I have never ridden on a tandem, but I have heard that it will exaggerate your relationship. In other words, if your relationship is great, a tandem can make it better. But if you have disagreements, you will have more on a tandem. Good luck and I hope your relationship gets better with the tandem.

If you have more than one electronic device you might want to charge, there may be times that you only have access to one outlet. I carried a 3 into 1 gizmo so that I could plug several things into one outlet. In the attached photo I am charging four AA batteries, one Li Ion battery for my camera and I have a USB charger plugged in for my tablet.

As Li Ion power banks get more powerful and cheaper, more and more people are starting to rely on them for extra power for between outlets.

My android phone uses very little power in airplane mode and screen off when I am using GPS to record a track. I shut the phone off first to shut off all apps that might be running in the background and start it up and only use the GPS app I want to use at the time.

Paper maps that are large enough so that you can see several days or several weeks of travel are needed for planning your route. And if there are detours, planning your alternate routes. I preferred to look at paper maps when thinking where I might want to stop 3 or 4 or 5 days in advance. Thus, I looked at the paper maps almost every day.

A GPS can be very useful when trying to figure out where to go in small areas where the maps you have lack detail. If you are using a phone, an app that allows downloading maps for off line use later is best. And you should play with the app enough before the trip so you do not have to learn how to use it after you already got lost. There have been several times that I am stopped and looking at a GPS to figure out exactly where to go while standing at an intersection, the paper map did not have the detail I needed.