So Ian, slightly off topic but sort of relevant to your camper roof, but what output do you get from your solar panels? Relative to the rated wattage... I know you've contributed to discussion before and you and I had a chat at Keith's Field last year but this is the first time I've seen your set up. I'm guessing from what we can see that the panels are series wired? So what's the loss in efficiency you have by using different size panels..my understanding is that the smallest panel always drags the system down? I've got a smaller panel to fit on the T3, so I'm currently working out whether to dedicate it just to the starter battery and let the 2 big ones deal with the house battery. All current opinion suggests a balanced system with panels of the same v/w and manufacturer. What do you think?
I'm no expert on solar I have a victron 100 20A mppt charge controller I've been told i can have 290w of panels and to get as close to this as possible so I've got 280w the small one is 30w They are wired in series, I got told ignore wattage its voltage that's important in the uk So as you can see even tho I have low Watts the voltage is good and the victron mppt is the best at harvesting it. The screen shots are from a dull day. Whether the information I was given is correct or not I don't know. Sent from my SM-G981B using Tapatalk
What your charging amounts to depends on the SOC of your batteries, the only way to assess your system properly would be with flattish batteries. You can see your controller is converting your 56.38v x 0.2a = 11.2w to 12.79 x 0.8a = 10.2w - much the same power. Not sure who told you to ignore the power as that's what you're after in the end. Maybe they said exactly the opposite - ignore the voltage as your controller will convert it to 12v and output the same power as it would if you fed it e.g. 24v and more amps. The advantage of high volts/low amps is that you can use thinner cables for the same power. 6V beetles are a good example - a nightmare of fat cables and volt drops.
I have no clue It was the victron group on fb that gave me the information maybe I misunderstood I don't know all I know is it works. Sent from my SM-G981B using Tapatalk
I'm interested in this too - although my panels are wired in parallel rather than series, but they are two different sizes: a 120w and a 60w. The chaps at Photonic Universe suggested that when using a system with unequal panels, a blocking diode would prevent backflow of power https://www.photonicuniverse.com/en...nels-to-the-same-solar-charge-controller.html Does it work? Who knows! Next time the sun comes out, I'll have a proper look to see what it's all doing - rather than just being happy that nothing has gone flat!
Plenty done over the weekend I've not fitted the gas struts yet so holding the roof up with my roller poles. We bought the canvas from proud to pop But it's 4" too long so it's a bit saggy at the ends Thing is when I fitted the Devon pop top that was too long also and it was from the same company. @Zed you were right about the roof it's a struggle to get it to close don't know if it's because the material is new or the top isn't deep enough the fabric is very stiff So hopefully it'll soften up. But I'm happy with it so far apart from it being 4" to long. Still plenty to do Sent from my SM-G981B using Tapatalk
I don't really know if this is correct, but just read it somewhere and nobody is arguing with it. You can only combine panels in series if they have the same or close Imp (max power current) or in parallel if they have the same or close Vmp (max power voltage). If they do not match then the combined set up will not harvest both panels and you could end up worse off as the lowest rated panel could pull the max power down to match it.
Interesting. I'll have a play around with disconnecting each of them and seeing what the voltage and amps does. No point having the smaller one, thinking I'm getting 180w if all it's doing is dragging the 120w panel down. I did talk it over with Photonic Universe when setting up, but I may have misinterpreted what they said. I'll have a look.
Loving it so far. Not sure where your at with it but the baggies on the overhang is due to the side not pushing out far enough. When you sa it’s too bi… in which direction? Length? Not sure how to rectify that!
Yes mate the length is 4" to long But I didn't realise until one side was stapled in. I didn't think to measure it beforehand as you just expect it to be right. The overhang is pushed out as far as the canvas will allow. I've managed to tighten up the sides a bit since this photo but trying to loose the extra few inches is difficult as it unfortunately creates baginess. Sent from my SM-G981B using Tapatalk
Still not quite finished but should be all ready for Techenders. Sent from my SM-G981B using Tapatalk
If you have two paralell solar panels, ideally they are combined with diodes as a shaded panel will drag down an illuminated panel. If both are reasonably well illuminated then the voltages will balance out and the power should be higher more like the sum of the two panels. If they are in series the parallel bypass diodes built into panels let the current from an illuminated or high power panel reach the charger, the voltage from the shaded or lower power rated panel becomes zero. A small panel in series is just three diodes dropping about 2 volts from the big panel.. But you wont see the full output of the panels unless the battery voltage is well below 13.8 to 14.4 volts . The charger will be backing off to protect the battery.
New panels are on @mikedjames Wired in parallel I'll take some better pictures tomorrow. Sent from my SM-G981B using Tapatalk
