Western WRM15 dualB Solar Charge Controller Review

Price: can't remember, bought in 201x Manufacturer page

This device was bought a long time ago, but due to problems getting the app to even open, it has not been properly configured for several years.

For some reason, we could never get it to work with either a Fairphone 2 or 3. Raising a ticket with support was unhelpful - they basically said "just try it with another phone", which we did and it still didn't open.

No attempt was made to request any log files from us, nor were we given a development/debug version to help with the troubleshooting process.

A few months later after asking for an update, they said a new version was available which "should fix the problem", but no changelog was provided, nor any explanation. This version was no better.

Since getting a Samsung S20 Ultra 5G (Android 13), the app now works, and we could configure the various settings for a LiFePO4 battery, as the default is for Lead Acid, which meant our battery was never charged fully.

An RS-485 connection is available via some terminal connections, but I never got around to trying it as my Modbus/RS-485 knowledge is limited!

The manual is quite useful, and explains the various LEDs. The "Charge" LED fliashes more often the more charge that is going into the battery.

The device logs kWH generated from the panels, and used via the "lightbulb" output terminals, which is useful.

Android App interface for v2.3.1:

A previous version worked in landscape only, and wasn't as readable.

Pros

• One of the few devices available that will charge two batteries from one controller
• App updated from time to time
• Most recent Android app update to v2.3.1 (2026) has a much better interface than previous version
• Bluetooth adapter is on a 2m cable, so it can be placed away from the charge controller for a better signal
• Comes with a 5y warranty
• Made in the EU (Italy)
• Can work with 12v and 24v batteries
• Supports LiFePO4 batteries and various charging/voltage settings
• Has graphs showing historical charging rate and voltages
• Solid metal housing

Cons

• Seems picky about Android devices
• No way of configuring the device without the app
• No display
• Support unhelpful
• Android App details show several mb of "mobile data" used for no reason
• Can't pair the bluetooth connection, so "Location" needs to be enabled before the device can be detected on Android every time the app is opened
• Slow to receive historical data when opening the app, but this could be a Bluetooth limitation
• Only supports up to 250W@12V or 500W@24V of solar

Conclusion

The device is reliable, as it has been in place for several years, although only recently has it be been configured correctly.

Android App is well designed, and gives realtime updates of charging state.

I used it to give an example of how minor shading affects charging, which you can see below. It is a bit difficult to see the display in the sunlight, so you may need to watch it full-screen.

it's a shame you cannot pair the device, so you have to enable both Bluetooth and Location every time you want to connect to it, which slows up the process if you just want a quick look at the charging status.

Due to the "Pros" listed above (and finally having a working Android app), it is not a bad choice for small systems.