Evaluation
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Note: |
Apparently, I went looking for the Deka manufacturer at this point and found East Penn Manufacturing and filled in their 'Contact Us' form.
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MK Battery to Van Dec 3, 10:06 AM |
Hi Van, I got passed along your information from East Penn. We are a wholly owned subsidiary of East Penn and handle everything solar related for them. You contacted East Penn but there wasn't much detail on your inquiry. How can I help you? Isaac Wels, Sales Support, MK Battery 1631 S. Sinclair, Anaheim, CA 92806, 714-922-2032, 800-372-9253, iwels(At)mkbattery.com
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Van to MK Battery 10:56 AM |
Thanks for responding. Their message box was unable to take all of my text, so I was dropped into an Error message.
On Jan 12, 2012 I bought 16 B-DK-8A27 Deka AGM Batteries from Backwoods Solar to replace the 12 Optimas that I had installed in 2007. I did so because my solar system just wasn't holding a charge like it used to.
The 16 Dekas did not seem to make any difference. Then I went away for 7 months and am now back.
While away, a minimal load was active. It kept my desktop running 24/7 (plugged into a Cyberpower 1500PFCLCD UPS), along with 5 cameras (2 PTZ), a Crosley chest fridge and two daytime water pumps. I stayed in touch with it all through TeamViewer. With our return, the load is of course heavier, but no more then the load before the Optimas began to weaken.
Around mid afternoon, I unplug the fridge, the cameras and don't even think about the coffee maker (on its own UPS) or microwave, etc., just to have some lights through the night. By morning, the charge on the 16 Dekas sits around 41V 0.0A.
Now, at 11 AM, it is at 52V 13.0A. The panels show an input of 53V under a cloudy sky, which will increase to around 63V in an hour or two.
I have an Outback MX60 charge controller and a Mate3 monitor plugged into it. Also an Exeltech XP 1100 inverter.
It has been suggested that I should Equalize the battery bank frequently until and if that solves the problem. The MX60 manual says "Do not equalize sealed batteries".
You can see my setup at:
https://www.blakeman.net/_VA/CA/JT/2011/Solar/solar2011.htm
What should I do? Thanks, Van Blakeman (BTW: I prefer email so that I can remember what was said.)
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MK Battery to Van Dec 3, 12:21 PM |
Hi Van - Thank you for the detail and contacting the DEKA SOLAR TEAM. Let's start with a few questions and the DEKA renewable charging set points. Please save the attached
Renewable Charging Parameters. Reference the MONOBLOC/AGM column.
Questions: 1. System voltage? 48V DC, correct? 4 in series; 4 parallel strings?
2. You are completely off-grid, correct?
3. Source circuits? You are running PV but do you have a GENSET?
4. Initially, did you setup your charge controller with the attached parameters or did you leave it in the default setting?
5. Do you have an RTS (remote temperature sensor) installed?
6. Who sized and installed your PV and battery system?
Best Regards, Doug Laningham, Domestic - Renewable Energy/Solar, MK Battery - DEKA Solar, Elizabeth, CO, dlaningham(At)mkbattery.com, (720)839-4980
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Van to MK Battery 3:14 PM |
1. System voltage? 48V DC, correct? 4 in series; 4 parallel strings?
Yes. 48V: 4 x 4
2. You are completely off-grid, correct?
Yes, completely off-grid
3. Source circuits? You are running PV but do you have a
GENSET (Engine to generate electricity) ?
Only PV; no generator.
4. Initially, did you setup your charge controller with the attached parameters or did you leave it in the default setting?
default setting
5. Do you have an RTS (remote temperature sensor) installed?
Yes an RTS is plugged into the MX60
6. Who sized and installed your PV and battery system?
Me, with direct guidance from Mark Doppke of Affordable Solar.com and assistance from other pros.
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Van to MK Battery Dec 10, 5:28 PM |
Is anybody going to respond to this?
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MK Battery to Van Dec 11, 6:21 AM |
Van - My apologies! Thank you for the reminder on this.
After looking over your data, I would recommend the following: 16 B-DK-8A27 Deka AGM Batteries Use the charge settings in the attached
Renewable Charging Parameters ........... MONOBLOC/AGM column.
Given that your only source circuit is PV/Solar (no GENSET), it is safe to assume that your batteries are not getting fully charged during the winter months.
Yes. I would recommend an equalization charge following the guidelines in the attached (under equalization stage). In a "partial state-of-charge" application like yours, it is acceptable to occasionally equalize the battery bank to break up sulfation. Best Regards, Doug Laningham
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Van to MK Battery 4:22 PM |
My Absorb Volts is 57.6, so I left it at that.
My Float Volts was 54.4, so I reduced it to 54.2.
My Limit Amps is 60.0. Your specs say "6 times I(sub 20)[1.75vpc]". What is that?
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MK Battery to Van Dec 12, 9:39 AM |
Van - "30% of the C20" means the charge limit is 30% of the 20AH rating for the particular battery
"6 times the I20" means the charge limit is multiplying the 20 hr current rating by 6.
Either way works out to be the same value.
Example 8G31: (Deka/MK Battery 8G31-DEKA Sealed Gel Battery, 12 volt 97.6 AH)
30% of C20: where C20 = 97.6 AH; calculation: .3 x 97.6 = 29.28 A
6 times I20: where I20 = 4.88 A; calculation: 6 x 4.88 = 29.28 A
Hope this helps... Doug Laningham
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Van to MK Battery 11:48 AM |
My Limit Amps is 60.0. Is that correct?
