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[Mr. Fusion]

Hi


Unfortunately I didn't ride my 2014 DS for a long time. I left it stored in a shelter for over a year.
To make sure the battery wouldn't drain, it was always plugged into AC. At least that's what I thought.

When I wanted to start it for the first time yesterday, it stayed completely off. No reaction on the dashboard, all LEDs of the BMS were off.
It didn't show any reaction to plugging out and back in the charging AC cable.
After checking the voltage, I figured that the AC cable was broken. It must have been damaged at some point. It didn't show any visual damage though...

Now I'm trying to revive my Zero.
Plugging it in with a working AC charging cord didn't help unfortunately.

Any idea what the easiest way is to measure the battery pack voltage?
Can I somehow get access to the battery terminals through the auxiliary charger port? Do I need to provide some voltage to a contactor first?
Any chance that I could revive it by providing some external power to get the battery back to a certain voltage until when the charger would kick in again?

I'm an electrical engineer, so I'm away of the various dangers that come with batteries and the 115V of the Zero battery.
The battery is still under warranty I guess, but without being able to start the bike it would be quite a hassle to get the bike to a dealer.
So it would be nice to do some first aid first


Thanks already in advance.

[Kocho]

Unless the "AC cable was broken" from the factory or otherwise failed during normal operation, I doubt this would be warrantied - you basically left it to discharge too low.

That said, if you are lucky, the battery is not completely flat and could potentially be charged back. I'm not sure exactly how to get access to it directly though. Hopefully someone else will chime in. You have to first assess the health of each cell though - if some are "dead", attempting to charge them might not be advisable!

[hubert]

Since the BMS has shut down everything, there is pobably no other option but to take the 4 battery packs off the bike and do some surgery on each of them. Not even sure the dealer can do that. Only the factory. Or some good electrical engineer. :-)

If you can open the packs to access the cells, bypassing all safety devices, you will be able to measure and maybe try and charge them to at least 3.5V per cell or so, checking all votages being even. Once this is done, maybe the BMS will wake up and everything goes right, or there is an additional need to have some communication with the BMS (and possibly the main bike board) to say "OK I'm the guy from Zero and everything is repaired, you bike can restart normally". Using the CAN bus.

[NEW2elec]

Any chance a fuse blew?  Any LEDs on your BMS window?  Dealer trip will almost surely be needed.
Keep us posted on what you find out.
Seems to be signs that something in these bikes does not like to just sit.

[Mr. Fusion]

Hi guys

Thanks for your input.
I think the next thing I'll do is to check whether I can measure something at the aux charging port.
If not, then I'll probably remove the power tank and check whether it'll give me some more information.

[Mr. Fusion]

I'll also check the fuses.
The BMS leds are all off...

[BrianTRice@gmail.com]

The accessory charging port won't indicate voltage unless the contactor closes.

I can think of two straightforward options:

- Remove the front battery panel and check the connections to the cross connects on the side behind the BMS.
- Remove the cover from the doghouse to check around the contactor.

Your warranty is forfeited in either case.

Take all electrical safety precautions; I don't even know what risks a discharged Zero battery represents. I would presume you'd have to charge it extremely slowly if at all below 88V.

Was the storage kept above freezing for the unattended year?

[Mr. Fusion]

Update:

I checked the fuses and (unfortunately) they're all fine.

Then I removed the Power Tank and opened the part where the BMS is located.
The cell voltages are really low (~0.4V). I'll try to charge then very slowly using an external Li-Ion charger.
For that I ordered one of those:
http://www.digikey.com/products/en?keywords=S7306-ND
I'll use it for creating an adapter to connect my external charger to the Power Tank cells.

[hubert]

Is the 0.4V measured directly on the cell terminals? If yes, they are definitely dead. If no, if it is through a transistor or other switching device, it means the switch is OFF and the voltage would be somewhat meaningless, needing to find direct access to cells terminal.

[Mr. Fusion]

it's measured from the BMS connector to the cells. So probably directly...

Let's see how the cells react to some current...

[wontuan]

it's measured from the BMS connector to the cells. So probably directly...

Let's see how the cells react to some current...

If it is true that your BMS is off and the cells are at 0.4v I would recommend you not try to charge them up. Your cells are considered dead and shouldn't be charged up. Charging over-discharged cells is dangerous and it is recommended that you contact Zero right away with your findings and let them help you replace the battery.

[Kocho]

Yup, if indeed that low voltage, from what I understand myself (which is not much!), the chances of recovery of any useful capacity and function are low to none. And the recharge would be tricky, dangerous if done at too high current. Since you can't monitor each cell's temperature, I think it is unsafe to attempt to recharge them.

Here is an interesting read:

http://www.electricrcaircraftguy.com/2014/10/restoring-over-discharged-LiPos.html

[Skidz]

In my RC days, when those Kokam's were hard to come by and really expensive, I revived LiPo's that were 1v/cell by charging them really slow at about 1/10C. But reviving an entire Zero pack is a totally different story since the cells are tucked away and you can't visually check if they are puffing or heating up... And if a cell in the center of the pack catches fire, you risk a chain reaction with catastrophic consequences. With, if you are very lucky, only a burn spot on the driveway where your battery pack used to sit.
I'd contact Zero about this...