solar pre-wired questions
Our new rv has an outdoor two pin plug-in for solar. What do I need to take advantage of it? What are it's benefits and limitations? We don't currently have any panels.
Forum Discussion
- I wondered if he was referring to controller to battery wire size or cost?
3 tons wrote:
KD4UPL wrote:
#10 is a fine size if not overkill. Using an 100 amp Outback FM100 or Magnum PT-100 as an example you could hook up well over 1,000 watts of solar panels.
Sorry, not practical…
3 tons
What are you talking about? I probably install one of these a month on average.
Nobody doing any serious solar work even thinks about using a charge controller that isn't an MPPT model. PWM controllers are like black and white TVs and floppy disks.KD4UPL wrote:
3 tons wrote:
KD4UPL wrote:
#10 is a fine size if not overkill. Using an 100 amp Outback FM100 or Magnum PT-100 as an example you could hook up well over 1,000 watts of solar panels.
Sorry, not practical…
3 tons
What are you talking about? I probably install one of these a month on average.
Nobody doing any serious solar work even thinks about using a charge controller that isn't an MPPT model. PWM controllers are like black and white TVs and floppy disks.
yup and all the manufactures still use those black and white tv's when they install a system in the new camper. smaller controller that is easier to mount to a wall is what I figure.pianotuna wrote:
pbitschura wrote:
3 tons wrote:
As has been said, the wiring may not be heavy enough for a substantial system. I see little portable set ups. Can I then use this plug in for a battery maintainer to top it off while boondocking, maybe 100 watts or so? These, I believe come with a charge controller for a minimal system.pbitschura wrote:
Our new rv has an outdoor two pin plug-in for solar. What do I need to take advantage of it? What are it's benefits and limitations? We don't currently have any panels.
Most factory solar wiring is kinda minimalist in AWG wire gauge - you’ll be lucky if it’s #10 AWG gauge, and a lengthy roundtrip wire run (+ & -) adds to overall resistance (meaning excessive voltage drop - ugg…)…As such (if wiring panels in parallel) consider limiting your panel wattage to about 200w or so, or if more wattage is desired, consider wiring the panels in series (to help compensate for small’ish wire gauge) using an MPPT type controller that’ll exploit the higher voltage - or add a separate wiring run (of sufficiently gauge) from the roof-top down…This can often be accomplished by snaking the new wire down through the rooftop refer vent..
3 tons
A pwm system runs "at the battery voltage". They are basically a switch that closes and opens. As the battery charges they shut off and on with the on time getting shorter and shorter.
Depending on the size of the bank 100 watts may be fine to run directly to a good sized bank. This is not recommended.
Get a good MPPT controller and use the highest voltage on the panel input side of the controller alows.
This allows the use of residential panels which are cheaper per watt.
My personal preference is for polycrystalline. Why? Because in the real world they do better if there is any shade--and since this system is panels in series that's a big thing.
I think you need to do a bit of reading on Polly Vs mono. here I'll sum it up for you
"Polycrystalline panels have lower efficiency rates typically in the 13-16% range. Monocrystalline panels have higher efficiencies in the range of 15-20%.
Because of the lower efficiency rate they are not as space-efficient since they produce less power per square foot.
Polycrystalline panels tend to have lower heat tolerance than monocrystalline solar panels and perform slightly worse than monocrystalline solar panels in high temperatures.
Heat can affect not only the performance of polycrystalline solar panels but is projected to substantially shorten their lifespan.
Polycrystalline panels are also less efficient in low-light condition."
in no way is a polly panel better than a Mono except in how much you pay for the panel.
I'm almost wondering if you're confusing polly for a split cell design as they are more efficient than solid cell in shading.
Steve3 tons wrote:
KD4UPL wrote:
#10 is a fine size if not overkill. Using an 100 amp Outback FM100 or Magnum PT-100 as an example you could hook up well over 1,000 watts of solar panels.
Sorry, not practical…
3 tons
What are you talking about? I probably install one of these a month on average.
Nobody doing any serious solar work even thinks about using a charge controller that isn't an MPPT model. PWM controllers are like black and white TVs and floppy disks.pbitschura wrote:
3 tons wrote:
As has been said, the wiring may not be heavy enough for a substantial system. I see little portable set ups. Can I then use this plug in for a battery maintainer to top it off while boondocking, maybe 100 watts or so? These, I believe come with a charge controller for a minimal system.pbitschura wrote:
Our new rv has an outdoor two pin plug-in for solar. What do I need to take advantage of it? What are it's benefits and limitations? We don't currently have any panels.
Most factory solar wiring is kinda minimalist in AWG wire gauge - you’ll be lucky if it’s #10 AWG gauge, and a lengthy roundtrip wire run (+ & -) adds to overall resistance (meaning excessive voltage drop - ugg…)…As such (if wiring panels in parallel) consider limiting your panel wattage to about 200w or so, or if more wattage is desired, consider wiring the panels in series (to help compensate for small’ish wire gauge) using an MPPT type controller that’ll exploit the higher voltage - or add a separate wiring run (of sufficiently gauge) from the roof-top down…This can often be accomplished by snaking the new wire down through the rooftop refer vent..
3 tons
A pwm system runs "at the battery voltage". They are basically a switch that closes and opens. As the battery charges they shut off and on with the on time getting shorter and shorter.
Depending on the size of the bank 100 watts may be fine to run directly to a good sized bank. This is not recommended.
Get a good MPPT controller and use the highest voltage on the panel input side of the controller alows.
This allows the use of residential panels which are cheaper per watt.
My personal preference is for polycrystalline. Why? Because in the real world they do better if there is any shade--and since this system is panels in series that's a big thing.KD4UPL wrote:
#10 is a fine size if not overkill. Using an 100 amp Outback FM100 or Magnum PT-100 as an example you could hook up well over 1,000 watts of solar panels.
Sorry, not practical…
3 tons- Be careful about some of these answers. For example, most solar controllers put out about 14.5 volts to the batteries. At 14.5 volts, 1000 watts would be about 70 amps, way too much for #10 wire. Now, if you are wiring panels in series and have them sending 40 volts to the SOLAR CONTROLLER, then that is about 24 amps, and is OK. But the 14 volts from the controller to the batteries is not, without reducing the amperage available. That is why my solar controller can not put out more than 30 amps, max, at 14 volts. That is safe for #10 wire.
- #10 is a fine size if not overkill. Using an 100 amp Outback FM100 or Magnum PT-100 as an example you could hook up well over 1,000 watts of solar panels.
- Probably, but if you're now sure just wire the controller directly to the battery.
For most 100W is inadequate for boondocking but OK for unused RV (storage) battery maintenance.
Only you can answer your question with an assessment of your needs.
