Smkettner, maybe I am better off to run 4 x 135W panels in parallel. That way, for those times when one is partially shaded, I will still have the full, output from the remaining 3 panels. I think I will have to modify the wiring by placing a joiner box on the roof then run big cable (#4) from the joiner box down to the controller to minimize the drop in voltage. The main reason that I originally connected them in series was because I could run from the panels all the way to the controller via the #10 gauge MC4 leads with a 24 vdc supply. Since I am transferring the panels to my new coach, now is the time to make the wiring upgrade. With #4 from the roof top down to the controller I think I preserve all my options. Your opinion?
Westend, thanks for the feedback. My thought was to parallel the 245W 24 volt panel with the existing pair of in series 135's which would still give me two 24volt modules feeding the 24 vdc controller. I may be able to find space for another pair of Kyocera 140's but as I mentioned to smkettner I will encounter partial shading of one of the panels caused by the AC. If the mppt controller negates the adverse affect of this shading then maybe that is not an issue.
Does your controller find multiple power points? With those voltage specs it looks like the new panel would have to parallel to the other 2 that are in series to stay in spec for what the controller can handle.
The second panel you are looking at has a closer Vmpp to 2x your existing panels. Closer MPPs means the system will make better power across the different spec panels because each can run closer to its optimum voltage when run together.
Hi Tech, why would l need to run them in series? With the two 135'sin series giving me a nominal 24 VDC plus a 245Watt additional panel (nominal 24 VDC), hooked in series would give me 48 vdc, NO.?
2oldman, shade in moses lake should be a welcome topic. I am sitting in LaMesa's RV lot in Phoenix and you could fry eggs on the pavement so shade would be welcome here too. However, shade on the solar panels may be a horse of a different color. I read an artcle on the Nortern Arizona Wind and Sun forum which convinced me that partial shade is a non issue when you have an mppt controller. What say you?....as Bill O'Reilly always says.
Thanks smkettner. I thought about 2 more 135's or 140' s but have not graphed out my roof to see if I can get that much area without running in to partial shading from the AC's or the vent covers.. Would you still recommend the two 140's if partial shading would detrimentally affect one of the two?
On my RV roof I presently have 2 Kyocera 135 W panels, flat mounted, hooked in series, feeding to my Blue Sky Solar Boost 3024iL charge controller. I want to add more panels to my array. The simplest seemed to me to be to add a Kyocera 215 W panel or a 245 W panel but I do not want to owerpower my charge controller.
The two 135 W panels have the following specs: Vmp 17.7 , Imp 7.9 A, Voc 22.1, Isc 8.7A
The 215 W panel has the following specs: Vmp26.6, Imp 8.1A, Voc 33.2, Isc 8.8 A.
The 245 W panel has the following specs: Vmp 29.8, Imp 8.2 A, Voc 36.9, Isc 8.9 A.
The Charge Controller specs are: Output Current Rating 30A/40A, the Nominal Battery Voltage is 12/24 VDC, and the PV input max is 57VDC.
Since the two 135 Watt panels are hooked in series I am not sure how that affects the load on the charge controller.
Can someone who understands all this give me some guidance as to what maximum size panel I can add without exceeding the capacity of the controller?
Thanks for your feedback folks.
My 1994 Suzuki Sidekick has 472,000 Kms on it and we need to shop for a new unit for towing behind our motorhome. I have read the many posts om this forum and there are numerous models that people inquire about, mostly vehicles they already own and wonder about towing them. It there a reliable resource that lists all newer makes and models of vehicles with automatic transmissions that are towable four wheels on the road without modification of the drive train In other words, "as is". Since we use the vehicle as a second unit I wanted to find someting in the 2010 or newer range. I was hoping to have a list of potentially suitable units for when I hit the car lots rather than having to check out the tow ability after the fact. Any help?
I have a new Samsung 10.1 tablet which only gets WIFI. It occured to me that this light weight device would make a decent GPS for operation in my motorhome if only I could figure out how to achieve same. I presently use Delormes Street Atlas on my laptop and their satellite detector that plugs into my USB port.Has anyone figured out how this tablet can be incorporated into a GPS setup?