Begode 134v Models (and possibly T4?) - Latest V4/C4 Charge Board drains battery packs for unknown reason

[supercurio]

4 hours ago, Rawnei said:

I'm just surprised more people aren't vocal about this, maybe if more people complained they would listen. 🫤

You're the first one to really identify the issue, a larger public always needs some time to catch up.

3 hours ago, Paradox said:

Do you think that all new wheels with this board installed are discharging in their boxes as they wait to be sold?  Could be catastrophic for wheels that go unsold for weeks or months.

Unless Begode programmed something to make sure this behavior is disabled below a certain voltage, it will end up like the Hero, for which most of the units arrived with dead batteries to the dealers as the BMS or something else drained quickly.
Dealers had to "revive" each packs manually on which the cells were drained below the desired levels.

[Omidel]

 

 

[Rawnei]

1 hour ago, Omidel said:

 

 

I don't think it's related, he had one pack having vastly different voltage, also his packs was shipped independently of his wheel, so it's just a bad pack.

[mrelwood]

1 hour ago, Omidel said:

“I love the shock! I’m going to replace it to get a cushier ride.”

Bias much?

I get the issue with what to do with failed battery packs. But it absolutely shouldn’t be the job of the customer to fix or replace the pack in the first place. First you need to understand that the new pack isn’t plug-n-play, then have systems in place to charge and measure a single pack. Those are definitely not things that one should expect from the customer to have. Unfortunately, Begode doesn’t tell you any of this. They just ship a new pack.

 That Begode battery BMS failure whine has become all too common lately. But like @Rawnei said, it isn’t related to the leaky charge board. I’m not sure, but it has seemed to me that the voltage drops slower as the voltage gets lower. So it seems that it wouldn’t discharge beyond a certain point. Still, an awfully crappy way to design a pack balancing system. Or it’s a failed board, since we haven’t yet heard from many others having the same issue.

Edited March 5, 2023 by mrelwood

[Wheel Guy]

18 hours ago, Cerbera said:

Are you considering going back to the old charge board ? I am, a bit... hard to make an informed decision when there is no information to be had !

17 hours ago, Rawnei said:

Well something is supposed to be wrong with those and affect balance negatively, pick your poison.

I would rather have a board that discharges than one that may cause a fire.  I had the fire revision before. But it sucks that we can't get answers from begode. And I guess we can't know for sure that these new boards are even safer than the old ones either. 
 

17 hours ago, Paradox said:

Do you think that all new wheels with this board installed are discharging in their boxes as they wait to be sold?  Could be catastrophic for wheels that go unsold for weeks or months.

That is a scary thought... Imagine getting a new wheel that has been sitting at 0 for a long time, even if it still charges and works you've done permanent damage to the batteries. 


I might hold off riding my wheel for a bit longer just to see if there is a cutoff where it seems to stop draining the battery, for science. 

[Cerbera]

16 minutes ago, mrelwood said:

Or it’s a failed board, since we haven’t yet heard from many others having the same issue.

TBH it's not the sort of thing other users will notice quickly unless they have seen this thread. I was unaware of it until I read this, and I bet the vast majority of people who have those charge boards are unaware too. I think we are up to 4 users now who confirm the problem (including me) which is enough to convince me that it is not a single failed board, but its probably the case with all of this revision/ batch. What remains unclear is where the damn voltage is going, when it stops, and if this is intentional or overly worrisome behaviour - ALL of which Begode should have addressed by now.

Edited March 5, 2023 by Cerbera

[Rawnei]

1 hour ago, mrelwood said:

Or it’s a failed board, since we haven’t yet heard from many others having the same issue.

Multiple people here, multiple comments on my Facebook posts and as well as in Telegram discussions, I think we can say for sure it's the board in general:

https://www.facebook.com/groups/ElectricUnicycle/permalink/5926572487440665/

https://www.facebook.com/groups/451073013606363/permalink/579593947420935/

https://www.facebook.com/groups/1320036495138134/permalink/1593425594465888/

Also take into account Kebyes cryptic reply, it seems they are aware of this but can't give a great answer.

