Newbie question about making 3-to-1 parrallel mc4 connectors

[tb144050]

I do like that alot. I hope you dont mind if I do mine the exact same way. It's time to shop for more parts and get them here asap.
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Btw...my battery bank and panels are safely disconnected when I am not benchtesting something. It is not operational unsupervised, and I do prefer the battery bank to remain "not fully charged" so I can benchtest without the need to hook up a load. After panels and wiring are successfully completed, I intend to re-mount the panels properly (and at better angle) and hide more of the wiring.
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My wire lengths from panels to PWN cc (or multiple cc''s) will also be shortened by 5-10 feet when I install a proper box on the wall instead of benchtesting from inside a rubbermaid container that is further under the carport than necessary. (This is another "incomplete portion" that contributes to the need to keep disconnected unless benchtesting.

[tb144050]

Where do you get your boxes and fuse blocks? On breaks at work tonight, I have been searching for those screw-down fuse blocks and can't find anything less than 12-fuse blocks for $16.

[PNPmacnab]

I rolled my own system with a uno micro. My excess PV power is used to heat water. Array is only 900W and for 3 months haven't had to fire up the propane. The nice thing about this is you can write a test routine to operate the PWM power levels to the heater and test your panels to find max power at power point. Can't tell you how handy this is. Anyone interested in micros? You can still accomplish a lot with those cheapo recording watt meters like GT POWER on ebay for only $10.

[SunEagle]

The box came from Home Depot. The fuse holders and fuses came from either amazon or eBay. I pretty much got most of the hardware from those sites including the cabling with the MC4 connectors.

[tb144050]

Ok. Given limited time to test it this morning (because I worked last night, have to work again tonight, and it is forecasted to rain the next 2 days), I monitored what I could in the 1 hour of sunlight before I had to disconnect it and come in to sleep. More testing, observation, and learning are in my future.....but all seems to be working better on a SUNNY day. I will proceed to improve the temporary setup toward its permanent goals.....but here is what I have noticed (and learned):
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Each panel independently (and each possible combination of parallel panels) produces Voc of about 20.4v ~ 20.8v
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Each panel independently produces an average of 13.0 ~ 13.4v .....and...... 1.2 ~ 2.5 amps with minimal cloudiness (mostly sunny) and NO LOAD on the battery bank.
------As I combined more panels in parallel (while battery bank disconnected by breaker each time)....the total amperage increased at an expected rate, up to a total of 4.5 ~ 5.5 amps for all 4 panels at 14.1v.
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Suspecting that the PWM cc might be "trickle-charging" the battery bank, I applied a LOAD directly to the battery bank. LOAD is a 300w 12vdc heater. WITH LOAD ON the battery bank, current(I) through the shunt on the "PANEL INPUT NEG(-)" increased to a max of 15 amps @ 13.3v.
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After running the LOAD for 5 minutes, I disconnected the LOAD OFF.....and.....saw some better charging "specs" than I first saw BEFORE the LOAD was connected: 1.9 ~ 2.5 amps ....@ 19.4v...........and the battery bank was at 13.1v according to the PWM cc.
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Overall, I suspect that everything might be functioning properly, even the other (cloudy) day given the following conditions:
battery bank might be more charged than I expected all along (until I applied the load)....
it WAS cloudy the other day.....
panels are not at best angle.....(about 135 degrees to sun.....not 90 degrees to directly face the sun).......
Even under LOAD, I did not achieve the expected 20~22 MAX amps....but....bad angle and PWM cc are suspected to blame.
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Rainy days coming up, but I will be ordering the next components to bring this installation further along. Any professional diagnosis of the measurements I provided (versus the conditions described) are welcome. Thanks for all the previous help, and I apologize if I took valuable time due to "battery bank not very low," "not the best angle," and/or "cloudy day" all contributing to the terribly low and unusual results the other day. Thanks again and thanks in advance!!