Battery won't charge past 91%

[Planemo]

39 minutes ago, Hectop said:

 Would not the charger keep trying to charge it?

No. The charger isn't looking for peak voltage to know when to stop. It's looking at current draw. Because the battery isn't drawing much current, the green light comes on.

[meepmeepmayer]

50 minutes ago, Hectop said:

I actually purchased it directly from InMotion Canada. I will reach out to them again. But to your point, if it is the battery, why does the charger stop and the light goes green even though the battery voltage is not at 100% yet? Would not the charger keep trying to charge it?

I'm no expert and I'm not sure what is wrong with your wheel (battery). This is how I interpret it:

The light goes green because the charger stopped charging.

The charger stopped charging because one battery pack stopped accepting the charge. Since all packs are connected (at the same voltage automatically), that stops charging into all packs (into the entire wheel).

The battery management system in each battery pack stops charging as soon as one battery cell in that pack reaches its maximum voltage (4.2V). Because charging more would overcharge that cell, which is to be avoided.

So: as soon as one cell in the entire wheel is "full", the wheel stops accepting any charge. The weakest link determines when the charger stops.

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Now the theoretical example scenario: one cell somewhere is completely bad. Electrically, it acts no longer as a battery cell (has a voltage), but simply like a piece of conducting wire.

84V batteries are made from 20 cells in series (20 * 4.2V = 84V). Then you have multiple blocks of 20 cells in a pack, and multiple packs in a wheel (e.g. 2 packs with 2x20 cells each in your V10).

One bad cell means you only have 19*4.2V= 79.8V maximum charge. So the charger will stop charging at that.

So: if you can't charge above that voltage, that is a pretty clear indication that you have a bad cell.

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I don't know if you have a bad cell somewhere. Because you can charge notably above those 79.8V, which shouldn't be possible then. But maybe a cell is faulty and you only get 1.7V from it (which would give you your 19*4.2V + 1.7V = 81.5V). Or multiple cells are slightly faulty? I don't really know how to interpret your voltage. Maybe it's just a crazy charger malfunction and the voltmeter reading of the unconnected charger doesn't say anything? Maybe the board has a malfunction somehow that influences charging? Maybe your battery is damaged.

These are the kind of fine details a seller would know best what they mean

Side note: not being able to charge to 100% is also bad because cell balancing (equalizing the fine voltage differences) seems to only happen at full charge. Not balancing regularly by charging to 100% can decrease battery life and ultimately lead to battery damage (dangerous).

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My point is: your V10's symptoms are cause for concern, because a faulty battery pack can be dangerous. So this is a "Need to find out what the problem is and not sleep on it" situation. Sorry for the bad news (again). EUCs are great, but sometimes frustrating stuff like this happens which can be really off-putting. High highs, low lows. Power through it to get back to the good times (and more range on your V10!)

Definitely contact Inmotion support again. Call if necessary until you get a reply (https://inmotioncanada.com/ has phone numbers listed, I assume that's where you bought, I just googled "Inmotion Canada"). Maybe saying your battery might be damaged and you are worried about the dangers of a fire will get you heard Maybe there are other Inmotion representatives that can help you if you get no reply there.

Edited December 11, 2020 by meepmeepmayer

[meepmeepmayer]

1 minute ago, Planemo said:

No. The charger isn't looking for peak voltage to know when to stop. It's looking at current draw. Because the battery isn't drawing much current, the green light comes on.

That's cool, I didn't know it works like this! Makes sense.

[Planemo]

1 minute ago, meepmeepmayer said:

That's cool, I didn't know it works like this! Makes sense.

TBF, you are kinda right in a way No draw = cells full. But yes, it doesn't mean all is well of course, as you rightly say a duff cell may well not draw any current. Our chargers aren't smart enough to know why theres no draw, only that there isn't. And shoves the green light on.

I live for the day we get BMS's on all wheels which will send an alarm when a string of cells is underperforming. Wishful thinking. Thats one good thing the Z10 has going for it, although most reported errors have been the fault of the BMS itself rather than the cells lol

 

[Hectop]

2 hours ago, meepmeepmayer said:

I'm no expert and I'm not sure what is wrong with your wheel (battery). This is how I interpret it:

The light goes green because the charger stopped charging.

The charger stopped charging because one battery pack stopped accepting the charge. Since all packs are connected (at the same voltage automatically), that stops charging into all packs (into the entire wheel).

The battery management system in each battery pack stops charging as soon as one battery cell in that pack reaches its maximum voltage (4.2V). Because charging more would overcharge that cell, which is to be avoided.

