The Bafang M155 motor on my 5+ failed about a year ago on me - after 3800 miles - I use it each day to commute a little over 30 miles round trip to work each nice weather day.  It was a hall effect sensor.  I have not been able to find a replacement motor assembly because I believe, like others have written, that the motor is proprietary to Rad even though it is built by Bafang.  The design of this motor assembly is unlike most others, the motor side of the assembly is on the left (brake) side and opposite the chain side.  You can tell because that's the side where the motor cable comes out of the axle.  The importance of this difference is that the motor cover is on the chain side and not the motor side.  To remove the motor you have to remove the planetary ring, which is shrunk fit into the motor housing.  I'm a decent diy mechanic, and a professional lives across the street; we did not have a three jaw puller between us that would work.  So we built a custom puller but could not get the ring to budge.  We believe the only way to get it off is to heat the housing so it expands and then, in conjunction, use the custom puller.  But we worried what the heat would do to the housing and spoke butts.  So I've unlaced the spokes from the motor housing hub and next step is to apply heat to just the hub.  I'm in no rush though because I bought a replacement from Rad for $600.  Even if I can get that planetary ring out I now have to re-lace the spokes into the rim and re-true the wheel.  I would also have to chill, in dry ice, the planetary ring and try to accurately set it in the motor hub - not a trivial task. Or maybe I can just heat the hub up again to expand it. For me this has been a 4 hour job so far, and to re-lace the wheel and true it will be another 6 or so hours.  I do like tinkering, but it's better for me to go to my job and earn the money to pay Rad for a replacement wheel assembly rather than using my precious off time to replace a $3 hall effect sensor.  My big takeaways are:  never buy an e-bike with a proprietary motor and never buy an e-bike with a motor that is not removable through the hub cover - unless you are willing to accept that the motor can't be replaced.

I had to replace the freewheel on my wife's RadCity 5+ because I plopped the whole thing in an ultrasonic to clean it and I wound up flushing out all of the lubricant... my bad... couldn't figure out how to disassemble it to re-grease it... I couldn't get enough oil into it to free up a pawl (I think) that got stuck... anyway... I went with a DnP 34T which is the stock freewheel that came with the bike.  Got it on Amazon.  Worked great this past week on an long trail ride for her.  Was around $35.

I commute 31 miles round trip each day (weather permitting) on my RadCity 5+.  I use the Roswheel 14892 3 in 1 Multifuction Bicycle Expedition Touring Cam Pannier... available from Amazon... https://amzn.to/3LGy5BS  ... it's 37L total.  This allows me to bring my laptop back and forth and business causal clothing to and from work each day.  I am really fortunate to have access to a locker room at work so I can keep shoes, towel, and toiletries at work.  Mondays and Fridays are my "heavy" load days.  These also worked great for a 120 mile round trip trail ride (was supposed to be 170 miles but rain got in the way) that my wife and I did this week.  I was able to carry three days / two nights worth of clothing, foul weather gear, personal care, and trail tools / spare tubes in this Ros pannier.  She rode with a 50L pannier - can't remember what brand hers are.

Another thing that I like about the Ros kit I have is that the flat bag is easily detachable from the pannier saddle and has a carrying strap.

Good luck!

Here's more on the stock Vee Tire Company tires that came with my RadCity5+

Marking on tire was 50/100-584 M/C 37B MOPED
The 50=50mm width
The 100 = aspect ratio % which in this case means that the tire depth is 100% of the tire width = 100% x 50mm = 50mm deep tire
The 584 is the rim diameter.  This is the same as the 650B European standard
M/C = motorcycle (I think... could not verify)
37B = the load and speed rating ... 37 = 282 pounds .... B = up to 31mph
MOPED = moped application (I think... could not verify).

Here's replacement tire options for the RadCity 5+ that I've researched.... my application is that I use my RC5+ as a daily commuter (31miles round trip).

Schwalbe
Marathon E-Plus
Bead: Wired | Colour: Black-Reflex | Compound: Addix E | ETRTO: 50-584 | Inch: 27.5x2.00 | Quality: Performance Line | Seal: Tube | Version: Smart DualGuard  67TPI  1170 grams
Product number: 11159057.01
They go for $65 each.
They have an E-50 rating (suitable for pedal / electric's) up to 50kph (30mph) continuous {E-BIKE 50KPH (E-50) indicates that tire has passed the ECE-R75 E-Bike certification for E-Bikes with speeds up to 50 kilometers (30 miles) per hour.}
I've also used Schwalbe tires on my "pedal only" commuter bike, prior to getting the E-bike, and have been very happy with them.

Would appreciate if anyone has found other options.  I've not been able to find a source for the Vee Tire Company tires that came with the bike, and the 27.5x1.95 Kenda's being sold by Rad Power as replacements don't seem to be in the Kenda system anymore, but a similar Kenda seems to be their Kwick Drumlin K1216E product 214215 27.5x2.00 51-584   65psi 60TPI   SINGLE K-SHIELD PLUS   WIRE 1463?73g.  These have an E-50 rating too and cost around $39.  They are 300g or so heavier than the Schwalbe Marathon E-Plus.  I personally wouldn't mind the extra weight.

You are right... I was wrong... the Tanus "liner" is an add-on and not stock with the RC5+.  There are lots of videos on the Tanus liners... advantages and disadvantages...  I sprung for a pair and I will use in conjunction with "Mr. Tuffy" liner strips so I can keep the tires hard for lower rolling resistance.  I commute with my RC5+ 31miles round trip each day and I just don't want to deal with a flat if I don't have to.  I'll report back when I get a sense of how the Tanus with Tuffy liners perform.

I think it is noteworthy that the tires on the RC5+ are furnished with a tube-puncture preventing material/liner on the inside of the tire that is supposed to protect the inner tube.  An interesting thing is that the manufacturer of the "liner" states that the tire pressure needs to be reduced.  To 55psi from memory.  This is not reflected in any of the Rad Power guides AFAIK.

I attached a burley to my RadCity 5+.  I went with the axle method by removing the Rad axle nut and replacing it with a M12-1.25 hex coupling nut available as part FBAPM60029-1 from www.clipsandfasteners.com, faying up the burley steel hitch (part 960116) to the outboard face of the coupling nut, and attaching/securing the burley steel hitch with a hex flange bolt M12-1.25 (fine thread) x 20mm long available from www.mcmaster.com as their part number 95735A114.  Cart is 35 pounds and dog is 60 pounds.  No issues to report.  Tows like a dream on asphalt, but I keep PAS at 1 and sometimes 2 and speed at 10mph or less.  Haven't tried higher speeds or rough terrain.  Two photo's attached.

First of all... Thank you to the people who posted solutions and their experiences.

Second... people should stop beating themselves up over sticking the key into the charging port.  I can see this happening because every battery pack I've seen in the past has the key on the battery itself, and not on the frame.

The thing that bothers me is that there should be a reset-able fuse rather than having to disassemble the unit.

Love the bike... happy riding to all!

This answer not applicable to the RadCity 5+.  There is no owner-accessible fuse afaik.  I have same problem.  Battery will not charge.  Have two 5+ at home, each with own charger.  Neither charger will "charge" the problematic battery.