with these batteries but they are intended to be float charged to 27 volts at 25 degrees C. If in cycle service which they are not designed for is 28.2 volts for daily charge. But what you are seeing is what one would expect for a dead battery. You charge them up to say 27 volts until current tapers off to .03C and when the charge is removed the voltage collapses

At -15 degrees C using Temperature Compensation the voltage goes higher to:

V corrected = V25°C - (( T actual-25°C) x ( .0055V/°C)) or
V corrected = V77°F - ((T actual-77°F) x (.003V/°F))

However all this irrelevant since you have boat anchors. These batteries were designed to be used in float service using a 300 to 1200 amp 24 volt rectifiers used in telecom. They are intended to supply up to 1200 amps of load, then be charged at very high rates up to 1C or 1200 amps.

I am sorry as I know you do not want to hear any of this, but if they are in fact the original GNB Absolyte batteries, they are at least 14 years old and shot to hell.

I'm so sorry Sunking. They are IIP batteries, they are the new type. I'm not sure of the length of the absorb charge, but the float charge is as high as 4 hrs. I also had contacted Outback being concerned with over charging. I was told the charge controller prevents over charging. I asked my installer what was the DOD set at on the charge controller before the system shuts down. Again he never answered me and told me not to touch it. I asked him for my password for the charge controller and he said not to touch it. Now he doesn't answer my emails. I think I know more about this than he does.... I am still concerned with how fast the volts drop. I'm relieved to hear they are the next generation and only 1.7 years old. I am so sorry to have miss lead you, but God I sure appreciate your knowledge. This forum was the best place I could have come!! Magnum and Outback have been very helpful too.

I do electrical and mechanical designing, but have little battery knowledge. I need to change this, and joining here is a great start!! I have been quite diligent on keeping the charge up. They are glassmatte so no maintenance. Just paranoid because they are oout in the cold garage.

[Wade Mc]

You didn't say that you are doing a Full 3 stage charge cycle. Tell us your charge settings ( Voltages ) and how long the absorb is ( time ).

Hi Willy,

Just had them on float charge an they were at 26.7V. It is -10 celcius out right now, and I'm waiting and hour to check back on them. I'll edit when time is up. Droppped to 25V in 1 hour, hoping this is because it i cold.

[Sunking]

OK lets start over. You said you have 2400 watts of panels on a 24 volt 1600 AH battery, and cannot get to an acceptable end charge voltage right?

Fist thing I can tell you right away you do not have enough panel wattage for the batteries. You want at least a C/10 charge rate on a 1600 AH battery with a 20 hours discharge rate. I assume you have an 80 amp MPPT controller and at 2400 watts on a 24 volt battery will get you only 80 amps of charge current. But you need 160 amps, and with these short winter days only get at best 3 to 4 Sun hours if you live in the south. Up north way less.

Your batteries are in desperate need of an EQ Charge and yesterday was too late. Get you a 200 amp battery rectifier with adjustable voltage output the kind Telecom uses. Fuel up the generator for 24 hours of fuel. Set the output voltage to 28.2 volts and charge until current tapers down and is constant without dropping for 3 hours with no load current flowing. All this is covered in the manual

Also refer to the manual for CYCLE SERVICE charging. If discharging more than 5% in a daily cycle, you set daily charge for 2.38 volts per cell (28.5 volts) and charge until the sun goes down and pray it was long enough. There is no Bulk or Absorb stages with this battery. Only Float and EQ. Float voltage is set by daily DOD percentage. Read the manual section 12 (Cycle Service) closely many times until you fully understand it. Then read section 13 (Equalizing) many times until you understand it. Once you do that you will understand what is wrong.


What you will discover is you are in Deficit Charging. Batteries are not like money, there is no credit or debt forgiveness. Get behind, you destroy the batteries and get to buy new ones. No exceptions. Hopefully you have caught this in time. Be prepared to run the generator a lot. Right now until you get a handle on daily watt hour usage, I think your panel wattage is like peeing on a forest fire with these batteries. You will not know that unless you know your daily watt hour usage and Sun Hours. There can only be one of two things. Either your panel wattage is way to low, or your batteries are way over sized.

A properly sized system is designed so the panels can resupply your daily usage under worse case conditions which means winter Sun Hours in most cases. Batteries are sized to have 5 day reserve capacity. Inverter usually no larger than panel wattage or less. Generator sized to recharge in 8 hours plus carry your load. AC charger to provide 8 hour charge rate.


FWIW at your current panel wattage, you should be using a 48 volt system. Once you hit 2000 watts, you cross the 48 volt line. Those batteries need 160 amp charge current. That is 5000 panel watts and two expensive 80 amp charge controllers. A 48 volt 800 AH battery (same energy of 24 volt @ 1600 AH) still requires 5000 panel watts but only a single 80 amp controller.