So: as soon as one cell in the entire wheel is "full", the wheel stops accepting any charge. The weakest link determines when the charger stops.

-

Now the theoretical example scenario: one cell somewhere is completely bad. Electrically, it acts no longer as a battery cell (has a voltage), but simply like a piece of conducting wire.

84V batteries are made from 20 cells in series (20 * 4.2V = 84V). Then you have multiple blocks of 20 cells in a pack, and multiple packs in a wheel (e.g. 2 packs with 2x20 cells each in your V10).

One bad cell means you only have 19*4.2V= 79.8V maximum charge. So the charger will stop charging at that.

So: if you can't charge above that voltage, that is a pretty clear indication that you have a bad cell.

-

I don't know if you have a bad cell somewhere. Because you can charge notably above those 79.8V, which shouldn't be possible then. But maybe a cell is faulty and you only get 1.7V from it (which would give you your 19*4.2V + 1.7V = 81.5V). Or multiple cells are slightly faulty? I don't really know how to interpret your voltage. Maybe it's just a crazy charger malfunction and the voltmeter reading of the unconnected charger doesn't say anything? Maybe the board has a malfunction somehow that influences charging? Maybe your battery is damaged.

These are the kind of fine details a seller would know best what they mean

Side note: not being able to charge to 100% is also bad because cell balancing (equalizing the fine voltage differences) seems to only happen at full charge. Not balancing regularly by charging to 100% can decrease battery life and ultimately lead to battery damage (dangerous).

-

My point is: your V10's symptoms are cause for concern, because a faulty battery pack can be dangerous. So this is a "Need to find out what the problem is and not sleep on it" situation. Sorry for the bad news (again). EUCs are great, but sometimes frustrating stuff like this happens which can be really off-putting. High highs, low lows. Power through it to get back to the good times (and more range on your V10!)

Definitely contact Inmotion support again. Call if necessary until you get a reply (https://inmotioncanada.com/ has phone numbers listed, I assume that's where you bought, I just googled "Inmotion Canada"). Maybe saying your battery might be damaged and you are worried about the dangers of a fire will get you heard Maybe there are other Inmotion representatives that can help you if you get no reply there.

Thank you for your VERU detailed and on depth response. I really appreciate it, and have learned a fair deal. I will keep trying to reach someone at In motion Canada and see where I can get. I will post my results.... Cheers!

[Chriull]

2 hours ago, Planemo said:

No. The charger isn't looking for peak voltage to know when to stop. It's looking at current draw. Because the battery isn't drawing much current, the green light comes on.

What i got from all the reports here is that the charger _never_ stops! He just turns the led green once the current goes below some threshold. The chargers are very "stupid" constant current sources up to some constant max voltage 

Just the BMS can cut charging once one cell groups voltage reaches some 4.2xV.

So with a balanced battery one should not let the charger plugged in too long after the led became green, as li ion do not like trickle charging at all!

?New KS? and Veteran imo have mosfets between charging input and battery plus charge current monitoring. Maybe inmotion too?

So the mainboard could possibly cut charging too so no trickle charge occurs...

[mrelwood]

18 hours ago, Hectop said:

But to your point, if it is the battery, why does the charger stop and the light goes green even though the battery voltage is not at 100% yet? Would not the charger keep trying to charge it?

The most common issue with the exact issues you have described, is indeed a group of cells that have a voltage level much lower than the rest. In your case the voltage difference is much too large to be fixed by anything other than replacing the whole battery pack. Or just the infected cells, by someone who is experienced in working with large high voltage Li-ion battery packs.

Why/how?

When the highest cell groups get close to 4.2V, their charging speed is slowed down by a parallel resistor so that other groups have time to get up closer to the same voltage. This is called balancing.

If any of the groups reach 4.25-4.28V, the BMS disconnects the charging current completely, because overvoltage in Li-ion cells is dangerous. After this the pack receives zero charging current, and the charger reacts as if it were disconnected. Which it electronically is. This is why your charger LED was green.

After the above processes, if the total pack voltage is still 81.7V, we know for sure that at least one group was at 4.25V when the charging stopped, and that the average of the other 19 groups is about 4.08V. Problem is that the mentioned "average" can consist of all groups being at 4.08V (good), or it can be 18 groups at 4.25V and one at 0.95V (very bad!). The only way to know is to disassemble the battery pack and measure the separate cell groups. This would include tearing up the insulation of the pack.

If none of the groups have gone below 2.5V while riding, one can try to milk the balancing portion of the charge, which is done by riding just a few miles, charging to full, and repeating for several times. Or one could manually charge the bad cell with a separate single Li-ion charger, which would again require extensive knowledge on how to operate with high voltage Li-ion packs.

