Hurricane battery problem AGAIN?

with the charger plug in, what’s the voltage on the XT60 connector?

are both ur charge port mosfet module still intact?

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Yes but not when the battery is practically empty.

49.5V. Exactly the voltage as on the charger itself.

Think so, everything looks fine.

Well, not sure, what do you mean? Board was fully charged (at least it said so on the remote) when it happened (minus the 1-1.5km), and acceleration was strong (unlike when the board hits below 25%, where it is obv less). I did ride the board until the remote vibrated (indicating low battery) BEFORE that last charge, but even then, the BMS should shut the board down before any damage can happen (before total emptyness, right?).

Or did I understand you wrong?

I have heard that rule of thumb once somewhere years back in this or the other forum and I never had a problem but a friend of mine had bc of ignoring it.
He ruined more than 3 Boards with braking to “early” so thats my mindset.
Maybe you are right, but Im going this route for years without issues.
Im no battery expert so bms things here or there isnt my game, you have to trust battery builders like @Simeon or other proffessionals.
I would still bet its the cause.

This is simply not true.

@ridiculed Where are you located?

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Europe

He’s gonna visit me on Sunday and bring the board over ^^
I’ll take both batteries apart and hopefully build one working battery out of that.

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10% of such a battery is probably 5km, how can you ride for five kms without braking?
And I remember that meepo had over charge protection, but I may be wrong…

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Yes, looking forward to having a go at the Prototipo and eFoiling in Dresden on the same day @Simeon :slight_smile: And meanwhile, Meepo has looked through all the vids and explanations I gave them an decided… well :wink:

Ok then. Tell us the truth.

5 posts were merged into an existing topic: Derail Jail 2022

I am sure that there is a place in the interwebbbs where conversations getting personal are more appreciated, but I have a feeling that this is not the place. Take it easy, this is an exchange of opinions on technical questions, and for no reason it should ever become personal.

Back to the topic: I am considering just having Meepo send me the ESC that they so desperately want to send to me (instead of the new battery, which it seems that most on here agree will be the point of failure). And then, when the thing arrives, inform them that actually the ESC does not solve the problem. Kinda strange for them to not come to the same conclusion after watching all the video material I supplied them with. What would you guys do?

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If you’re cinvinced your battery is tthe problem, maybe you should send it to one of the trusted battery builders in europe, for repair…?
Find some here

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:blush:

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Ok then I’m def out of this thread
Good luck @ridiculed
Sorry for the brief derailment :wink:

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It’s simply not how cells behave in those situations, or how hard braking ends up affecting the voltage of the battery.

To begin with, as soon as you remove the charge, the voltage settles lower than the charge voltage. How low depends on different factors, but rarely is a board literally ‘full’ when you take it off the charger and go use it. Part of the buffer exists there.

Also, the moment you start riding, you’re drawing current. Starting from a stop takes a decently large current draw, followed by more moderate draws of current as the motors are driven to their desired speed and held there. So right away you’re drawing several amps for constant amounts of time.

When you brake on a board, the entire braking event isn’t usually handled by regenerative braking unless you’re lightly riding the top end of the brakes down a long hill.

In the vast majority of braking events, the regenerating gives way to the ESC using more current to drive the motor in the opposite direction for higher strength brakes.

You can see this when you log data. Here’s a screenshot during a test ride. And most braking events look like this, electrically.

You’ll notice that not only does the initial regen not raise the voltage very high at all, but as the speed decreases further, the voltage drops again as current is drawn to clamp down on the tail end of the brake.

I don’t know who told you about waiting longer distances before using your brakes, but you have been misinformed.

As for the case of this Hurricane, an above opinion sounds correct to me.

The first failure is likely related to the cells, and the second is related to the BMS.

If it were me, or really if @ridiculed has access to a tech with this expertise, I’d swap the BMS into the 2nd battery and test that, after I confirmed the ESC to be working normally with a known functioning test battery.

I realize this is probably not feasible, but it seems the ESC is indeed fine, and I imagine the prospect of having 2 junked entire battery assemblies is less than ideal.

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Thank you for this.
Lots of information and detail here I have to work through.
Dont know from where i have this "wrong’ information about draining rhe battery first. For me it worked out well on these kind of chinese boards to ride a few km first before hitting the brakes hard, f0r a friend of mine who hit the brakes after going up a small hill first and then braked not. Many times.
I observed that with vesc you re “just” losing brakes, cheap esc destroyed the batteries ( that was what im thinking lol ) Many vids on youtube when dudes riding their chinese boards for a few km the first time their boards gave up. I always thought it was bc the battery was fully charged and they hit the brakes just to early. So, i always go a few km before using my brakes, but im riding vesc and no cheap esc anymore.
Works out for me without any issues si i stay that route :people_hugging:

Beautiful breakdown, thanks @TheBoardGarage . Much appreciating the spreading of knowledge here, gotta say. Yes, the BMS change will be the way to go with @Simeon , hopefully that will do the job. Obviously, I would still like Meepo to “take responsibility” while on warranty and send me a new battery, regardless of what I will do with the two “broken” ones. Thanks again for commenting and ‘cleaning’ and so on :slight_smile:

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@TheBoardGarage is spot on with his explanation and I’m glad you said it first so I didn’t need to try and explain it. That much is also true even on Chinese boards with the only exception being if you go down a very steep hill very shortly after riding and you are on the brakes the entire time you’re on the hill. Even when I lived on a mountain I never reached the point of that being an issue though because the regeneration is not very energy efficient and as he said using the brakes takes energy too.

As for the issue with the battery, I had something similar happen. First battery died from being used too much and likely died naturally. It could still run while plugged up since the BMS was functioning. I was still under warranty and was sent a replacement battery. That battery then failed prematurely due to a BMS failure which is easily shown if you board won’t turn on when plugged up.

From what I could tell the BMS failure didn’t kill all the cells although two P groups did seem to be damaged. The rest of the cells worked fine though and were able to be used in a different battery until I accidentally killed the BMS on that battery. (It wasn’t marked and ended up not being designed to handle the current I was putting through it)

I’d at least do some basic tests on the cells before using them with a new BMS just to be safe. Testing each group’s voltage should be the bare minimum and then if you are able to test each group under a load to determine the battery’s internal resistance. This page here gives you the steps to do that, and this article better explains why it matters. Personally, I compared the battery groups to each other to see which ones might be bad since I didn’t have the values from before the first BMS failed on me. There are better methods to check cell health but the internal resistance can be checked with very basic equipment

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