Yes, the SmartRelay is a perfect companion and it will be functional in no time.
First make sure the SmartRelay is powered by your battery pack by connecting the – of the pack to pin 1 of the SmartRelay and the + of the pack to pin 4 of the SmartRelay connector.
Switch a load
Wire the + of your battery pack to the SmartBMS OUT board Load connector pin 2. Also add a wire from pin 3 to the SmartRelay input 1 or 2, depending on which relay you want to use of the SmartRelay block.
Switch a charger
Wire the + of your battery pack to the SmartBMS OUT board Charge connector pin 2. Also add a wire from pin 1 to the SmartRelay input 1 or 2, depending on which relay you want to use of the SmartRelay block.