Renogy BT-2 Bluetooth Dongle for the DCC50S

Written by
Mike Reyher
Date published
June 1, 2020

This is a quick first impression of the Renogy BT-2 dongle to be used with the Renogy DCC50S charge controller.


Renogy BT-2 Bluetooth Module

The idea behind this thing to be to able to monitor and adjust settings for your house battery charging system which in this case is the Renogy DCC50S.


Renogy DCC50S DC to DC and Solar Charge Controller

I ordered the BT-2 direct from Renogy and it arrived via FedEx/USPS in under a week. Directions are rather terse and Chinglish in nature. It starts to become clear that is device is not specific to the DCC50S and really developed for use with their more solar specific product. That impression become reinforced with the user experience with the app.

Installation is much like plugging into an Ethernet port with an RJ-45 plug that goes into the left side of the charge controller. Upon plugging in the Bluetooth dongle powers up as indicated by a green light and a blue light indicates the device is ready to connect to the app.

I swung over to the Google app store and searched for "Renogy BT" as directed in the manual and installed the app on my phone. When the app started up it comes up in the monitor screen and gave me a blank stare with no values. Obviously I had to connect to the BT-2 and I hit the "+" in the upper right corner of the interface. I was then presented with a cryptic list of devices to connect to. I chose the one that started with BT and got lucky. The monitor screen began to show some voltages and current information but not really what I expected.


The above screen is with the engine started and the red alternator light indicating that the charger is drawing current from the alternator. The first section is titled "Solar" and showing .6v which is curious since there is no solar panel connected at this time. But it does show no current. I wonder if it is possible to have voltage with zero current. The next section is "Battery" and it say the status is "Normal". I don't know what that means other than it doesn't sound bad and there is nothing to indicate any other possible states. Below that is a panel/section labeled "Load". Right now there is no load on the system as everything is turned off other than the charger and a batter monitor but when the alternator engaged the current value jumped up and hovered in the 18 to 20A range. So I am guessing that is the charge rate from the alternator. The toggle looking thing next to the "Load" label does not react to any input. Status is "Close" Hmmm. Close to what? The 230W is close to 12.5v x 18.35A so that makes sense, whatever we are looking at. I am guessing the charge rate. Which is not the "load".


The next screen that is available is "Record" which seems to pull up data from the connected device and display it here on a day by day basis. Some of the values are obvious as to what they are and others are downright mysterious much of which looks like some of these labels are for information not pertinent to the function of the DCC50S or that it would have any way of measuring. Some values I believe to be misleading simply due to the context in which the app presents them.


This is the settings screen. Again, a lot of promise but it looks more like a game of fill in the blank as it tries to take data from the device and map it into this table. The labels for the value seem out of place for the device we are trying to understand and manage.


Over in the "Record" section there are some graphs that expose the absurdity of how it is trying to make some data fit into an app not designed to support the device so you end up with mostly nonsense.

Update: 6/28/2020

OK... so.. evidently I must have hurt the devices feelings with that last comment as it has stopped revealing data from the charger. The BT-2 power indicator is lit and the the Bluetooth indicator (blue) light shows connected when I ask the app to connect but no data is actually accessible from the app. I don't know if there was an update or what has happened but it has rendered the BT-2 completely useless and I am going to have to pursue things through Renogy's support channels so I will have an opportunity to check that out and I will report back.

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