Matching solar panel to MPPT to battery

MrSinbad

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May 20, 2022
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Hi all. Just registered and I have some newbie questions... Apologies if this has been asked and answered.

I bought this solar panel from BHU because of the low price and I'm looking to have backup power for my new ("efficient") refrigerator and laptop workstation with the following specs:

Solyndra 220W Solar Panel
DC Electrical Characteristics
• STC Power Rating 210W
• PTC Power Rating 194.2W 1
• STC Power per unit of area 7.9W/ft2 (84.5W/m2)
• Peak Efficiency 8.45%
• Power Tolerances -4%/+4%
• Number of Cells data not available
• Nominal Voltage not applicable
• Imp 2.21A
• Vmp 95.1V
• Isc 2.36A
• Voc 125.3V
• NOCT 44°C
• Temp. Coefficient of Power -0.38%/K
• Temp. Coefficient of Voltage -0.351V/K
• Series Fuse Rating 24A
• Maximum System Voltage 1000V
Mechanical Characteristics
* Type Cylindrical CIGS​
* Output Terminal Type Tyco SolarLok Connector MC4​
* Frame Color Black​
* Length 89.8in (2,280mm)​
* Width 42.9in (1,090mm)​
* Depth 1.4in (36mm)​
* Weight 70.1lb (31.8kg)​
Looking to connect it with a:
  • EPEVER MPPT Solar Charge Controller Maximum input voltage (open circuit voltage): 150V Tracer AN Series in either 30, 40, 50, or 60 Amp or
  • Tracer BN Series 150V PV Input with no LCD screen (only 40 Amp max?) or more.
Then connect to (already purchased) a battery and separate 300W pure sine wave inverter:
(2) 24v 24ah 621.6wh 21x SPIM08HP (could be wired parallel or series), or
(1) K2 12.8v 138.53ah 1789wh Lifepo4 Module or
(2) BMW OEM 4s 14.8v 75ah 1.11kWh Battery Module (could be wired parallel or series)
With each battery, I would deplete one battery in one day for the fridge. For my computer workstation, I would have more than a week of autonomy, not including one LED light and fan at night.

Questions:
1) What size MPPT controller should I buy? 30, 40, 50, 60 Amp model?
2) If the MPPT says, "Maximum input voltage (open circuit voltage): 150V," is that high enough to meet the output from the solar panel? (Voc 125.3V < 150V = OK?)
3) The Mechanical Specs says "Output Terminal Type Tyco SolarLok Connector MC4." Does that imply there is a junction box (or no junction box) with terminals for MC4 wire connections, or it implies there are MC4 wires already connected?
4) Does the EPEVER AN and BN series have MC4 terminals, or regular screw and pinch terminals? If no MC4 terminals, then I I have to cut off the MC4 connector and strip the wire for the MPPT?
5) Any other comments/suggestions you would make?

Thanks for your time and patience.
Ed
 

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
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Location
USA
1) What size MPPT controller should I buy? 30, 40, 50, 60 Amp model?
What system voltage will you have? Your battery listing is odd. You seem to have 2 24V batteries, 1 12.8V battery, and 2 14.8V batteries.

Do you plan to add more solar? With a single 220W solar panel you only need a 20A controller on a 12V system or a 10A controller on a 24V system. If you plan to add more solar then of course you need a higher amperage model. The basic calculation is total panel wattage divided by system voltage. That gives you the rough charge current which is the amperage rating of most solar charge controllers.

2) If the MPPT says, "Maximum input voltage (open circuit voltage): 150V," is that high enough to meet the output from the solar panel? (Voc 125.3V < 150V = OK?)
Voc goes up in the cold. Your panel would reach 150V at about -24ºF/-31ºC so unless you might ever see lower temperatures then your will be fine with that panel on that controller.
 

MrSinbad

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Joined
May 20, 2022
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6
Yes indeed, I have two 24V Lion batteries, one 12.8 V LiFePo4, and two 14.8V Lion battery. I bought them at different when they were on sale.

Not really planning to add any more solar panels (but I'm toying with the idea of looking for a higher wattage single panel) as I will be putting the panel in the backyard or on the side of my house (on my 50' X 100' lot), and my wife will absolutely kill me. Thanks for the basic calculation.

Thanks for confirming the Voc for me. I think I will look for a 30A 150Voc MPPT controller in case I add capacity. Any mfg and/or model you would suggest?
 

Supervstech

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Which of those batteries are you planning on powering with solar? Because they are all incompatible.
 

MrSinbad

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May 20, 2022
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My strategy is to switch the 3 different batteries in and out as needed. Thus, the two SPIM08HP could be charged in parallel or in series. The LiFePo battery will be charged by itself as a 12V battery. And the two BMW LiPo batteries will probably be charged in series at 24V. Yes, looks all sorts of mixed up and confused in direction, but my purchases were dictated by what I can afford at the time of my purchase. Sorry.

I understand, I can squeeze more watts into a battery pack if I charge them at 24V rather than 12V. Is that correct?
 

MrSinbad

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May 20, 2022
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I’m just using the solar panel as a charger to charge the batteries. Once charged, I’ll put the batteries away until I need them. If I use any of the batteries, I’ll take out the solar panel and recharge the battery. Hope it’s more clear now
 

Supervstech

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My strategy is to switch the 3 different batteries in and out as needed. Thus, the two SPIM08HP could be charged in parallel or in series. The LiFePo battery will be charged by itself as a 12V battery. And the two BMW LiPo batteries will probably be charged in series at 24V. Yes, looks all sorts of mixed up and confused in direction, but my purchases were dictated by what I can afford at the time of my purchase. Sorry.

I understand, I can squeeze more watts into a battery pack if I charge them at 24V rather than 12V. Is that correct?
Watts are the same regardless of the voltage arrangement.

I am curious how you are using a single inverter with three different battery styles…
 

MrSinbad

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May 20, 2022
Messages
6
The LiFePo4 and the BMW batteries (individually) can wired up to a 12v inverter. The SPIM08HP may need to be required into 12V packs or if I’m too lazy, just buy a 24V inverter.
 

MrSinbad

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May 20, 2022
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I know this sounds very ineligent and Jerry rigged. Thanks so much for ur patience.
 
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