CarPlayBox is draining my iPhone Battery

I have seen many complaints regarding CarPlayBox having substantial drainage issues on the iPhone battery. I believe I have found a workable solution (at least it works for me). I am a Lyft driver and need my iPhone to last more than the 3 hours it was lasting while connected to my CarPlayBox. I tried many things like deleting apps from my car play settings and using different power cords. I believe it comes down to this, if you connect your iPhone to the USB port in your car, it is not getting the required voltage it needs to keep the battery charged. I attached my iPhone to a portable power bank and it did provide the necessary voltage required to work with the CarPlayBox. In fact, my iPhone was less that 100% when I plugged it into the portable power bank and within the next 20 minutes my iPhone was at 100% and remained there for the rest of my Lyft shift. Yes, you need to make sure you have your power bank with you and ensure it is charged, but it works great!! Hope this helps everyone out there.