Connecting two solar panels with different watts through one battery controller

New to the solar power world. I have two coleman solar panels, 1 40W and 1 100W. The 40W comes with a battery controller while the 100W does not and seems to be more heavy duty, intended for fixed installation. I would like to find 1 battery controller that I could plug both panels into, that would than feed my two 12V batteries within my RV. If anyone could recommend a fairly straight forward option, that's not going to break the bank, that would be appreciated!
Comments
You would have the choice of removing the charge controller from the 40 watt panel, and paralleling with the 100 Watt panel (assuming Vmp voltages are a "match"), and get a new/larger PWM controller... Roughly:
- 140 Watts / 17.5 volts Vmp = 8 amps...
So a 10 amp or larger PWM controller would be appropriate. Install the controller near the battery bank (short/"heavy" wire from charge controller to battery bank is best). The longer wire run(s) should be from the controller to the solar panels.When connecting charge controllers, connect them to the battery bank first, then the solar array. And disconnect array first, then the battery bank. It is possible to "confuse" a charge controller if you connect to the solar panels first--The controllers are designed to take their operating voltage (for booting the microprocessor, determining bank voltage, etc.) from the battery bank.
-Bill
Bill, thank you for the feedback, very helpful.
I double checked the VMP and based on my calculation (140 Watts / 17.1 volts = 8.2 amps), the 10 amp controller should work well.
I found a 10 amp Wanderer on amazon that appears to be well suited for my application as a reasonable price point.
https://www.amazon.ca/Renogy-Wanderer-Amp-12V-24V/dp/B07NPDWZJ7/ref=sr_1_3?dchild=1&keywords=wander+battery+controller&qid=1591191890&s=lawn-garden&sr=1-3
Appears I will have some wiring / connector configuration to deal with but this looks to be fairly straight forward.
If you have any other tips or better options for a controller, please let me know.
Much appreciated!
There are lots of other questions... What are your loads, the size and type of batteries, where you will be using solar, will you be using a genset too, are you trying to use solar for all your power needs, using fuses/breakers to protect hour DC wiring from short circuits, etc.
It is very common for folks to underestimate their loads, and over estimate the energy generated by solar... And end up with short battery life from undercharging and over discharging.
-Bill
http://www.solarelectricityhandbook.com/solar-irradiance.html
Toronto
Measured in kWh/m2/day onto a horizontal surface:Average Solar Insolation figures
Have fun!
-Bill