I went for a ride the other day and the same problem occurred. The Battery shut down at 15 miles with around half of the meter bars still displayed. The voltage was 49.9.
The difference from the last occurrence was that I did not charge my battery when I got home. The next day when I went to check the voltage, the battery did turn on and the voltage was 50 volts.
I think I am dealing with a problem with the thermal protector within the battery. I am calling Juiced tomorrow to discuss this.
Well, the Good News is that you've got decent riding weather in November, the Bad News is you can only ride 14 miles. Yea wings02, it's no fun getting onto your E-bike and wondering how far it's gonna go before the Gremlins have their way. Hopefully Juiced does the right thing and replaces your Battery w/ new if it's a Warranty issue or sells one at a very good discount.
Again, I'm w/ Tars Tarkas on this one, clean ALL the connectors w/ an appropriate cleaner, including the Speed Controller stashed in the frame, and apply some dielectric grease (silicone grease w/ electrical conductive properties). That'll get you a better connection than factory and will give some moisture-proofing qualities to the connectors.
It's occurred to me that your Brake Power Cutoff proximity sensors/switches within each of your Brake Levers may be the source of your problem. There is an additional lead coming off the Speed Controller that serves the same function that should be capped off as it is not used. These switches are operated by proximity to a magnet within the Brake Lever Hyd piston and I believe the circuit is Normally Open on these prox sensors until they get close to the magnet on the Hyd plunger. Here's a couple of Tektro YT videos that explain this system. You don't need all the fancy detection displays or Brake Lever adjustment tools. You can easily do this with an Ohmmeter
Vid One and
Vid Two.
The Logan Brakes are knock-off's of the Tektro HD-E350's and the sensors are interchangeable. You should be able to determine if these Cutoff Sensors within the Brake Lever assy is working in your garage. I'd unplug both sensors, set the bike up so you can allow the rear wheel to turn freely, get the motor going w/ the throttle or Walk function and plug in the sensors. If the motor quits you've found the issue. Also, it could be as simple as a sensor tightened too close to the magnet to begin with and may only need adjustment.
That's my Two Cents worth, Good Luck.