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Can Someone Provide Detailed Steps to Measure Charger Voltage


Zutto

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rough napkin calculation assuming the marketing glossies are quoting sort of kind of not entirely 'target' numbers... those batts should give you EX20S capacity at the same weight as S22/Master.

I love tech advances! When I was much younger, the first not-desktop PCs were what I dubbed "transportable", not portable. I'm pretty sure a $20 P8 smartwatch from Ali can run circles around a Kaypro. What will wheels be like in 2050?

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3 minutes ago, Funky said:

It will be all about them flying jetpacks.

and y'all will still be grumping about crappy range and cutouts. but suspension bottoming out will be solved!

 

Edited by Tawpie
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2 minutes ago, Tawpie said:

and y'all will still be grumping about crappy range and cutouts.

At least we will have parachutes, that will save our asses. On wheels - hello ground. And good night. :D 

Also no road rash. :D 

Edited by Funky
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1 minute ago, Funky said:

parachutes

Doubtful they will prevent injuries for many cases at such low altitudes. My bet is that many will reminisce about how much safer euc's were back in the days. 🙂

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1 hour ago, techyiam said:

Doubtful they will prevent injuries for many cases at such low altitudes. My bet is that many will reminisce about how much safer euc's were back in the days. 🙂

We are talking about 2050 years. I bet we will "fly" much higher.. Mini helicopters heights. Heights where people still have time to deploy. :D

If anything else - you won't fell much after landing. So it's Win&Win #YOLO. :D 

Edited by Funky
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On 6/28/2022 at 11:39 PM, Dosingpsychedelics said:

Are you using a fast charger ?if so have you tried switching back to your stock charger 

It's a 2 amp charger, so I don't think it's a fast charger.  Here's an actual image of the charger I have.  https://imgur.com/a/pNwXfXg

 

Aw man it sounds like I'll need to either find someone experienced to fix it or someone who will be willing to buy it and take on a repair project.  

 

I want to note that the wheel started acting up about a week after my port cover got torn off.  Maybe it has to do with debris or damage of the port as well?

 

If not, I definitely did have some bad habits that include the following.   I'm definitely going to take better care of my next wheel  (actually have the Master on preorder)

1. Leaving wheel at 100% for multiple days without riding it

2. One somewhat serious fall at around 15 mph about a month prior to the wheel acting up.

3. Leaving the charger plugged in overnight.

4. Pushing the wheel with multiple overheat warnings.

5. Being lazy and not catching the wheel in <3 mph falls

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3 hours ago, Zutto said:

It's a 2 amp charger, so I don't think it's a fast charger.  Here's an actual image of the charger I have.  https://imgur.com/a/pNwXfXg

The picture reads 3A ;)

Should not matter - but of course there could be some charger malfunction ...

3 hours ago, Zutto said:

Aw man it sounds like I'll need to either find someone experienced to fix it or someone who will be willing to buy it and take on a repair project.  

You have the steps for checking whats the problem described in  

 and in my topic you cited in the beginning.

If you do not check it, one has the possibility that both batteries are bad. As discussed before, deducting both batteries means more or less  selling it for nothing... :(

3 hours ago, Zutto said:

I want to note that the wheel started acting up about a week after my port cover got torn off.  Maybe it has to do with debris or damage of the port as well?

Most likely not. Such failures should be more like no charging possible at all.

3 hours ago, Zutto said:

If not, I definitely did have some bad habits that include the following.   I'm definitely going to take better care of my next wheel  (actually have the Master on preorder)

1. Leaving wheel at 100% for multiple days without riding it

2. One somewhat serious fall at around 15 mph about a month prior to the wheel acting up.

3. Leaving the charger plugged in overnight.

4. Pushing the wheel with multiple overheat warnings.

5. Being lazy and not catching the wheel in <3 mph falls

Although EUCs take some unbelievable beatings, with some bad luck an incident can conpromise a battery.

Most EUC have no real physical protection for the batteries.

PS.: The forum is huge and there is more than enough space to discuss whatever comes into ones mind - so please do not dillute @Zutto's topic!

It's not helping him to solve his problem.

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7 hours ago, Zutto said:

Leaving wheel at 100% for multiple days without riding it

That is not a problem. If you do it for 3 months, maybe. But not a few days.

7 hours ago, Zutto said:

Leaving the charger plugged in overnight.

Not a problem!

7 hours ago, Zutto said:

Pushing the wheel with multiple overheat warnings.

Warnings are just that, warnings. Pretty sure it would stop if it overheated more. Also, that is unrelated to batteries.

7 hours ago, Zutto said:

Being lazy and not catching the wheel in <3 mph falls

So what? Would be very bad luck if that were the cause.

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Don't blame yourself. You just seem to have a bad battery pack.

-

Have you tried running the wheel with each battery pack connected alone (just unplug everything else) and then charging? That would be the first step towards finding out if it is a battery pack problem (instead of a charger problem), and which pack is bad (if one is).

