SyncUp Battery Life?

I think the sync up tracker's major defects are the battery life and charging cable.  I am relatively sure making the tracker twice a big would extend the battery life to 10+ days.  Why any company would use a proprietary charging port rather than an UCB-C port is beyond comprehension.   I have three of them and I use them as stealth trackers in my cars.  In order to maintain the battery life, I use a rear USB power port to hide the tracker somewhere in the back of the car.  If it were not for the current promotion of $2/month/device I may have not signed up.