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MK Battery to Van 12:10 PM |
8A27-DEKA (12V, AGM, 92AH at C20 to 1.75vpc) .................. see attached spec.
Assuming: 48V DC (x 4 parallel strings)
TO CALCULATE BULK STAGE:
92AH x .3 = 27.6 amps (max.current)
27.6 x 4 strings = 110.4 amps (max.current) Doug Laningham
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Van to MK Battery 4:29 PM |
"27.6 x 4 strings = 110.4 amps"
So you are saying that I should raise the Limit Amps from 60 to 110.4?
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MK Battery to Van 5:23 PM |
Van - I'm not sure about your particular charge controller but during the BULK STAGE, you can charge up to a maximum of 110.4 amps.
When you say limit, are you saying maximum or minimum? Doug Laningham
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Van to MK Battery 9:59 PM |
It is an Outback MX60. In its CHARGER SETUP screen it now shows:
LIMIT ABSORB FLOAT
Amps Volts Volts
*60.0 57.6 54.2
EXIT --> - +
with 4 soft buttons below the screen for selection (EXIT, -->, -, +).
In
the MX60 Manual, (attached) it says:
"The default charger output current limit setting is 60 amps and is adjustable up to 70 amps. At 70 amps, a 70A or 80A breaker must be used between the battery and the MX60.
Change Absorb and Float set points using this screen if the battery manufacturer's recommendations are different than the default values. Otherwise, see page 79 for suggested recharging voltage set points."
I have a 63A breaker installed.
BTW, I ran the equalization today for 1 hour. Should I run it for a longer period?
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MK Battery to Van Dec 13, 8:18 AM |
Van - I'll call you to discuss! What is your phone number?
A. If your controller only goes up to a max of 70 amps and we are saying a max of 110.4 amps.............potential issue here!!
B. Without a GENSET and charging with PV only, how will you get the batteries fully charged during the winter months?
My suggestion:
I would "definitely" look into a
GENSET (Engine-generator used to generate electricity) (preferably, with auto start capability). Doug Laningham
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MK Battery to Van 9:47 AM |
Van - Regarding your question of EQUALIZE TIME, that's a good starting point at 1 hour.
After a 24 hour settling period, you should check your battery OCV voltages - per battery is ideal; OCV (open circuit voltages), without a load present.
If you cannot disconnect the battery bank, I understand!!
Please call me if you get a minute. Doug Laningham
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Van to MK Battery 11:06 AM |
Hi Doug, We are leaving for the day, so I'll hold off on calling you, especially considering the following:
Remember, from 2007 to 2011, there were no problems. In 2011 it entered the current weak power mode so I replaced my 12 Optimas with 16 Dekas. Since then, while away, everything has worked fine on a minimal load:
24/7 desktop computer plugged into a UPS, 6 cameras including 2 PTZ, 2 water pumps, chest refrigerator.
When we returned in November and began using the microwave, a coffee maker, a compost toilet fan/heater, a tankless water heater, eco bulb lighting - all of which were temporary; as needed, the system could not handle it.
With your guidance and the MX60 manual, I equalized it for one hour, reduced the Float Volts from 54.4 to 54.2 (no clue as to whether that helped or not), and equalized it again for one hour yesterday.
Prior to the above, at night before going to bed, it would show maybe 48 or 47 volts in the bank. In the morning, with almost no load, it was usually down between 41 to 43 volts. Drank cold coffee made the day before. By 10 AM or so, on a sunny day, it would be up to 49 volts and 10 or better Amps where I could get one hot cup of coffee. An hour or 2 later I could let the coffee machine complete its cycle.
The night before last, I activated the equalization process, aware that it would not actually kick in until the bank was full. In the morning, it showed "EQ-MPPT" on the MX60's screen, which I believe means that it is still waiting to kick in.
At about 1 PM, when I guessed that the banks were almost full, I turned off the entire load at the inverter and took a 2 hour nap. My wife was out and about on a spending binge so she did not have to experience the complete loss of power.
When I got up, I turned the load back on at the inverter. It was a sunny day. The MX60 screen did not show "EQ-MPPT" (not 100% sure about that), so I assumed that it had done its thing.
That night, last night, when I retired, it showed 48.8 volts. When I woke up this morning, it showed 48.8 volts. Huh!? I had not seen that in the AM in years.
I microwaved my mug of coffee AND got the 975 watt coffee machine going with a fresh brew. It made it all the way through without a hitch. I plugged the fridge back in, heated my wife some hot water in the electric kettle for her tea, moved into my office and got the computer going. With all that, it had only dropped to 48.4 volts. Wow!
Then my wife heated up a bowl of soup in the new 600 watt microwave and the voltage dropped to the 42 - 43 volt range.
It is 10:38 AM as I type this. The sky is overcast but bright, so it only shows 3.0 Amps, 44.9 Volts, but climbing. I am on the computer. She is doing nothing, electrically.
The odd thing is that the MX60 screen is showing "EQ-MPPT" again.
10:47 AM. 48.9V 4.0A. It is raining now in the high desert, but bright. I am about to take a nap while my wife heads into town (Oh God!). I will probably hit the Inverter switch again. When I wake up I will turn it back on, get a cup of coffee and check the computer. She will probably be back by then. We will then head down the hill to Palm Springs for the afternoon. Hopefully the sun will be out by then and maybe I'll kill the load again, so the thing can complete its equalization.
11:04 AM. 46.6V 2.0A. I have no clue what is going on.
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MK Battery to Van 11:41 AM |
Understood. Ring me when you can. Doug Laningham
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