Adding another solar panel

[JAMES JAKE]

Hello Folks
I have one Go Power 100W solar panel on my RV so is it safe to use a different manufactures solar panel along with existing panel?
My solar panel = GoPower 100W
Future install = HQST 100w

 

[HRTKD]

See this video:

It's by SolarQueen, who is a forum member.

You're probably OK since they're both 100w. But look at the differences in voltage and amperage. Which solar charge controller are you using? If it's a PWM, you may need to parallel the new panel to the existing panel instead of in series.

 

[JAMES JAKE]

Thanks HRTKD

​

 

[JAMES JAKE]

I bought this one - https://www.amazon.com/gp/product/B0811F75H3/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

A possible change of plans though, I think I'm gonna remove my existing "Go Power 100W solar panel" and replace it with this 200W panel, that is if the connections are the same.

Amazon.com

Also. I will add on a voltage monitor since the controller will be in a cabinet and it will probably be the MT50 -

Amazon.com : EPEVER MT50 Remote Meter LCD Screen Display, Monitor and Set Data of EPEVER TracerAN TRIRON N Tracer-BN VS LS-B Series MPPT&PWM Solar Charge Controller : Garden & Outdoor

Amazon.com : EPEVER MT50 Remote Meter LCD Screen Display, Monitor and Set Data of EPEVER TracerAN TRIRON N Tracer-BN VS LS-B Series MPPT&PWM Solar Charge Controller : Garden & Outdoor

www.amazon.com

 

[MichaelK]

I would stop buying 100W 12V panels completely. Buying off of Craigslist, you're likely to get two 250W grid-tie panels for the same amount of money as 1 single 12V panel.

Since you have an MPPT controller, the controller will transform the raw high voltage solar down to the voltage the battery wants.

Are the panels going to be laying flat on the roof? If so, expect them not to put out more than 75% of their rated output. With that 30A controller, you could put in (30A X 13V charging)/0.75= 520W of panels. Call that two 260W panels. I bought some of those for a neighbor last year for 62$ each.

 

[12VoltInstalls]

The one thing about 100W panels is you can scale up 100- or 200W at a time. Decent 2x 100W kits w/ pwm and cables are moderately inexpensive but easy to start, and you can go 5P for 500W

However if you know you’re going 1kW right away it starts not making sense.

Anyways, at 500W+ an MPPT usually gets more out of the panels, so as ^ above a pair of 250W panels is right there. Good mppt’s will let you harvest at 24V or 48V and charge at 12/24/48 depending on your battery plan and types.

I say all that basically because having separate strings facing different directions rather than one or two panels seems to have benefited my system a lot. 200W panel can do surprisingly well, but in use my 400W 2S2P “feels” like I have triple the power (I don’t, I just added a few hours of optimal insolation with two 200W strings)

Just thoughts. Ymmv but 400W was a huge improvement over 200W for me