This is the board that comes with all new Begode wheels now so maybe more people will notice eventually.

Edited March 5, 2023 by Rawnei

[mrelwood]

4 minutes ago, Rawnei said:

Multiple people here, multiple comments on my Facebook posts and as well as in Telegram discussions

In that case it definitely sounds like a clear situation of a faulty design.

5 minutes ago, Rawnei said:

Also take into account Kebyes cryptic reply, it seems they are aware of this but can't give a great answer.

It sounded a bit as if it were an intended feature in their eyes. I just hope that this issue fuels up enough noise for them to fix the design for the next revision. It’ll still leave a lot of inflicted wheels around though.

[Cerbera]

Just now, mrelwood said:

It’ll still leave a lot of inflicted wheels around though.

Someone has GOT to do that test where they just leave it unridden and see how far down it goes. If, by design, luck or some miracle it stops at storage voltage, then it is a bizarre but ultimately harmless, or perhaps even useful thing in some circumstances - it would be impossible to leave it at full charge for a battery-breaking length of time for example. But surely solving the 'storage charge problem' should not come at the expense of having constantly bleeding voltage...

[Rawnei]

2 minutes ago, mrelwood said:

In that case it definitely sounds like a clear situation of a faulty design.

It sounded a bit as if it were an intended feature in their eyes. I just hope that this issue fuels up enough noise for them to fix the design for the next revision. It’ll still leave a lot of inflicted wheels around though.

I'm guessing a lot of people have older version installed also which is vaguely said to cause balancing issue over time. 🙁

 

The situation with all these board versions and problems is a giant mess.

[supercurio]

2 minutes ago, mrelwood said:

It sounded a bit as if it were an intended feature in their eyes. I just hope that this issue fuels up enough noise for them to fix the design for the next revision. It’ll still leave a lot of inflicted wheels around though.

That's how I read it too. Well meaning to address the balancing issue, but failed implementation with side effects.

I say failed because the whole thing started when @Rawnei and I had to re-balance his packs manually - which brought extra scrutiny on these voltages.

[Rawnei]

Just now, supercurio said:

That's how I read it too. Well meaning to address the balancing issue, but failed implementation with side effects.

I say failed because the whole thing started when @Rawnei and I had to re-balance his packs manually - which brought extra scrutiny on these voltages.

To be fair though that was not long after switching from old board that is said to cause imbalance so could potentially been caused by the old board, but I will measure individuall pack voltages again soon enough and see.

[supercurio]

Just now, Rawnei said:

To be fair though that was not long after switching from old board that is said to cause imbalance so could potentially been caused by the old board, but I will measure individuall pack voltages again soon enough and see.

Good point.
We could try to bring down a couple of them to see if the initial functionality even works, for a better report 😆

Because it seems that all packs get drained instead of the one(s) that would be higher.

[Wheel Guy]

I checked my wheel again now after another 4 days of not charging. It was down 0.7v in those 4 days, compared to down 2.6v in the first 4 days after charging.

I rode the wheel down to 116.5v (40-45%) today and I'm gonna let the wheel sit for a few days to see if it drains even slower at this lower battery level.

[Cerbera]

57 minutes ago, loofv said:

I checked my wheel again now after another 4 days of not charging. It was down 0.7v in those 4 days, compared to down 2.6v in the first 4 days after charging.

I rode the wheel down to 116.5v (40-45%) today and I'm gonna let the wheel sit for a few days to see if it drains even slower at this lower battery level.

Thank you, that will no doubt prove very informative ! I feel suitably guilty for not doing it myself, but I am told it's all going to go cold and snowy soon, so gotta pack the rides in while I can I'm afraid !

[Wheel Guy]

4 hours ago, Cerbera said:

Thank you, that will no doubt prove very informative ! I feel suitably guilty for not doing it myself, but I am told it's all going to go cold and snowy soon, so gotta pack the rides in while I can I'm afraid !

