ezee torq fault, starts up, odd gauge display, then dies

[brettule]

Hello pedelec hive mind, I'm hoping you can help me troubleshoot an old Ezee Torq bike I've got. I rode home last week and the bike was fine. Put it on charge. Next time I went to take it out the following occurs:

• Turn on the bike. Red LED comes on and stays solid.
• Battery meter does it's LED dance as usual showing the initialisation process.
• After 5 seconds the meter shows this odd LED combo.
• Press the arrows a few times, the blue LEDs don't respond, however if you twist the throttle or pedal the bike the motor will kick in and the blue LEDs show up suddenly.
• Then after about 5 seconds the motor cuts out the the LEDs return to this display. Rinse and repeat.

What I've tried:

• Fully charged battery. Multimeter shows it on 41v.
• The red LED on the PCB where the key is stays on solid red the whole time, even when the motor cuts out at the battery gauge goes weird.
• Checked the fuse connectors inside the battery and they are solid.
• Checked, cleaned and reconnected several other connectors through the wiring.
• Tried the old wiggle various wires while powered up to see if it was a loose connection anywhere but nothing made a difference.

Any ideas on what the fault might be?

 

[Nealh]

It appears the issue is battery related, how old is the battery ?
41v would indicate that it is out of balance and a cell group is low or very weak, a low cell group will crash in voltage causing lvc to come in very early.
41v suggests nine of the cell groups are at 4.15 - 4.2v and one is very low at 3.1 - 3.3v.

The only way of knowing is for the battery to be opened and each cell group tested for a voltage reading to confirm if this is the problem. As you have a multimeter we can show/guide you in to checking the cells if you are able to open the batteries casing to get at the electronics/cells.

P.s
By the way welcome to the forum, just noticed it is your first post.
And a good first post to start with.

 

[brettule]

Hi, and thanks. The bike must be at least 3 years old. My friend would commute on it daily until it started having constant issues with wiring and contacts arcing and melting. He gave it to me then. The pads on the discs are completely worn out which suggests to me its done many miles.

Inside the battery case the cells are all in a blue shrink wrapped plastic. How do I get into it without giving myself a belt? I'm happy to test and get to the bottom of it. Then you lot can tell me if the bike is a throw away or worth an upgrade.

Cheers

 

[Nealh]

As long as you don't short any battery cells or wiring together all is safe to work on.
You will have to show us a couple pics of the wrapped battery, most likely you will have to carefully cut the shrink wrap if the BMS/pcp board isn't on the outside.
Once the BMS board is exposed it's a simple case of disconnecting the 10 or 11 wire multi connector and probing the battery side of the connector to get 10 separate voltage readings.
Show some pics and then we can go on from there.

I'm out for the day now so won't be back on till pm.

 

[brettule]

I'm out for the day now so won't be back on till pm.

Ha. Your in Sussex, England? I'm in Melbourne, Aus. You won't be hearing from me until tomorrow and even then Ive got a country to cheer for in the World Cup and some pints to accompany that.

 

[Nealh]

It appears you threw us, should have opened up with the stereotypical g'day to get the accent drift .

 

[brettule]

41.3v is what it's testing at to be exact.

Ok, I've cracked her open, and peeled away a little of the plastic cover. What's next?

Also, when you say "As long as you don't short any battery cells or wiring together all is safe to work on.", do you mean that if I get a belt from 41.3v off this thing it's not a problem? I've been very careful not to touch any live wires so far after seeing the damage it can do arcing.

 

[Benjahmin]

You won't get a belt from the battery as there' no circuit through you to earth back to the battery. It operates as an isolated supply. However accidently put your knife through two cables at once and you could end up with a vapourised blade and a red face - at least!
The small multicoloured wires below the main output red and black, are the balance wires. You need to get to the bms that they are connected to in order to measure individual voltages.

