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BFL13's avatar
BFL13
Explorer II
Apr 01, 2014

Eco-Worthy MPPT and Solar30 PWM Test

Did a quick backyard test of my two solar controllers using the actual trailer wiring etc as intended for camping with solar later this month. Got some blue sky, no clouds.

The Eco-W on the 230w panel showed the same amps reading on the controller readout as on the solar part of the Trimetric amps, so that checks out. At the time I was getting 14 amps on the Eco-W and with -19 amps of lights on the Trimetric this dropped (rose) to -5 amps when the solar was turned on.

I hope to get more amps from the 230w/EcoW while camping and get the panel pointed right etc. but that is what I got in today's test.

For fun, I swapped to the 12v 130w panel. In this case panel Isc was 8 amps and the EcoW was showing 9 amps, so that checks out too for what MPPT should be doing. Salvo got the same sort of result with his MPPT- 8.5 vs 8. Of course he was using a mere BlueSky ISTR, so I got an extra 1/2 amp using the superior Eco-W :)

Now the Solar30 with the 130. I have found my particular Solor30's readout is off a bit for voltage so it reads 0.2 low. The voltage setting for its high set point or float has an index error too, where if you want 14.8 you have to set 14.4. Once you find these errors, you can keep applying them so it is no big deal but you do need to do some comparison calibrating first.

So that is what I tried today on the amps reading. The panel Isc was still 8 amps, but the Solar30 amps said 7.7a I was not able to get the Trimetric onto that with my split bank for a third opinion, but I will eventually. Meanwhile, I am going to ASSume the amps also read low and the difference was not in the wiring.

Of course this means the AH counter on the Solar30 may also be out. It will take a while camping and building up some data to get the index errors figured out, but it appears once you have those, you can use the readouts because they are consistent.

According to the calculator here, we are not quite up to STC insolation yet this early in the year, so I will blame that for now!

http://pveducation.org/pvcdrom/properties-of-sunlight/calculation-of-solar-insolation

Never mind the 130w did ok--but also you have this heat thing that hurts the voltage for MPPT on the 230 but raises the Isc of the 130

With the 130 getting 8, the 230 should have been getting
230/130 x 8 = 14.15 (which it did) but also something for MPPT "advantage." The 130 advantage on MPPT was 9/8 so 9/8 x 14.15 = 15.9 so naturally I feel ripped off by this whole MPPT farce and demand my 16 amps I didn't get!!! :) Not really, I still have hopes once set up better later in the year..

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