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[jotjotde]

Unfortunately I have this issue with the OBC of my MY22 Ribelle now.
If I select a charge current above 9 A, the charger effectively stops working and the actual current starts fluctuating quickly like shown in the video.

Does anyone know what the cause of this is or even has a fix for it?

[PWM]

Did charger exhibit fault after it was plugged in and running normal at 3kW?

OR

Did charger exhibit fault when it initiated the lastest charge session?

[jotjotde]

No fault messages at all.

[PWM]

The charger is tripping on overload and restarting...which is a good sign.

Display shows 3.3kW when trip occurs.

Reduce charger current to 5 amps and verify power displayed reads <1.1kW.

Increase charger current to 8 amps and verify power displayed reads < 2.0kW

Measure AC line voltage if power is higher than expected.

Suspect loose power connection on AC side.

Verify bike takes a DC charge before suspecting anything on DC side.

[Specter]

typical behavior on batteries that have not been balanced for a while, especially if it's been a week or so between charges.  one battery is hitting it's upper limit which is pushing the charger down to zero, which makes the voltage fall back down below the stop threshold, so it tries again.

put the thing to an amp  or two and let it charge overnight until it hits 100 percent or terminates charge on it's own.
if you can, after doing that, get into the engineering screen and let me know what the pack ocv is, and the volt spread on the batterys.  it will say something likeeee3.984 volt    3.889 volt or whatever it is,  that spread is the important part.f

batteries that are cool/ cold tend to do this more often, especially if you put her away hot, or charged hot, didn't finish the charge ,put it away hot / warm, now try to resume cold.

Aaron

[szczur333]

in my opinion this is not about balance of cells, bcoz he will get message about ballancing

my bms was fault and I  got 0,5V difference between highest/lowest cell (YES 0,5 not 0,05V) this as during riding or charging DC (with 3kW a it was maybe 0,2V) idle (0,05V)

I got ballancing meesage at DC charger at 50-70% (depend of what current I set) if course at 5A I will not get it and at 10A i got it at 90-95% i think but i not remember exactly

at AC I was able to charge up to 95-100%

[PWM]

in my opinion this is not about balance of cells, bcoz he will get message about ballancing

my bms was fault and I  got 0,5V difference between highest/lowest cell (YES 0,5 not 0,05V) this as during riding or charging DC (with 3kW a it was maybe 0,2V) idle (0,05V)

I got ballancing meesage at DC charger at 50-70% (depend of what current I set) if course at 5A I will not get it and at 10A i got it at 90-95% i think but i not remember exactly

at AC I was able to charge up to 95-100%

The weak sister (the lowest capacity cell having the highest internal resistance) of the bunch shows on the engineering screen as the highest voltage during charge and lowest voltage during discharge out of the entire bunch...same cell.  So the true pack health is dependent on the weakest cell...that's why it's so important to grade cells when a pack is manufactured...grouping cells by internal resistance is key to pack longevity and easily shrugged as a cost worth cutting...

Good to know Cell-Balance @ 0.5V alerts are given...did not know this...when sitting idle, there is keep alive power and this is sourced from the pack, obviously, but what is not understood is where does the power get tapped from...the DC/DC converter (main one) is not active while bike is parked....there's a separate keep alive battery tap that contributes to imbalance when bike sits for prolonged time...anyone know how it is wired?

[Ingineer]

It's most definitely not tapped!  There is a small auxiliary DC-DC converter that produces 9 volts for the keep-alive.   This is always in-circuit even when the bike is otherwise asleep.   You can reduce it's consumption by removing the small in-line glass fuse if you aren't using the bike, say for winter.

[PWM]

It's most definitely not tapped!  There is a small auxiliary DC-DC converter that produces 9 volts for the keep-alive.   This is always in-circuit even when the bike is otherwise asleep.   You can reduce it's consumption by removing the small in-line glass fuse if you aren't using the bike, say for winter.

Cool, wondering then, if pack is not tapped why do cells become unbalanced when subjected to just low keep-alive current?

Sorry to OP for tangent taken...still waiting for update on discovery steps...

[szczur333]

7

The weak sister (the lowest capacity cell having the highest internal resistance) of the bunch shows on the engineering screen as the highest voltage during charge and lowest voltage during discharge out of the entire bunch...same cell.  So the true pack health is dependent on the weakest cell...that's why it's so important to grade cells when a pack is manufactured...grouping cells by internal resistance is key to pack longevity and easily shrugged as a cost worth cutting...

Good to know Cell-Balance @ 0.5V alerts are given...did not know this...when sitting idle, there is keep alive power and this is sourced from the pack, obviously, but what is not understood is where does the power get tapped from...the DC/DC converter (main one) is not active while bike is parked....there's a separate keep alive battery tap that contributes to imbalance when bike sits for prolonged time...anyone know how it is wired?

my pack was perfectly fine - one day during trip - charging stop at 75%, i thought it was something wrong with my payment option or with DC charger itself, i rode to another charger and it stops at 78%

back then I dont know about engineering screen, some ppl advice to me plug to AC on low A (2-4A) and charge it 0-100% and even on 100% plug it in and try to ballancing

I try to use to new reality and at 70% i lower DC amp at charger to NOT GET ballancing message - then I can charge to about 85-90%

but this is not only disadvantage - two times at 20% i got cut off (battery depleted message) i have to turn bike off and on back after few minutes, and have to ride direclty to charger but very calmly

and most important one - safety - at about 4,0v on highest cell i got 3,5-3,6v on lowest - this means throttle power is not full - I try overtake several cars and my calculation was ok - but losing power during it - I still made it - but it was closes to oncoming cars in opposite directions

dealer cant fixit remotely, I have to send bike to energica direclty - they said something about wrong bms readings only - cells are fine

[Specter]

the 12 volt converter takes the full voltage and get 12 off it, it does not tap, which as you said, absolutely would unbalance.

