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Battery won't charge past 91%


Lunar

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My V11 had a voltage measurement calibration issue as well, as it showed up to 86V after a charge. This  launched the overvoltage warnings and limits, so I reached out to Inmotion. I had confirmed with a (modern) multimeter that the actual voltage is about 83.6V, so perfectly within normal range.

The calibration was done remotely by Inmotion through the app, and it fixed the issue completely. This was in 2020. V8S has been introduced after that, so I'm not surprised that it has the calibration function as well.

It's no scam, no lie, and not a gimmick to "make the owner think" anything. It's a feature that Inmotion has designed into their wheels. And since the wheels should be stored at around 40-60% charge, I don't see how Inmotion could realistically charge each wheel to full, then calibrate each wheel and then discharge to 50% before shipping. Handling a few remote calibrations after the sale simply makes more sense.

I do suggest that everyone who has an odd full charge reading would go through with the calibration, for three reasons:

- It allows you to use the full designed capacity of the battery.

- It enables all voltage based warnings to take place correctly.

- It lets Inmotion know how many and what kind of calibration issues there are. This can help them optimize the manufacturing process for future units.

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I recently bought a V8S on Amazon, and no matter what I do the battery won't charge above 88-89%. It just flickers between the two.

1.) Do I need a new charger? The one they sent me isn't good enough? No idea.

2.) Is it dangerous to keep?

3.) Anyone figured out a way to solve it that doesn't involve buying more stuff!?

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34 minutes ago, sirenspear said:

I recently bought a V8S on Amazon, and no matter what I do the battery won't charge above 88-89%. It just flickers between the two.

1.) Do I need a new charger? The one they sent me isn't good enough? No idea.

You'd have to measure the charger output to determine if the charger is faulty.

34 minutes ago, sirenspear said:

2.) Is it dangerous to keep?

I don't think so.

34 minutes ago, sirenspear said:

3.) Anyone figured out a way to solve it that doesn't involve buying more stuff!?

Contact your seller. Either to return the wheel as a broken one, or for them to hook you up with Inmotion for a remote calibration. Although:

23 minutes ago, sirenspear said:

Checking again - my voltage is bouncing between 80.9, 81.7 and 81.9 over and over.

That might indicate that a bad calibration might not be the root cause since the range is so large. You'd probably have to return the wheel for a new one.

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12 hours ago, sirenspear said:

Checking again - my voltage is bouncing between 80.9, 81.7 and 81.9 over and over.

This sounds similar to mine. You can message them on Amazon and go through the same process I did. If yours is like mine they'll offer to send you a new control board.

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7 hours ago, sirenspear said:

Is there no way to calibrate the battery via; the software to fix it?

The calibration in question is calibrating only the voltage measurement baseline for the mainboard. And there is nothing the user can do about this. Other than to contact Inmotion that is, which I suggest you'd do.

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  • 2 weeks later...

This is not specific to V10 only, but to few other older Inmotion wheels. I do not have a V10, but I deal with a V8F. I also posted in the V8 thread which deals with the same issue, my V8F won't charge over 89-91% (Inmotion app shows 89, while EUC World shows 91). I have it from February 2022, and it was always like that, but never bothered me very much, as I also have other wheels. I mean, it didn't make problems like cuts or other, but it did bother my OCD and my pride a lot, haha. Initially, I bought it in the hope that my wife will learn to ride (she is a small person), but she was not interested, and I ended up riding it myself, and I am still riding it sometimes when I came from work too tired to wrestle with a bigger wheel. It is a very nice wheel to ride. The charger measures right (tested with a multimeter and with an electronic load), moreover it is able to charge other wheels to 100% (yep, I also played with the potentiometers inside, that regulate the voltage and current). The charger is "stupid" (in the sense that it is not what we would call an "intelligent" device, in any way, there is no controller, just a couple of classic power ICs), it is just providing the right stabilized DC voltage, and there is a LED that will turn red if the load (i.e. your unicycle) sucks more than 400mA, or it will turn green otherwise. So, all the "intelligence" is inside of the wheel, the decision of how much current to suck if the voltage of the batteries are this or that (the CC-CV charging algorithm) is done by the firmware inside of the wheel. This firmware sucks. I assume that the charging indication is also a bit misleading. A proof would be the fact that with 89% charged batteries I still can go about 30km with that V8F, which is the same range as famous youtubers with my weight and my riding style can get, with their 100% charged wheels. (I am a heavy guy and push this particular wheel close to the tilt, which in my case is about 30-33km/h). One more reason to believe in a firmware bug, or any issue with the BMS, is the fact that too many people have this issue with V8x and V10x wheels, to think that all of them have one cell broken in their battery pack (as someone suggested to me in the other thread).