 

[Nealh]

Your cells are pouch type cells so there should be ten, 41.3v isn't to bad. To get measurements you need to the find the BMS that those small coloured sense wires go to via a connector to a BMS board, 10 of the sense wires are each connected separately to v+ of each cell to monitor voltage. Disconnect the connector and using your meter get 10 voltage readings from the end connected to the wires, one of the wires is a gnd and the other 10 are v+.
Starting from any end of the block probe the first two pins/contacts on the connector, then carefully move the probes along the connector one contact at a time moving the probes along as a pair. Write down the 10 separate voltage readings and post them up here, if the battery is balanced you should see 4.13v or close for each reading. A bad/low reading on any cell will indicate a bad/poor cell.
Another option is to get an accumulative voltage reading by leaving the black probe on the gnd/- pin and move the red probe along each v+ pin to get an accumulative reading ( less chance of shorting probes) reading should go up each time 4.13, 8.26 & 12.39 etc, etc, until you get 10 readings up to 41.3v.
Just be careful and don't allow probes to touch each other when testing or any other contact.

 

[brettule]

Ok, she's opened up. I don't think that connector comes off the circuit board? Should I try get the probe in the top of the connector? Which is the earth? Any advice welcome for my noobness.

 

[Nealh]

Now we can see better there are only ten sense wires so all are v+, you can probe the rear of the wire.
Use the battery gnd for black probe and move your red probe along each wire and write down the voltage reading, reading will go up incrementally.
Post results when done.

 

[brettule]

Which is the battery ground? The cluster of wires on the side all merge into one black wire that attaches to one side of the fuse, the lower black wire attaches to the other side of the fuse. Is this earth?

This is the back of the fuse, the original spade connector melted and the wire wasn't long enough. I've added this blue insulated connector but as you can see it can tend to fall off.

 

[Nealh]

The black cluster will all feed off the battery ground/neg.
No earth as the voltage is DC, only + & - used.

 

[brettule]

The black cluster will all feed off the battery ground/neg.
No earth as the voltage is DC, only + & - used.

Ahh, this is why its safe for me to touch the live wires then huh?

 

[Nealh]

All is ok as long as + & - aren't shorted, then it gets exciting .

 

[brettule]

Here are the results:

Brown    4.0v
Red    8.1v
Orange    6.3v
Yellow    16.4v
Green    19.9v
Blue    24.6v
Purple    28.8v
Grey    33.9v
White    37.1v
Red    41.3v

Looks like orange is knackered then yeah?

 

[Nealh]

Double check them again and ensure you have a good battery in your meter as there are a 5 cell reading anomalies or bad cells.
B 4v good.
R 4.1v good.
Or -1.8v ? very bad though it should read 8.1v as
can't see how a cell can be --, if it is kaput it
should read 0v.
Y 4.1v/4.2v good.
G 3.5v poor or out of balance
B 4.7v very bad over charged.
P 4.2v good.
G 5.1v very bad over charged.
W 3.2v poor or out of balance.
R 4,2v good.

Try placing both probes solely on the connectors for individual cell readings, though you will only get 9 readings it won't matter as we know B is 4v and fine.
Doesn't matter which probe you use first place as follows ;
Gnd & B we know is 4v.
B & R.
R & Or.
Or & Y.
Y & G.
G & B.
B & P.
P & G.
G & W.
W & R.

 

[Nealh]

I would leave this battery some where safe for now in case it catches fire as two cell groups are way over charged.

 

[brettule]

Eeek! Really? Ok. Not sure where I can store it actually. Outside sounds wise.

 

[brettule]

Ok, retested. Maybe my multimeter is a bit crap. I can only get readings to two decimal places for the first 4, then I need to switch up the meter to the next level. Clearly I screwed a few readings up the first time. How's this?

Brown        4.11v
Red            8.22v
Orange        12.33v
Yellow        16.44v
Green        20.5 v
Blue        24.6 v
Purple        28.8 v
Grey          32.9 v
White        37.1 v
Red            41.3 v