jrnymn7 wrote:
Well, second actually... first one got cut short due to heavy clouds... and a long ways to go to 'full'.
First, I'd like to thank those who were kind and patient enough to help me along this solar path. As BFL once put it, there's lots to learn about solar. All the debates/discussions over pwm vs. mppt, and such, have proven very enlightening and educational, so thank you!
So, here goes:
Bank... 430Ah, four 6's, ocv @ 12.44v, 74%soc, -111Ah's
Solar... two 140w 12v poly panels, in series, manually tracked, thru 50' of 6awg to a Tracer 3215BN MPPT charge controller and MT50 Remote Monitor.
10:50am:
- clear skies
- Isc at the moment was 'about' 9a (x2). (clamp meter not that reliable)
- Voc 20.6v
10:55am:
at Panels... 7.9a @ 31.2v,
at Bank... 18.9a @ 13.0v
The highest amperage I saw all day was at 11:05am, with 19a to the bank. Mostly in the mid 17's to high 18's up until about 3pm. I was a little surprised, given the conditions. A couple days earlier, under mostly cloudy skies, I saw amps in the high 21's several times... but that may have been an edge of cloud effect thing?
At 1:15pm, I switched over to the Solar30 pwm, and saw a difference of 1a to the bank, 17.3a vs 18.3a, for a 5.5% increase by the mppt controller.
Back on mppt, throughout the afternoon amps tapered to the mid 13's range by 6:40pm, and by 7:40pm, amps to bank were in the high 7's.
(At 5:15, I laid the panels flat, east to west, and saw a difference of 5.4a to the bank, 10.4a vs. 15.8a, for a decrease of 35%, compared to tracked.)
..............
Thanxx!
My "standard" for expected max amps to the 13v battery for aimed panel wattage is based on 130w-8.2a, so 280w should yield 280/130 x 8.2 = 17.66 amps
You got 19a with MPPT and 17.3 with PWM (at different times), so IMO your set-up is working just fine! :)
Choosing the Tracer, with its high Voc limit to let you put 12s in series, was obviously the right choice over the Eco-W with its limitation of 42 or 45 Voc that means it can only do one 24v panel but not two 12s.
I don't fuss about getting to 100% every day on solar. Sometimes you do and often you don't. As long as you get to 100% once in a while and do shallow cycles like 75-95s, you don't need to EQ much if ever. The SG will tell you how that is going.
Good report!