My question would be if anybody really solved this issue, and how? Firmware upgrade? Change the BMS/battery pack? I will open this wheel soon (as it is getting closer to 1000km) and will try to charge the battery separate, using a power supply, to see what's going on, and to clarify this dilemma once forever.

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Just got a brand new v8s last week and mine only charges to 93% with voltage showing a steady 81.8V (inmotion app). Kinda just want to keep riding it, hope it's safe. Already had to take it for a repair for clunking noise on the tire so don't want to take it back again. Will keep following this thread

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6 hours ago, LaurV said:

the decision of how much current to suck if the voltage of the batteries are this or that (the CC-CV charging algorithm) is done by the firmware inside of the wheel.

This is incorrect. The wheel does not control the charging current. During the CC phase the charger determines what is the maximum current it is allowed/programmed to give out, and raises the output voltage based on that. That's why there is the Amp rating in the chargers themselves. The wheel doesn't know this rating.

Once the voltage has reached the maximum that the charger is adjusted to, the voltage stays constant as it enters the CV phase. The charging current is then determined by the difference in the charger's maximum voltage and the battery's charge voltage at any given moment. As the voltage difference decreases, the amperage decreases. Still not controlled by the wheel's firmware in any way.

What the firmware does during the charge in some modern wheels is to monitor that the current doesn't get too high (KingSong), or that the separate battery packs have roughly the same voltage level (Inmotion). Shermans also monitor the end of the charge and stops when the current gets below a certain amount.

(Edit: In addition the BMS inside each battery slows down charging of cell groups that are above about 4.18V so that the groups with a lower charge can catch up. But if the difference is too large:)

All wheels have a BMS that stop the charging process completely if any of the individual cell groups gets above 4.25V or so. And this is why your wheel doesn't charge to full, because the BMS stops the charging abruptly.

You can monitor the charging current either from some EUC apps or with an external device. In your case the charging current all of a sudden drops to zero. On healthy wheels the current tapers down slowly and never stops completely.

Edited by mrelwood
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What a wheel's firmware does during charging is highly variable though... at one time there was firmware for my KS 16X that would beep 6 times and shut the wheel down, presumably when the thing was happy with balancing but nobody knew for sure (it could have been the 10 minutes-without-reason-to-stay-powered-up too). Later firmware took that away.

Edited by Tawpie
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1 hour ago, speedofsoul said:

Just got a brand new v8s last week and mine only charges to 93% with voltage showing a steady 81.8V (inmotion app). Kinda just want to keep riding it, hope it's safe. Already had to take it for a repair for clunking noise on the tire so don't want to take it back again. Will keep following this thread

I suggest that you try to cycle the charge level between 80% and 100% at least 4 times: Charge it to as full as it gets, ride calmly only to about 80%, then charge to full again. This can sometimes salvage battery packs that are at the verge of being unbalanced beyond repair.

And about wether the wheel is safe to ride, the answer is "maybe, maybe not". The worst case is that one of the cell groups is down to 2.0V even after you have charged the wheel. As you ride, it drops even lower. Generally battery cells should be discarded if they ever get below 2.5V.

