Author Topic: No power issue with Magic Pie 5 or battery  (Read 1540 times)

Offline Jim Bowes

  • Confirmed
  • New Member
  • *
  • Posts: 2
No power issue with Magic Pie 5 or battery
« on: September 25, 2021, 04:20:46 PM »
Thanks for letting me in the forum.
I have an issue with my Magic Pie5 or the battery. Last year my battery just quit. I could plug it into the charger and it appeared to be fully charged. Plug into motor and no power. It was two years old so I assumed the battery was dead. I bought a new battery. This week the connector to the battery broke. One wire became disconnect. Ordered new connector and recharged battery. But when I attach to motor no power! Again!
Researching this other batteries have a fuse. The Lifepo4 Battery 10Ah does not appear to have one. So I now have 2 batteries that the charger says is full (old battery still full after a year of no use? Doubtful)
Any ideas as to what the issue may be? Last year new battery solved this but this is an expensive solution surely something is going wrong somewhere. Any thoughts?

Offline Bikemad

  • Global Moderator
  • Professor
  • PhD. Magic
  • ******
  • Posts: 5,495
Re: No power issue with Magic Pie 5 or battery
« Reply #1 on: September 25, 2021, 11:38:34 PM »
Hi Jim andto the forum.

Unfortunately, it is difficult to say what is causing your problem without further testing.

I suggest that you start by measuring the battery voltage on the main output wires of the battery to ensure the correct voltage is available.
If the battery's BMS was faulty, this can prevent the battery from delivering sufficient voltage/current to power the controller/motor.

If the battery voltage reading is OK with the battery disconnected, check it again at the battery's output connector when it is connected and turned on to ensure the correct voltage is still available.

Sometimes a faulty BMS will give a good output without any load, but the output will drop completely when any load is applied to it.

Unfortunately, if a controller fails in a short circuit state, this will also cause the BMS to instantly cut all power when it was connected and turned On.

Measuring the resistance across the controller's battery connections while disconnected from the battery should allow you to see if the controller is short circuited.
If it measures less than 1~2 Ohms between the thick Red and Black power cables, this would confirm an internal short circuit has occurred somewhere within the controller itself or its external wiring.

If the controller is not short circuited, but the battery voltage is reading far too low with everything plugged in and turned On, then the fault is likely to be within the battery itself, the battery connectors, battery switch or battery wiring.

Alan
 

Offline Jim Bowes

  • Confirmed
  • New Member
  • *
  • Posts: 2
Re: No power issue with Magic Pie 5 or battery
« Reply #2 on: September 26, 2021, 06:10:19 AM »
Thank Alan,
I will have to find someone who understands what you are saying to me. I am just a guy with a business on a cargo bike. Unfortunately, finding a company or a mechanic that will work on this equipment is proving to be nearly impossible. The company who put the unit together for me using your kit is no longer supporting the equipment. Other shops will only service equipment they sell leaving me in a tricky spot. I just need a reliable system.
I did have a friend measure out put at the batter it was 50. When I plugged in the motor it dropped to 3.
Bigger question for me is why is this happening? The second is would it be better just to buy a new electric cargo bike so I have mechanics who can fix my cargo bike so I can get back to work.
I deeply appreciate the time you took to answer my plea. Thank you.