Edited by meepmeepmayer
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5 hours ago, Chriull said:

The picture reads 3A ;)

Ah yes I can't read lol.

@Chriull

@meepmeepmayer

I plan to open the wheel up this weekend and will give an update.  Hopefully it isn't too much more difficult than wiring a motherboard to figure out how to disconnect the battery pack.  

 

Thanks for the help everyone has given me so far.

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29 minutes ago, Zutto said:

Hopefully it isn't too much more difficult than wiring a motherboard to figure out how to disconnect the battery pack.

There is a battery pack in each side of the EUC. Try opening the right-foot side first, and identify the group of wires that come out of the battery pack. Disconnect all of those, and the result will be: the right-side pack is disabled, and the left-side pack remains connected. Proceed with troubleshooting from there.

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1 hour ago, Zutto said:

Hopefully it isn't too much more difficult than wiring a motherboard to figure out how to disconnect the battery pack.  

Nah, it's super simple and visual, once you get over the bump of unfamiliarity with things and the annoyance of "Why do I have to do this scary crap, why can't it just work?!". Stay calm and take your time.

It is just a matter of looking where all the cables go. Somewhere there is a Y-cable where two batteries go into one to-the-board cable (which should end in one black and one red cable soldered onto the board). Trace that Y-cable out from the board. There's big yellow connectors where the battery packs plug into that Y-cable. Disconnect, done. There are also some smaller balancing/communication/charging/whatever cables (between packs, I think), same idea, just figure out where these cables go and disconnect the respective connectors if that makes sense (just don't disconnect the charging, between the charge port and the packs, and then wonder why nothing charges;)... but try to sever all connections between battery packs). You may not have to disassemble anything except opening the wheel und unplugging some connectors. But taking one pack completely out of the wheel is the best guarantee that it's doing nothing. You can just go by that in choosing what to disconnect.

(Same general idea if you have the 2700Wh Nik with 3 packs instead of two, or if the cable layout is somehow different than I think. Just figure out the cables and unplug where needed.)

If i helps, watch some videos to understand things: https://www.youtube.com/results?search_query=gotway+nikola+disassembly

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With each pack alone in the wheel, you'll see what you see. If both packs individually alone in the wheel don't charge further, they are both broken (unlikely) or it's just the charger. If one pack charges to full without the other, that is the good pack and the other one has the bad cell.

Standard warning (again, so many people have said it already): do not re-connect battery packs once one has been charged but the other has not been charged to the exact same state. Unless you like fried electronics.

Edited by meepmeepmayer
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Was way easier than I thought.  The 3 plugs were all visually distinct.  I diagnosed it as the left battery pack having dead/dying cells as the charges to 100V with just the right battery pack connected.  Someone asked earlier about the age.  I'm the second owner but I think it was purchased from euco.us in Nov 2020.  Not sure about miles but I think it's definitely over 1000+ miles.  Same parts though the motherboard was upgraded with OTA updates and tire was changed once.

 

Does anyone know where I can get a battery pack replacement?  I have the 1800 Wh Nikola+ 100V.

 

Thanks for the warnings.  Will not be reconnecting the bad battery pack.

Edited by Zutto
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Too bad it wasn't just a charger problem (one can always hope). But now you know.

1 hour ago, Zutto said:

Does anyone know where I can get a battery pack replacement?  I have the 1800 Wh Nikola+ 100V.

You need a standard 900Wh 100V Begode battery pack. They're the same in so many wheels - Nikola, RS, EXN, Monster Pro etc. - so it is not a Nikola-specific pack. This should be a very common part.

I would ask ewheels (mentioning the wheel was originally bought from them). And other dealers. They sell a lot not listed on their sites, and asking is free. Alienrides even lists one here: https://alienrides.com/products/begode-samsung-50g-900wh-replacement-battery-pack it is $850 though:cry2: (Not sure what the difference between 50E and 50G cells is, ask them. Figure out and match the cells of your packs - there should be a sticker on the packs.)

Maybe someone also sells a used pack (with a nicer price), it cannot hurt to ask in the Private Sales forum: https://forum.electricunicycle.org/forum/24-private-sales-secondhand/

And of course there is the repair option, possibly just one single cell needs to be replaced. No idea who does that though. Check for general battery repair establishments I guess (and Alienrides, I think they have a repair shop).

Just ask around a lot:)

1 hour ago, Zutto said:

Not sure about miles but I think it's definitely over 1000+ miles.

1000 miles is nothing. You were simply unlucky with your bad cell. You did nothing wrong.

Edited by meepmeepmayer
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For anyone still curious.  I did cut open the shrink wrap and try to measure individual cell voltages. It's arranged in two sides with 24 cells each side.  The cells are in groups of 4 inside the pack.  Not sure if I'm doing it right, but I tried every combination of cells between groups that were next to each other.  They all measure 8.4 volts on the right side and 8.3 volts on the left side.  The 24 * 0.1 difference is 2.4 volts.  With some error, that could explain the voltage difference.  Though I'm confused what kind of issue would cause one entire side of cells to have reduced voltage.