The best case scenario is that the variance between the highest and lowest groups is only 0.2V, in which case the cells are still healthy, but in a dire need of repeated balancing.

Either way, unless you get to balance the cells properly and charge to 99-100%, your battery pack is on it's way out.

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2 hours ago, speedofsoul said:

Just got a brand new v8s last week and mine only charges to 93% with voltage showing a steady 81.8V (inmotion app). Kinda just want to keep riding it, hope it's safe. Already had to take it for a repair for clunking noise on the tire so don't want to take it back again. Will keep following this thread

Contact your seller and ask them about the Inmotion calibration thing. Maybe it's just a wrong voltage reading.

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1 hour ago, meepmeepmayer said:

Contact your seller and ask them about the Inmotion calibration thing. Maybe it's just a wrong voltage reading.

Good thinking. I haven't come across a voltage calibration that was that far off, but it could still be possible.

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  • 1 month later...

Hi All

I would just like to share my experience with everyone that has this battery problem....

I recently bought a V10F and it would only charge to 90% like a lot of other people on this thread . I emailed Inmotoin with the service email address i found in an earlier post . Within 12 hours of sending the email explaining my situation, i had a reply. The end result was their service department connecting remoteley through the Inmotion app and updating what i think to be the software .....while updating it made a few beeps and at the end the battery was showing 100% .......Result :clap3:....

I can't praise Inmotion enough for their super fast response :thumbup: ...So impressed with them ...

So i hope this gives other people with this problem a little help :)

If anyone needs more info about my experience....ask away 

Thanks Jerry

 

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  • 1 month later...
On 9/30/2022 at 11:58 AM, J3rry said:

Hi All

I would just like to share my experience with everyone that has this battery problem....

I recently bought a V10F and it would only charge to 90% like a lot of other people on this thread . I emailed Inmotoin with the service email address i found in an earlier post . Within 12 hours of sending the email explaining my situation, i had a reply. The end result was their service department connecting remoteley through the Inmotion app and updating what i think to be the software .....while updating it made a few beeps and at the end the battery was showing 100% .......Result :clap3:....

I can't praise Inmotion enough for their super fast response :thumbup: ...So impressed with them ...

So i hope this gives other people with this problem a little help :)

If anyone needs more info about my experience....ask away 

Thanks Jerry

 

Can you please tell me email adress?!

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  • 2 months later...

New calibrations have been performed remotely...

Look at the post of LaurV from August 10, 2022 in this topic - I think and my opinion is thatˈs the all problem.

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On 9/30/2022 at 11:58 AM, J3rry said:

Hi All

I would just like to share my experience with everyone that has this battery problem....

I recently bought a V10F and it would only charge to 90% like a lot of other people on this thread . I emailed Inmotoin with the service email address i found in an earlier post . Within 12 hours of sending the email explaining my situation, i had a reply. The end result was their service department connecting remoteley through the Inmotion app and updating what i think to be the software .....while updating it made a few beeps and at the end the battery was showing 100% .......Result :clap3:....

I can't praise Inmotion enough for their super fast response :thumbup: ...So impressed with them ...

So i hope this gives other people with this problem a little help :)

If anyone needs more info about my experience....ask away 

Thanks Jerry

 

Can you tell me the email adress to get in contact with the Inmotion service, please!

 

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On 1/19/2023 at 8:56 AM, AlenP said:

New calibrations have been performed remotely...

Look at the post of LaurV from August 10, 2022 in this topic - I think and my opinion is thatˈs the all problem.

Maybe you are right, but no one tells exactly how to solve it, no one shows the contact email to Inmotion ….. :-(

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13 hours ago, Chriull said:

The email should be service@imscv.com

Maybe also @Inmotion Globalreads this here - also their account has not visited this forum for some time...

ps.: @Cecily Inmotionshould be the active inmotion representative.

Thx!
I already have send an email to service@imscv.com many months ago but did not get any answer 😢

I hope Cecily will help me 🤔

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