No worries, get those rides in m8! It's gonna snow here too, I will just leave the wheel inside without charging it

[Chriull]

In case someone wonders - latest posts split off to 

 

[digithom]

Hi all, 
I have recently bough a Master and run in to the issue of display and headlights not running at low temperature (and some more other things  but not relevant to this post) and the seller sent me the usual three boards needed to solve this problem.
Then I encountered this thread and since I manage electronics and microprocessor software I wish to give a contribute to this post.
My Master has been provided with charge board V3, and for spare I received the V4 (the one with the connector not welded on the board but at the end of three wires), I ran the charge test yesterday, it charged up to 134.1V,  to get this data I powered on the wheel without disconnect the charge cord, then I unplugged the charge connector and let it for all the night.
This morning I powered on the wheel and eucworld reports 133.9V, we are about 12 hour after disconnection.
In the next days I'll replace the board with the new model and I'll repeat the test and I'll let you know.

Anyway, we have to keep in mind some tech things about batteries and microprocessors

1) every battery shows a drop voltage after charge is disconnected, it is physiologically of the chemistry of batteries
2) keep in mind that power button is a software item, so, some electronics needs to stay always powered in order to listen the button press, this can't cost 0 energy
3) we don't know the logic behind the charge/balance etc ... implemented by Begode so I't is very dangerous to sentence "it is not working properly" because we don't know what should be the properly way, just for example, my old ks18xl, was dropping 10% of battery on the first 1 day, and then it stays at his 90%, even if the charger is plugged and yes, it is normal, every ks18 acts in this way

[Rawnei]

1 hour ago, digithom said:

Hi all, 
I have recently bough a Master and run in to the issue of display and headlights not running at low temperature (and some more other things  but not relevant to this post) and the seller sent me the usual three boards needed to solve this problem.
Then I encountered this thread and since I manage electronics and microprocessor software I wish to give a contribute to this post.
My Master has been provided with charge board V3, and for spare I received the V4 (the one with the connector not welded on the board but at the end of three wires), I ran the charge test yesterday, it charged up to 134.1V,  to get this data I powered on the wheel without disconnect the charge cord, then I unplugged the charge connector and let it for all the night.
This morning I powered on the wheel and eucworld reports 133.9V, we are about 12 hour after disconnection.
In the next days I'll replace the board with the new model and I'll repeat the test and I'll let you know.

Anyway, we have to keep in mind some tech things about batteries and microprocessors

1) every battery shows a drop voltage after charge is disconnected, it is physiologically of the chemistry of batteries
2) keep in mind that power button is a software item, so, some electronics needs to stay always powered in order to listen the button press, this can't cost 0 energy
3) we don't know the logic behind the charge/balance etc ... implemented by Begode so I't is very dangerous to sentence "it is not working properly" because we don't know what should be the properly way, just for example, my old ks18xl, was dropping 10% of battery on the first 1 day, and then it stays at his 90%, even if the charger is plugged and yes, it is normal, every ks18 acts in this way

Hello,

Thanks for posting, couple of highlights in this thread you might have missed:

• The packs themselves does not discharge when disconnected from charge-board so the discharge can not be explained by cell chemistry.
• The discharge happens even when charge-board is disconnected from main-board so it can not be explained by some function on main-board drawing power.
• Earlier version of charge board (Personal experience V2/C2 charge board) does not have same behaviour and does not discharge packs.
• Discharge happens even on perfectly balanced packs so it does not make sense that it would happen as it balances the packs.

It's not dangerous to make observations and assumptions based on those observations, on the contrary it's something I consider to be healthy, my own assumption from my observations is that either something is not working as intended on the design of this version of the board or it is working as intended and it's just bad design overall.

