Any Roku remote that must be paired to the Roku it is to control connects via WiFi direct. This makes it vulnerable to conflicts when a congested WiFi channel is being used that makes it overwork by having to separating data packets meant for it from all the other traffic and interference on that channel. This is especially a problem if using the 2.4 GHz channel that is shared with smart household appliances, thermostats, etc., and receives interference from microwave ovens.
If you have access to your router's setup, try configuring it to use a different WiFi channel to see if this helps the situation. If you are connecting in the crowded 2.4 GHz band, channels 1-11 are supported. Channels 1, 6, and 11 do not overlap each other and so give you the best chance at reducing congestion, so try each in succession, although depending on what channels your neighbors are using, other channels in the 1-11 range may work best. Also, reducing router bandwidth from 40 to 20 kHz may also reduce interference.
Note that optimum channel choice can be a moving target as neighbors bring new routers online in your vicinity, or reconfigure their routers to use different channels. I periodically use a wifi analyzer app on my smart phone that can show me which available wifi channels have the least congestion and I change the channel my router uses accordingly. I don't know if that explains my battery longevity (usually 3 months or more with fairly heavy use) but it's probably worth a try to see if it helps.
Please report back to let us know how you make out.
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X
