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[raystl]

I am using a 2018 dsr powertrain for my electric plane. Maybe. components were extracted from the bike last fall. Now after reassembly everything is dead regardless of  key position. No contactor noise.

I reset the BMS and got the single green flashing saying battery system ok. Battery input voltage to the DC-DC convertor was a scary low 95V. When I plugged the charger in that voltage dropped to 28V!?

I was able to check high voltage fuses 2 and 3. Shamefully I cannot find fuses 1 or 4.

I am out of straws to grasp. Any ideas?

Thanks.

[BrianTRice@gmail.com]

What charger did you plug in?

Have you checked the MBB and/or BMS logs?

[raystl]

All I have is the charger it came with ( waiting for a Diginow.

Nothing is active so don't know how to get at any logs that might exist.

[BrianTRice@gmail.com]

The BMS has a serial port for diagnostics that you should be able to access:
https://zeromanual.com/wiki/Unofficial_Service_Manual#Battery_Management_System
http://electricmotorcycleforum.com/boards/index.php?topic=7561.0

[flattetyre]

All you need is the controller motor and your own battery source. Zero's batteries are like twice as expensive as cost per kwh to make your own from canned cells. So that would be a option if this falls thru. Whether you can salvage the pack depends on what went wrong and what kind of degraded performance / annoying work you want to accept.

[raystl]

Ah, i see, Brian. Coincidentally i have parts on order from digikey for MBB access. That will take a few days to get here and i still need to track down the molex plug as well. i will pursue that.

The life of the bike was about ten minutes of running from a staring at full charge before it was disassembled. Sigh.

The most likely possibility of misadventure the system suffered is perhaps a broken wire or pin connection.  Don't know if that could cause these symptoms. The voltage drop when the charger was plugged seems particularly weird.

Flattetyre, the plane is designed for a Zero pack to fit. Anything else would be a major change and delay.

BTTW what is the Low Power B+ circuit, mentioned in the manual and and where is its fuse in the harness?

[BrianTRice@gmail.com]

It could be that your battery is fine, and you somehow witnessed the effects of an incomplete precharge cycle.

Try to review the connections carefully and where and how you measured pack voltage to understand what the measurements were tapping.

Given a professionally electrically-safed work environment and toolset (fully insulated to avoid unsafe cross-terminal contacts), you could open the doghouse and measure pack voltage upstream of the contactor.

[raystl]

Yay, hope.
I took all the screws out of the doghouse earlier, but it still would not budge... did not want to force it. Perhaps I should pry it off.

Then I saw that there is unswitched pack voltage delivered to the pins 2 and 3 of the DC/Dc convertor. that was where I measured 95 volts idle and 28V (!!!!) when charger plugged into AC. I will buzz out those feed lines at connectors for the convertor and the pack.

Another symptom... when I reset the BMS, the LEDs indicate ok, blinking every 2 seconds. Some time later (10 min, 1 hr?) the blinking stops and there are no lights. A hardware reset will return the LED ok message. 

[raystl]

Latest attempts at progress...

Checked and verified all lines to connectors for B- unswitched B+, switched B+, keyswitch from MBB to BMS.

Per unofficial manual I cycled the key several times to goose the precharge. No effect. Would like to try fuse 1 check for dead system as discussed in http://electricmotorcycleforum.com/boards/index.php?topic=7963.msg68355#msg68355
But still cannot find fuse in my harness or on 2016 FX dwg.

By measuring B+ and B- and controller and aux chart port,conformed contactor never comes on.

By measuring input voltage at convertor connector, with no charger get 94 V. Plug charger on and voltage drops to 27 V. Unplug charger and voltaged drifts back to 94V. This is baffling since there should be no connection to the always on 12V circuit! Is a problem in the CAN circuits between charger, MBB and BMS having this side effect? I will check the CAN lines tomorrow.

Perhaps there are two problems. Is voltage too low for contactor to open. Is there a workaround>
Is there  a way to operate/check the charger by itself without the CAN interface?

[BrianTRice@gmail.com]

I have a concern about why the battery is now at or below 0% SoC, after storage of less than a year.

Most batteries left alone lose less than 1% per month. It's possible that the way the system was disassembled or left dormant that there is a slow discharge circuit somehow. The BMS and MBB shouldn't draw much at all but those boards and the circuits they power while off are all candidates.

Given the current situation and this trend, it would seem relatively urgent to resolve the SoC by inducing a slow/trickle charge somehow.

I would say that it's hard to know why the contactor does not shut without looking at either the MBB or BMS event logs, whether via the serial pins on the MBB plug or by the BMS serial terminal.

[raystl]

Agreed. It seems I need to try to rescue the battery itself before worrying about the rest if the system.

Any ideas how to do the slow charge? Can I put a small charge rate directly through the unswitched power point? Or do I break open the box and bypass the contactor, and presumably precharge circuitry somehow?

The battery has been totally isolated all this time so the MBB cannot be involved.

Thanks.

[BrianTRice@gmail.com]

I don't know how to advise you safely beyond this point. You should get in contact with a professional.

Opening the doghouse shouldn't involve physical force, though. Unfortunately I don't have that procedure written out in detail.

[raystl]

Understood. Thanks for your guidance.

[Auriga]

Pack voltage can be measured on pin 7 and pin 18 on the cable running to the  MBB's 34 pin connector. You'll want to take off the orange cover, then the pins are arranged from 1-17 on the top row looking face on and 18-34 on the bottom. With the charger disconnected, that should give you pack voltage

[raystl]

Resolved.

Fuse 1 was missing. Discovered it was not in the harness but on the side of the doghouse. There was an empty hole. Right after I ordered replacement fuses and caps I remembered to check the parts bag that held bits that were removed when the powertrain was disassembled. There was the fuse and its cap.

Installed the fuse and fired it up. Dash came on and I could power uo the motor and get regen. Charger worked ok too.

Measured voltage at controller was 114.6V. So voltage reading at convertor with fuse out was bogus.

Another case where  the best solution is where I end up looking like an idiot. Fair price for success.

Thanks all.