0.5 volt. umm no   you'll see messages at about 0.050 mv difference occasionally and see behaviors, and at right around 0.100 mv get the serious 'you need to immediately balance now nag'  yes, thats right a tenth of a volt can cause a lot of grief.  been dealing with an issue for a bit here on that.  when battery gets this far out of kilter you can see balance mode start activating at 80 percent  charge or in low ranges instead of like 94 95 percent.  it may take full current up to the 90s but starts grumping at you in the 80s

aaron

[PWM]

my pack was perfectly fine - one day during trip - charging stop at 75%, i thought it was something wrong with my payment option or with DC charger itself, i rode to another charger and it stops at 78%

back then I dont know about engineering screen, some ppl advice to me plug to AC on low A (2-4A) and charge it 0-100% and even on 100% plug it in and try to ballancing

I try to use to new reality and at 70% i lower DC amp at charger to NOT GET ballancing message - then I can charge to about 85-90%

Video shows BMS inhibiting DC charge when weak cell hits high-side-limit.

You cannot balance pack in DC charge mode.

two times at 20% i got cut off (battery depleted message) i have to turn bike off and on back after few minutes, and have to ride directly to charger but very calmly

and most important one - safety - at about 4,0v on highest cell i got 3,5-3,6v on lowest - this means throttle power is not full - I try overtake several cars and my calculation was ok - but losing power during it - I still made it - but it was closes to oncoming cars in opposite directions

Dang, low-side-limit hit at 20% SOC is not good...that weak cell is way out of balance.  You will have to AC charge numerous times until the display at end of AC charge shows 100% which indicates balanced pack...degradation relative to new can only be determined by counting coulombs.

[jotjotde]

The charger is tripping on overload and restarting...which is a good sign.

Display shows 3.3kW when trip occurs.

Reduce charger current to 5 amps and verify power displayed reads <1.1kW.

Increase charger current to 8 amps and verify power displayed reads < 2.0kW

Measure AC line voltage if power is higher than expected.

Suspect loose power connection on AC side.

Verify bike takes a DC charge before suspecting anything on DC side.

TBH I don't understand half of what you guys write about balancing and so on. What I can say is, that the bike is balanced regularly and I did this even daily over the last week because I was on holiday and using the bike. DC charging was absolutely no problem.

Answering PWM's post, I noted the data as shown in the table.
The bike was cold at 15 % SOC. I adjusted to 12 A and it charged approx. 7 minutes, then the amps broke down again.
As already said , charging at 9 A is OK. As soon as 10 A or more are selected, the charging breaks down again.
That is reproducible with different charging bricks and on different 230 V sockets - therefore I definitely thinks it's something with the bike.

@PWM   So you suspect a loose connection? Can you please specify?

[PWM]

What I can say is, that the bike is balanced regularly and I did this even daily over the last week because I was on holiday and using the bike. DC charging was absolutely no problem.

The bike was cold at 15 % SOC. I adjusted to 12 A and it charged approx. 7 minutes, then the amps broke down again.
As already said , charging at 9 A is OK. As soon as 10 A or more are selected, the charging breaks down again.
That is reproducible with different charging bricks and on different 230 V sockets - therefore I definitely thinks it's something with the bike.

@PWM   So you suspect a loose connection? Can you please specify?

Yes, symptoms are consistent w/ excessive voltage drop somewhere in the charger or loose connections...both AC and DC connection to charger is suspect...as shown in following schematic from older Eva than yours, but generally speaking SB similar...

https://photos.smugmug.com/photos/i-RDZ4PGt/0/MGdNNJQcvkpQ8PxHxchjvFMkVPpFggpBp7vbJdwTD/O/i-RDZ4PGt.jpg

Step-1 visually inspect charger power connectors for discoloration from heat.  Be careful to disconnect and inspect the connector faces then reconnect.  Doesn't hurt to spray contacts w/ DeoxItD5 or similar contact cleaner...contacts SB clean and not discolored.

Step-2 try charging again to see if fault cleared from the connectors being cycled.

Step-3 inspect for hot-spots on charger unit itself by using infrared scanner or camera...monitor for heat rise when cold at 12A set-point.  Again, loose connection can be a fastener or solder connection...

Step-4 if above is not possible use back of hand to feel for hot spots on charger face / heat sink / wiring / connectors but obviously stay away from circuit contact.  Allow charger to warm up and start faulting then apply freeze-spray liberally around charger, heatsink and wiring to isolate fault, it should briefly recover once faulty area is sprayed.

Be super careful in your troubleshooting effort...if wiring looks fine it's likely the charger unit itself which can be easily repaired or renewed.

[jotjotde]

@PWM   Thx I am super thankful for breaking it down stepwise for non-electricians.

Step 1: No discoloration or indication of anything out of the order (see pics).
I had no contact spray on hand, so I simply re-attached the plugs.

Step 2: Charged at 12 A for more than 20 minutes without a problem. So maybe it was really a contact problem (corrosion of pin surfaces in the connectors?) and it was remedied by unplugging/replugging.
At next opportunity I will try a full charge at high amps. Unfortunately the weather is not allowing riding this weekend, so this has to wait a few days.

I will watch this closely, but still will try to get a new charger to be on the safe side.