Can't Get My Batteries Fully Charged

[kellystalker]

Thanks so much. I'm just getting back to our conversation now. I really appreciate the feedback you are providing. I will definitely explore these options. Currently, the absorb time has been set for 6 hours at 30.0 V. I will have to check with the dealer if there is any more room to increase the V but the absorb time can certainly be played with especially if the PV panels can handle it during the day.

I'll give it a shot this week and let you know the outcome. Unfortunately, for the next few days we have patchy weather but next week things will improve.

Thanks again for your help. I really appreciate it.

Kelly

There are two basic strategies to use when panels and generator are in the right ballpark for the bank size and the load:

1. Run the generator early in the morning to handle the bulk stage quickly and efficiently (generator constantly at near maximum output), then let the PV carry through the absorb into float, assuming that can be finished within the total amount of daylight available. Or
2. Let the panels do the bulk and start the absorb and just stop when the light runs out, but at least to 80% SOC, then plan to finish off using the generator at least once or twice a week.

In either case, if the batteries can take it, set the Absorb voltage higher to keep the CC in bulk mode longer. This will reduce the time spent not using the full available PV output, and can make it more possible for the PV to finish absorb at least some of the time.

If you just do not have enough combined PV and Generator, you will have to reduce your load somehow.
Remember though that using the generator for the tapering-current absorb stage is a waste of fuel and generator hours.

[inetdog]

What kind of battery charger (amps) is the generator powering? How long do you run it? Do you set the charger to Equalize?

If I had to guess is you are not running it long enough.

There are two basic strategies to use when panels and generator are in the right ballpark for the bank size and the load:

1. Run the generator early in the morning to handle the bulk stage quickly and efficiently (generator constantly at near maximum output), then let the PV carry through the absorb into float, assuming that can be finished within the total amount of daylight available. Or
2. Let the panels do the bulk and start the absorb and just stop when the light runs out, but at least to 80% SOC, then plan to finish off using the generator at least once or twice a week.

In either case, if the batteries can take it, set the Absorb voltage higher to keep the CC in bulk mode longer. This will reduce the time spent not using the full available PV output, and can make it more possible for the PV to finish absorb at least some of the time.

If you just do not have enough combined PV and Generator, you will have to reduce your load somehow.
Remember though that using the generator for the tapering-current absorb stage is a waste of fuel and generator hours.

[Sunking]

What is the make and model of this inverter? Sounds like you are just not running the generator long enough to get the SPG up. Root cause of the problem sounds like you are using way more energy than the system can generate. That means it is undersized. You are using more power than you think you are.

[kellystalker]

It's a 6W generator. My understanding is that when the generator is running that the inverter diverts whatever power is necessary to the batteries. I notice that when I first turn the generator on it reads the Bulk Voltage plus 112 or more amps. The amps slowly go down over the charging. To that point, we keep upping the absorb time to see if that works but the voltage settings are now at the higher end of what's recommended for those batteries. I have not done an equalize charge since the batteries were reinstalled (10 days ago) as the dealer didn't recommend it. There has never been a time when the batteries have been fully charged except when they came from the dealer and I could have run the generator for 10 or 12 hours at a time to get no-where. So this is part of the puzzle.

What kind of battery charger (amps) is the generator powering? How long do you run it? Do you set the charger to Equalize?

If I had to guess is you are not running it long enough.

[Sunking]

Do you have a sense of why the batteries won't charge fully even when the generator is charging them?

What kind of battery charger (amps) is the generator powering? How long do you run it? Do you set the charger to Equalize?

If I had to guess is you are not running it long enough.

[kellystalker]

I am in Falkland, British Columbia which is north of Vernon, B.C. (North Okanagan).

Do you have a sense of why the batteries won't charge fully even when the generator is charging them?

Your assessment is likely correct. Current should start rising as summer approaches.

I will give the dealer the benefit of a doubt because they likely took an educated guess as they had no hard data on power usage from you.