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On 6/29/2022 at 4:20 AM, Zutto said:

 It only charges to 96.5V now (~85%).  

 

5 hours ago, Zutto said:

They all measure 8.4 volts on the right side and 8.3 volts on the left side.  The 24 * 0.1 difference is 2.4 volts.  With some error, that could explain the voltage difference.  Though I'm confused what kind of issue would cause one entire side of cells to have reduced voltage.

2.4V vs ~4V is a bit much of an error...

5 hours ago, Zutto said:

I did cut open the shrink wrap and try to measure individual cell voltages

So the BMS PCB is accessible, too?

There should be big solder joints were the nickel strips from the cells are soldered to the pcb. They normally are labeled something like B0 or B-, B1 ... B24. There should be 25 of them and between each two in succession should be 4.2V.

Like in the picture in this gotway bms topic 

a 16s bms is shown. The points to measure would be B- to B1, B1 to B2,... until B15 to B16. 16 voltages between 17 solder joints.

My assumption is, that by measuring at the cell groups you "missed" two/four cell groups. Looking at the picture of the bms, by measuring the outside contacts one misses B- (B0) to B1 and B15 to B16. And between B7, B8 and  B9 on the other side (maybe)?

 

PS.: If the additional measurments show 24 more or less well balanced cells with "just" a little bit too low voltage you could try to unplug the fully functional battery and plug at this connector the non fully functional battery.

If it then charges to 100% the fault could be somewhere between the connector and the charge plug.

If it still does not charge to 100% it could be the BMS - since you opened it already do a thourough visual inspection for any irregularities!

PS.: Be careful messing with the "open" battery - one does not want to short circuit (by accident) 900Wh li ion cells...

Edited by Chriull
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20 hours ago, Chriull said:

 

2.4V vs ~4V is a bit much of an error...

So the BMS PCB is accessible, too?

Well the multimeter does have an error of up to .1 volts so maybe with the error the discrepancy is up to 24 * 0.2 V = 4.8V.  I have a picture where I circled the pairs that I measured previously. https://imgur.com/a/UHSeUsT

 

I was/still am pretty lost so thanks for the image of the BMS.  I didn't know it looked like that on the bottom, would you call it a circuit board or is it something different?  Whatever it is called, it looks pretty much the same as the one i have (2nd image in link)

 

Today, I just measured all the solder joints in succession and they all have 4.19V.

Edited by Zutto
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13 hours ago, Zutto said:

I was/still am pretty lost so thanks for the image of the BMS.  I didn't know it looked like that on the bottom, would you call it a circuit board or is it something different? 

Yes - that's a P(rinted)C(ircuit)B(oard)

13 hours ago, Zutto said:

Whatever it is called, it looks pretty much the same as the one i have (2nd image in link)

With yours B24 is called B+, so the points to measure are B- to B1, B1 to B2, ... B22 to B23 and B23 to B+

13 hours ago, Zutto said:

Today, I just measured all the solder joints in succession and they all have 4.19V.

If the 24 voltages between the 25 measurement points are all 4.19V, the li ion cells are in a perfectly fine condition!

The next step is now to determine if the bms has a problem or the connectors/wiring/... :

On 7/2/2022 at 8:18 AM, Chriull said:

 If the additional measurments show 24 more or less well balanced cells with "just" a little bit too low voltage you could try to unplug the fully functional battery and plug at this connector the non fully functional battery.

If it then charges to 100% the fault could be somewhere between the connector and the charge plug.

If it still does not charge to 100% it could be the BMS - since you opened it already do a thourough visual inspection for any irregularities!

PS.: Be careful messing with the "open" battery - one does not want to short circuit (by accident) 900Wh li ion cells

 

Edited by Chriull
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If they measure 8.3 on one side only it means you have half of the groups at around 0.1/2 v low. (Div by 2 because you're measuring them in pairs.)

12 groups * 0.1/2 = 0.6v.

That pack has 100.8-0.6 ~ 100.2v and it's essentially 100%.

You can confirm by measuring its total voltage.

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7 hours ago, alcatraz said:

Sounds like you might have opened up the wrong pack. 

I double checked and it's the left pack that has issues.  My euc is at 100v with just the right pack connected. 

 

9 hours ago, Chriull said:

 If the additional measurments show 24 more or less well balanced cells with "just" a little bit too low voltage you could try to unplug the fully functional battery and plug at this connector the non fully functional battery.

I tried using the connectors from the right battery pack and it still won't charge to full.

I also did a visual inspection and the only strange thing I could find is the attached image.  idk if that's just rust or maybe corrosion.

 

20220703_120723.jpg

Edited by Zutto
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