Solar charge controllers


2004 Fleetwood/Coleman Utah
Oct 10, 2013
Northern Virginia
I need help figuring out what charge controller I should upgrade to and something that won't break the bank. I currently have a cheap mppt 20 amp controller that came with my 100watt solar panel. I can hardly read the screen as it's way too small and wanted room to upgrade to a second panel later down the road. Though the one panel has been doing well so long as I play ring around the campsite with it. I remember reading there was a bluetooth capable charge controller with a special bluetooth dongle sounds cool but the cheapest one I found was also a 20 amp. My needs are pretty simple so I'm probably looking way too into this than I should. Or should I just stick with something simpler and forgo the Bluetooth idea. I was really only hoping to spend $100 or preferably less for the controller.
I have a group 29 deep cycle and bought a 100watt solar panel kit from Amazon. The biggest power draw is only when I use the furnace. Due to me being a wimp in the cold I keep it at 55 and run it through the night. All other power draw is pretty minimal. Fridge is on propane and I run the water pump once a day. If the side kick forgot her battery pack add constant charging of the phone.


Super Active Member
May 21, 2015
Your 20 amp controller should be fine with adding another 100 watt panel. It should be good up to 300 watts total.

Anthony Hitchings

Super Active Member
Gold Supporting Member
Mar 2, 2019
Oakland, California
14V bulk charging at 20A = 280W. Stick with the 20A controller unless your Volt/Amp monitoring suggests that the controller is not delivering all that energy. You can always spend $ later.


Super Active Member
May 21, 2015
If all you want is a better display, there have been a couple of posts about this battery monitor, which has much more functionality than most controller displays. I haven't installed it myself but it's on my list for future upgrades. I found this version which has a longer cable to increase the options for installation locations. It will allow you to monitor the battery whether or not the solar panel is hooked up. Just remember that things like this increase the parasitic draw on your battery.
Last edited:


Mar 3, 2006
I have several PWM controllers. My favorite, the 40A one labeled 'Grape Solar' is the model before the 'comet' in this link. I like free shipping to HomeDepot and 30 day return policy.

Comet, the previous version also was BT and is hit/miss as I've changed pones over the last few years.
Last edited:


freedom is not just another word
Mar 29, 2013
under 300 watts PWM and under a $100 way more under... over 300 watts or adding more panel mppt $ 100 plus higher cost the better but do you really need it big plus with the mppt is they charge 20% faster and they're smarter Santa's comin you know good luck