With all that said I know what is wrong. You are simply using more power each day than the panels can generate. As I said earlier based on battery size alone, they are capable of providing you with up to 5 Kwh/day. That does not mean your panels can generate that.

OK what is your location?

With that info I can at least calculate what panel wattage is needed to provide you with up to 5 Kwh per day in winter months.

[Sunking]

In terms of output, we've had a rough winter and spring but when the sun is out at high noon, we are getting closer to 40 amps and not the 60 you are suggesting. I keep imagining that as spring progresses we will see an improvement.

Your assessment is likely correct. Current should start rising as summer approaches.

Your thoughts on the size of our panel array interest me. I will have to discuss this with the dealer. I ask retorically, why would they have recommended this number of panels if they couldn't ever charge the batteries correctly?

I will give the dealer the benefit of a doubt because they likely took an educated guess as they had no hard data on power usage from you.

With all that said I know what is wrong. You are simply using more power each day than the panels can generate. As I said earlier based on battery size alone, they are capable of providing you with up to 5 Kwh/day. That does not mean your panels can generate that.

OK what is your location?

With that info I can at least calculate what panel wattage is needed to provide you with up to 5 Kwh per day in winter months.

[kellystalker]

Thank you so much for your reply. I will try to answer some of your questions as best as I can.

It seems like I am underprepared. My dealer provided a glass hydrometer but I don't have a thermometer as it wasn't specified. Please try to understand that I am a complete lay person when it comes to this. Although I am learning every day, I have been operating our system based on the recommendations of the dealer and Magnum.

In terms of output, we've had a rough winter and spring but when the sun is out at high noon, we are getting closer to 40 amps and not the 60 you are suggesting. I keep imagining that as spring progresses we will see an improvement.

So you ask about watts. If I can use another measurement because I pay closer attention to this on the remote and I'm not good with converting measurements. On AVERAGE we are using between 8 and 10 amps per hour. When the house is not under load (say for example the fridge's compressor isn't running) then we are running at 2 amps for the whole house. Our fridge is electrical but our stove and dryer are propane. We have LED lighting and we heat our house by wood. Our house is passively designed.

Your thoughts on the size of our panel array interest me. I will have to discuss this with the dealer. I ask retorically, why would they have recommended this number of panels if they couldn't ever charge the batteries correctly? My understanding is that our system is capable of providing a 30 amp service with room to expand to 40 without more infrastructure.

I run the generator all the time. I have been basically running the generator every 36 to 48 hours since we went live in January but given our consumption habits I was expecting between 48 and 72 hours. So running the generator has and always was to top up the batteries. We just aren't getting the specific gravity the dealer is aiming for. Incidentally, when we got the batteries back after sulfating ordeal, I used the hydrometer to check the batteries before they were reconnected and got the 1275 we were looking for. So I know the batteries are capable of it but the charging parameters here at home are not working. It keeps me up at night because we have a lot of money invested in these batteries. Magnum assures me that there default settings are adequate for most batteries but its not working for these ones. So in my initial post I gave our most current settings.

Thanks again.

Kelly I can help you out. or at least get to the bottom of things, but I am going to need to ask some questions.

First order of business is you battery monitor. They are basically worthless as you have noticed. The problem is State of Charge voltages (SOC) are only ball park voltages and only apply to a battery that has been disconnected and allow to rest a few hours. Working solar systems and never at rest. The batteries are either being charged or discharged. The only accurate way to determine the SOC is with a highly accurate thermometer and hydrometer. Your hydrometer is telling you the battery is low, but did you compensate and adjust the reading according to Temperature.

Q1. During the day when the sun is out and bright around noon, how much charge current is output from the Charge Controller? You Midnight Solar CC will tell you that. With 1710 watt panels on a 24 volt battery you should be seeing around 60 amps.

Q2. How many watt hours per day are you using from the batteries?

