Thanks Guys!

Inoxa, can you name a West coast repair shop that I might be able to get a new (used) battery end cap with charge indicator and ribbon cable?

Not that it matters, but I'm in Calgary Canada

SUCCESS!!!

I decided it would be safer to try and jump KEY to GND using a test light while DC meter was measuring the + & - output terminals and bingo, 54V on the output!!!

The 54V stays on when I remove the jumper!

Looks like i will need to try and repair the chopped charge indicator ribbon cable or maybe see if RAD will sell me a new one but I kind of doubt it...

RIGHT TO REPAIR lives on!

At this point I'm just looking to see how I can turn on the Mosfets...

I wonder if I should jump the VCC to KEY terminal on the charge indicator circuit...

Thanks, but I'm trying to avoid my friend having to buy a new $700 battery when this one is fine other than it won't close the contact between B- and P- on the output.

In another post, https://www.radowners.com/index.php?topic=1025.0
Dick B mentioned "The Rad BMS uses a Sino Wealth SH367008 Li-Ion Battery Management chip" and that "With the key switch in the Off position, the semiconductor switches are off. Turning the key switch on wakes up the chip and the discharge switches are turned on presenting voltage to the battery power connector."

On this battery, there are only 2 wires connecting to the bike, + & - Output and there is no external key switch, however there is an unmarked switch in the center of the BMS board that just indicates on\off.
I have tried both positions and still get no output.

However I cannot find that SH367008 chip on this BMS unless it's on the bottom. I found the datasheet for it which says DSG pin should turn on the Mosfet to complete the negative circuit between B- and P-
There is a 48 pin IC near the Mosfets but I can't read any numbers on it.

This BMS board has 4 Power Mosfets which I can't see any numbers on, and I am reading 54V between the output + terminal and the Gate & Source on all 4 mosfets.

I get continuity between P- and all 4 drain pins
I get continuity between B- and all 4 source pins
I measure 54V between + output terminal and all 4 Gate and Source pins
All 4 gate pins go through a 47ohm resistor and disappear to bottom side of board

My friends Semi integrated battery was dead. He tried to charge it but the charger red led was flashing rapidy.
He then gave it to me to see if I could fix it.

I tried to see if it had any voltage at the output terminals and found zero volts.

My friend has another identical bike and I asked him to measure the battery output terminals and he says he gets 50.7 and that his battery has 8 of 10 bars showing on the charge indicator.
This tells me it should have nothing to do with a key as he tested it off the bike.

I got sidetracked by the blown fuse people and tried to check fuse on this BDLGRADH48140369U22P0020 battery and accidently completely cut the charge indicator flex cable

Then I connected my variable power supply, set at 48V and 2A, to the +&- Output terminals and the power supply voltmeter started below 39V but was climbing in voltage. I let that run for a few hours and stopped the charge when current dropped to zero at 48V. I then plugged in the charger and it charged all the way to 54V when the charger LED turned green.
I let it stay connected for another 6 hours to balance.

Then, I removed charger and again measured the large + & - output terminals and there was still no output!

So then I removed the battery assembly from the case and opened up the blue wrap to expose the entire BMS.
I measure from charge port negative to VBAT terminal and get 54V.
Both 30A and 10A fuses are good.
I traced 54V at output + terminal is good but the negative is not there so that's why I have 0V on the output.

On BMS, I see the 13 testpads for the battery charge indicator (of which I cut the ribbon cable) and I see a KEY testpad beside VCC testpad.
I'm wondering if I should try to jump VCC to KEY to enable the negative output terminal?

On the BMS board is a part number DEB-RP-D9020SN0-00-V0.4
I couldn't find any info online for it...

I don't have a microscope to attempt to repair the ribbon cable. Do you guys know where I can get a replacement? or is it even required? Is it required in case battery is perhaps in Sleep mode?

In summary, the battery is fully charged and I just need to turn on the negative output terminal.
I don't have the bike here, only the battery and charger.

PS. I see 3 pins in between the + & - output terminals. What are they for? There is no connection inside the battery to these pins. There is only the + & - red and black wires that connect to the BMS.