[Rawnei]

So I've been leaving my wheel untouched from fully charged (134.4v) for over a week now, it seems that towards 131v the draining slows down considerably (but doesn't stop completely), yesterday it was at 131.2v today it was at 131.1v, I'm about to do some maintenance on my wheel so I'm taking it apart today, I measured all packs and all 4 packs are at 65.3v so at least it is keeping them balanced, someone observant might say that hey 65.3v * 2 = is 130.6v not 131.1v! That's because I checked the total value reported over Bluetooth and the packs individually with a multi-meter. 🙂

[Cerbera]

1 hour ago, Rawnei said:

So I've been leaving my wheel untouched from fully charged (134.4v) for over a week now, it seems that towards 131v the draining slows down considerably (but doesn't stop completely), yesterday it was at 131.2v today it was at 131.1v,

That is consistent with my results also - my drain over 4 days also slowed considerably as we headed for the 131's.

If that behaviour is consistent, and does fall off there then I am not too worried, and actually quite pleased that this wheel cannot be stored at the very max voltage for any great length of time, which I hope may lead to a less febrile potential fire situation (?). It also gives me some extra confidence that my long down-sloping drive at the start of every ride won't regen it into over-voltage, though it never has done that AFAIK, even when charged to full.

Ok, so are we ready for this charge board issue to be 'logged' in our collective thoughts as one of the more 'non-concerning' issues with the Master ?

[Rawnei]

4 hours ago, Cerbera said:

That is consistent with my results also - my drain over 4 days also slowed considerably as we headed for the 131's.

If that behaviour is consistent, and does fall off there then I am not too worried, and actually quite pleased that this wheel cannot be stored at the very max voltage for any great length of time, which I hope may lead to a less febrile potential fire situation (?). It also gives me some extra confidence that my long down-sloping drive at the start of every ride won't regen it into over-voltage, though it never has done that AFAIK, even when charged to full.

Ok, so are we ready for this charge board issue to be 'logged' in our collective thoughts as one of the more 'non-concerning' issues with the Master ?

First of all we don't know if it stops draining completely, would require us leaving it a lot longer to find out, the only thing we know for certain right now is that it slows down considerately.

Second my personal opinion is that 3.4v loss is quite a bit of capacity loss, a bit too much for my taste.

But with those two things said I will leave judgement whether there is a flaw on this board or not to people more versed in electrical engineering than me, I really doubt we will we will know for sure unless more people complain about this and they release another revision of the board that changes the behaviour if they do then we will know for certain it was not intended.

[supercurio]

6 hours ago, Rawnei said:

First of all we don't know if it stops draining completely, would require us leaving it a lot longer to find out, the only thing we know for certain right now is that it slows down considerately.

Second my personal opinion is that 3.4v loss is quite a bit of capacity loss, a bit too much for my taste.

If we start from 134.4V (4.2V) down to 131V (4.093V), we are still looking about the top of the voltage curve which is pretty steep.

Therefore I would speculate that the drain is constant - only that the voltage drop varies according to the graph above.
It also means that the drain is pretty small, no doubt about it - although still significant.

[Wheel Guy]

On 3/10/2023 at 11:13 PM, supercurio said:

If we start from 134.4V (4.2V) down to 131V (4.093V), we are still looking about the top of the voltage curve which is pretty steep.

Therefore I would speculate that the drain is constant - only that the voltage drop varies according to the graph above.
It also means that the drain is pretty small, no doubt about it - although still significant.

I have done some more testing now. I discharged my wheel down to 116.5v and left it to sit. 24 hours later it actually had 118.2v (48%),  so I'm guessing I had some voltage sag. 
6 days later, it started at 118.2v and dropped to 118.1v instantly. So down basically nothing after 6 days. 
It appears it has basically completely halted the discharge. I take this as a very good sign. Obviously it's still annoying that it discharges a lot in the top end of the percentages, but at least long term storage appears to be safe. 

[Cerbera]

Ok, well that seems encouraging. It's almost like they bleed off to something around storage voltage (108v) then, presuming optimum storage voltage is 3.4v per cell ? 

Which leaves the question 'Is there less risk of fire when off and stationary because the batteries do not stay at their maximum charge' as Begode seem to suggest or is the fire risk they want to be mitigating down to something else about the design of previous iterations ?

Edited March 12, 2023 by Cerbera