If any of the groups has gone below 2.5V at any point, they should be considered as unusable and dagerous.

A big problem is that the distributors generally aren't aware of any of the above. Luckily not charging above 81.7V is by itself a clear indicator of an issue which is covered by a warranty.

Edited December 12, 2020 by mrelwood

[meepmeepmayer]

I hope it's a freak charger/board failure instead of the expensive battery, even though that seems unlikely.

[RoboFixIt]

@Lunar were you able to fix this issue with your V10?

[G-Town]

Hello! I recently purchased the Inmotion V8S. It has the issue you all are describing... it will not charge past 89%. Here are my thoughts on the issue:

a). It seems reasonably likely that there is one or more bad (or partially bad) cells and that is the reason for it not being able to charge 100%.

b). I contacted Inmotion through Amazon and they stated that "although the APP shows 89% of the power, it is actually full. Our engineers can help you calibrate. "

They then asked me to contact them at an email outside of Amazon (which I have not done). 

c). If (a) above is true and this is a common problem--as it seems to be from this thread--then it's reasonably likely that their calibration is a hoax. What I mean is they will make what currently shows 89% the new 100%. Nothing will actually change but it will make the user happy to see 100% on the app. If there is a bad cell that will remain. 

So my questions to this forum are two: 

1). Do you think (c) above is a reasonable hypothesis?

2). Do you think I should return my V8S for a new/different one? 

[meepmeepmayer]

edit: Maybe the dealer has a point, see the replies below. Still a lot to do for a new wheel you just bought.

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My original reply:

1 hour ago, G-Town said:

"although the APP shows 89% of the power, it is actually full. Our engineers can help you calibrate. "

That is a big bunch of bullshit! They lie so they don't have to take it back.

1 hour ago, G-Town said:

c). If (a) above is true and this is a common problem--as it seems to be from this thread--then it's reasonably likely that their calibration is a hoax. What I mean is they will make what currently shows 89% the new 100%. Nothing will actually change but it will make the user happy to see 100% on the app. If there is a bad cell that will remain. 

There is no "calibration" for the battery.

If the voltage isn't 84V, the battery isn't charging to full. The end. (Voltage counts. The battery percentage may be displayed wrong, but not the voltage. What is your voltage?)

1 hour ago, G-Town said:

2). Do you think I should return my V8S for a new/different one?

Yes! Return it, and buy from a non-scummy dealer.

Edited June 24, 2022 by meepmeepmayer

[Planemo]

5 minutes ago, meepmeepmayer said:

The battery percentage may be displayed wrong, but not the voltage.

Tbf the Sherman voltage (displayed) can be wrong. as G-Man said, maybe the seller thinks the V8 can be calibrated (like the Sherman) too...?

Never heard it done on a V8 before though...

Either way, the only way to tell is by measuring the voltage straight off the pack, which I think is what you were trying to say

 

[Chriull]

45 minutes ago, G-Town said:

So my questions to this forum are two: 

1). Do you think (c) above is a reasonable hypothesis?

You should measure the output voltage of the charger and the as full as possible charged battery with a voltmeter.

Then you know.

Afair inmotion had issues with on board voltage measurement and did calibrate custumer wheels remotely.

No idea if it's just a hoax to hide the bad battery or just a badly or not calibrated motherboard.

Did it ever charge to 100%?

But however - doing the measurements is the only way to know whats going on...

[G-Town]

20 hours ago, Chriull said:

You should measure the output voltage of the charger and the as full as possible charged battery with a voltmeter.

Then you know.

Right... I could use some tips on how to do this! I have an analog multimeter (this one). But the prongs are too big to fit into the charger plug (the plug that goes into the EUC). And then where would I measure the voltage coming off the battery?  Thanks. 🙏🏽

[chanman]

Holy heck, an analog multimeter, that's old school as hell.

Anyway, you're probably going to need to a little disassembly of the EUC to measure the battery packs, which you can disconnect from the motherboard and probe the connectors for each pack individually. The charger you can also disassemble and probe if you can't effectively probe the external connections, but this requires a little technical know-how to do safely.

Edited June 25, 2022 by chanman

[meepmeepmayer]

Before disassembling anything, I would just contact the seller (as they asked) and see if they can fix it/what they say. They can answer your questions whether this really is some kind of calibration issue.

You can always check the voltage later.

[Chriull]

20 hours ago, G-Town said:

Right... I could use some tips on how to do this! I have an analog multimeter (this one).

This won't work out. At the needed 250 DC range one cannot really distinguish soke volts in the 80V range...