Here is my first suspicion. You are using more power than your panels can generate and replace each day. Based on batteries alone being 24 volt @ 1050 AH tells me the the batteries are capable of supplying 5 Kwh/day. However given your location and panel wattage, the panels cannot generate the 7.5 Kwh to replace 5 Kwh to the batteries.

Until you get this figured out, you need to start using your generator to keep the batteries topped off. Otherwise you will destroy them. You already raised a Red Flag with the manufacture telling them you are abusing your batteries, especially since you have a generator. That tells the manufacture and me you are not using it or using it properly. If you were, you would not have to send them off for someone else to charge them for you.

[Sunking]

I don't understand why the BMK Monitor says the SOC is 100% but the specific gravity does not indicate this.

Kelly I can help you out. or at least get to the bottom of things, but I am going to need to ask some questions.

First order of business is you battery monitor. They are basically worthless as you have noticed. The problem is State of Charge voltages (SOC) are only ball park voltages and only apply to a battery that has been disconnected and allow to rest a few hours. Working solar systems and never at rest. The batteries are either being charged or discharged. The only accurate way to determine the SOC is with a highly accurate thermometer and hydrometer. Your hydrometer is telling you the battery is low, but did you compensate and adjust the reading according to Temperature.

Q1. During the day when the sun is out and bright around noon, how much charge current is output from the Charge Controller? You Midnight Solar CC will tell you that. With 1710 watt panels on a 24 volt battery you should be seeing around 60 amps.

Q2. How many watt hours per day are you using from the batteries?

Here is my first suspicion. You are using more power than your panels can generate and replace each day. Based on batteries alone being 24 volt @ 1050 AH tells me the the batteries are capable of supplying 5 Kwh/day. However given your location and panel wattage, the panels cannot generate the 7.5 Kwh to replace 5 Kwh to the batteries.

Until you get this figured out, you need to start using your generator to keep the batteries topped off. Otherwise you will destroy them. You already raised a Red Flag with the manufacture telling them you are abusing your batteries, especially since you have a generator. That tells the manufacture and me you are not using it or using it properly. If you were, you would not have to send them off for someone else to charge them for you.

[kellystalker]

I'm new to the forum so I will provide a little background on my situation. We live off the grid. This is a new system that was installed in January 2013. It was a package deal designed with automation in mind in that we could walk away from the house and it would look after itself. Our package includes:

MS4024-PAE Magnum 4000 W INV/CHGR
ME-ARC50 Remote
CLASSIC 150 Midnite CHG Controller
9 - i190P Invensun 190W Panels
4 - TS-1560 Tubular Solar 6V, 860 AH @ C5 Batteries or 1050 AH @ C20 (These are 2V batteries in sets of 3)
ME-AGS-N Magnum Generator Start Module
ME-BMK-NS Magnum Battery Monitor Kit
Ecogen 6W Propane Tie-In Generator

Since day one of installation we have been unable to fully charge the batteries. Initially we thought there might have been a problem with the batteries and so we uninstalled them and sent them back to the dealer (at great expense and effort as they weight 350 lbs each). They put them on a high powered charger to dislodge any sulfates and got the specific gravity back to 1275 which is the optimal range for these batteries. Now 10 days back into getting these batteries back up and running, we still can't get them fully charged.

We have changed the charging parameters a few times. As of today these are 30.0 VDC for bulk/absorb, 27.3 VCD Float and 31.4 VDC for equalize. After 6 hours in absorb they still did not reach the green on my hydrometer and no further gains were made. I have contacted Magnum more times then they care to hear from me and my dealer is also frustrated. I feel the desperation setting in as running the generator every other day due to low capacity is costing a fortune (not to mention not environmentally friendly).

My understanding of our system is limited to knowing how to scroll through the menus to change settings and how the components interact and I have updated the firmware. I don't understand why the BMK Monitor says the SOC is 100% but the specific gravity does not indicate this.

Any help or suggestions you have is greatly appreciated.

Kelly