[G-Town]

3 hours ago, Chriull said:

This won't work out. At the needed 250 DC range one cannot really distinguish soke volts in the 80V range...

Right, I had the same thought. I would be trying to discern a pretty small position difference in that needle! 🤪

[G-Town]

On 6/24/2022 at 12:31 PM, G-Town said:

Hello! I recently purchased the Inmotion V8S. It has the issue you all are describing... it will not charge past 89%. Here are my thoughts on the issue:

a). It seems reasonably likely that there is one or more bad (or partially bad) cells and that is the reason for it not being able to charge 100%.

b). I contacted Inmotion through Amazon and they stated that "although the APP shows 89% of the power, it is actually full. Our engineers can help you calibrate. "

They then asked me to contact them at an email outside of Amazon (which I have not done). 

c). If (a) above is true and this is a common problem--as it seems to be from this thread--then it's reasonably likely that their calibration is a hoax. What I mean is they will make what currently shows 89% the new 100%. Nothing will actually change but it will make the user happy to see 100% on the app. If there is a bad cell that will remain. 

So my questions to this forum are two: 

1). Do you think (c) above is a reasonable hypothesis?

2). Do you think I should return my V8S for a new/different one? 

Going back to these original thoughts and questions... (a) and (c) still seem the most likely to me. I'm going to skip trying to measure any voltages and look into returning the unit I received that never charges beyond 89%.

[alcatraz]

If you can return it then that's the best option.

[Skeptikos]

Hm... Like @G-Town, I also just bought a V8S from what appears to be InMotion on Amazon. And at the moment mine only charges to 81V/90%.

I'm a little torn about what to think-- on one hand, it seems wildly unlikely that InMotion are scammers. On the other hand, Amazon is filled with frauds and fakes.

I sent them a message through Amazon. Guess I'll document what I figure out here.

Edit: And yes, I checked the charger. It's not the issue.

Edited July 21, 2022 by Skeptikos

[alcatraz]

20 hours ago, Skeptikos said:

Hm... Like @G-Town, I also just bought a V8S from what appears to be InMotion on Amazon. And at the moment mine only charges to 81V/90%.

I'm a little torn about what to think-- on one hand, it seems wildly unlikely that InMotion are scammers. On the other hand, Amazon is filled with frauds and fakes.

I sent them a message through Amazon. Guess I'll document what I figure out here.

Edit: And yes, I checked the charger. It's not the issue.

That can resolve itself. Just leave it on the charger for a day and check again.

When storing a wheel for a very long time some cells can self discharge faster than others, just like that. That's what balancing is for. 

[Skeptikos]

On 7/21/2022 at 9:31 PM, alcatraz said:

That can resolve itself. Just leave it on the charger for a day and check again.

When storing a wheel for a very long time some cells can self discharge faster than others, just like that. That's what balancing is for. 

That didn't work for me either.

InMotion tried to "calibrate" the wheel via their app, but that also didn't work.

They decided the control board is misreading the voltage, so now they're sending me another control board. That's also what I suspected, since I noticed the battery/voltage numbers were flickering up and down a lot. On my V8, those numbers don't flicker at all.

Anyway, the upside is that the Amazon seller is definitely InMotion, so I didn't fall for some ridiculous Amazon scam (phwew). And I have some tentative reasons to believe the battery is fine (phwew). Though I'm disappointed that InMotion doesn't have a process to detect failures like this.

[G-Town]

Thought I would give an update as to how it played out for me...

I returned the V8s that would not charge past 89% (on the app). Bought a different one, also from Amazon. This second one shows that it will not charge past 94%. So that's an improvement.... BUT it would be nice if a brand new unit would charge to 100%. 

I kind of gave up after the second try. I'm having fun on my V8S and it has plenty of range (I tend to ride about 5-10 miles each ride). 

@Skeptikos Please post an update here after you receive and replace your control board. 

Also, how did you communicate with Inmotion for the support that you got? Thanks.

 

 

 

Edited July 23, 2022 by G-Town
hit enter too soon

[Skeptikos]

1 hour ago, G-Town said:

how did you communicate with Inmotion for the support that you got? Thanks.

I messaged the seller through Amazon. Then they directed me to the InMotion app for the calibration. (In the app you select "Me" at the bottom and then the "Online Service" tab to message their customer support.) After that didn't work, they asked for my email and emailed me from AmazonService@imscv.com. It's a little sketchy because it's against the Amazon rules, but they seem to be operating in good faith.

1 hour ago, G-Town said:

Bought a different one, also from Amazon.

I'm obviously not a fan of Amazon. Usually I'd order from ewheels, and I only used Amazon this time for the Prime Day deal. I'll definitely think twice before trying that again.