WARNING!!! genuine Leaperkim Veteran-450 5A charger can fry itself and the Sherman's control board! (You can open the charger and look at its capacitors to see if you are affected. Be careful.)

[fbhb]

13 hours ago, Benjaminjhobbs said:

I don’t know about my resistors in the charger but now I am concerned if I get a new control board which they will ship out soon, that it is possibly my charger that is the issue? Any update on this?

Well I do have some news/an update, but it is NOT at all good or what anyone on these forums/Veteran Sherman owners would want to hear!  Only after finally getting confirmation from Veteran recently, via my seller that the "smaller" 150uf capacitor replacement Leaperkim Veteran-450 5A charger that I was sent would be safe to use, I went ahead and used it on my Sherman! 

My gut instinct up until this point, had been to carry on using the 220uf Leaperkim charger that had proved reliable after clocking up over 2,000kms and with between 15 to 20 Full charge cycles to 100% each time since installing the New control board.  But having paid the additional cost of a second charger I really needed to know that the New replacement was "safe" to use for any potential future use!  

More Fool Me, the Brand New replacement 150uf charger has now taken out the charge circuit on the replacement control board yet again, in the exact same way as previously (i.e. when the charger is plugged in will Only display "E CHAr"/will not allow the wheel to be charged), so I'm back to square one waiting for who knows how long to get this resolved once more! 

I'm currently waiting to hear back from my seller and Veteran's engineer regarding the replacement of my second control board/safe use of any of these YZ-Power re-badged chargers (in particular the 150uf version), but I am definitely looking to avoid these 5A YZ-Power re-badged chargers altogether and invest in a very expensive Grin Cycle Satiator 360W 72V 5A. 

Edited March 10, 2021 by fbhb

[Rolzi]

I Bought 500w quick charger from Eunicycles to use with my Sherman. 

It has some serious beefy Capacitors 1000uf! 

Here are some images: https://imgur.com/a/DxkNiS5

[Planemo]

6 hours ago, fbhb said:

Well I do have some news/an update, but it is NOT at all good

Unbelieveable. Despite this incredible setback for you, all I can say is Thank You, simply for taking one for the team.

I am right on the edge of ordering some decent Nichicon 220uf caps for mine and replacing them just for the hell of it even though my YZ charger has been fine (6A dual board) on my MSX.

If I was using the 5A single board on a Veteran it would be a no brainer, and I would advise everyone with the same setup to get them replaced asap.

[Planemo]

2 minutes ago, Rolzi said:

I Bought 500w quick charger from Eunicycles to use with my Sherman. 

It has some serious beefy Capacitors 1000uf! 

Here are some images: https://imgur.com/a/DxkNiS5

They are 100uf...not 1000uf...??

Edit sorry I looked at the 1st pic only.....!

Edited March 10, 2021 by Planemo

[null]

Terrible to hear @fbhb sorry for you. Whatever the reason is, caps or not, YZpower have some quality issues with these chargers.  Of my two 150uf chargers one has done close to 2000km of charging, but that could just be random luck. I won't be using it if I can avoid it. Veteran should also review their boards resilience.

I have ordered a XieTong C1200 (1200W) which I hope will behave better. It is the same chargers that Eunicycles use as base for their version. While there is no quality guarantee, at least it's not YZ.

As for the Chargery it was impossible to get to know what the issue was with the Sherman boards, so I'm not risking 300€ there. Especially that they also have their share of "charger going pop" issues.

Edited March 10, 2021 by null

[DavidB]

This has been an interesting read. Is it possible that this could be a result of a voltage surge/spike at fbhb's residence and not YZ chargers quality control? There must have been hundreds of Shermans sold without charging problems yet fbhb has fried 2 in quick succession. I don't know how reliable/stable NZ's grid power is but those 7.1 and 8.1 earthquakes may have had some effect or there could be a local issue causing spikes and surges. Just a thought.

[fbhb]

10 hours ago, DavidB said:

Is it possible that this could be a result of a voltage surge/spike at fbhb's residence and not YZ chargers quality control?

I can definitely say that the chance of this being caused by a current spike at my residence is extremely unlikely, with the random build and very poor quality control or lack thereof regarding the YZ-Power chargers being the most likely culprit!  @DavidB, maybe you have not read through the whole of this thread or referenced @null's very similar experience, along with others that have commented with their own findings but the evidence IMHO is clear that these chargers are highly suspect.

Also given that these Leaperkim Veteran-450 5A chargers have so far been found to be built using either: 150uf capacitors, 180uf capacitors or 220uf and in some cases one of the resistors missing next to the capacitors, etc. etc. really does smack of:  "Hey, what parts do we have in stock at the moment for the next batch order we're working on?  Oh well, never mind if we are some components short and they are not All going to be built the same, let's just use up All the random parts we have left in stock currently!!!"

Before the first control board failure, I charged a couple of times with the Leaperkim 220uf charger without issue and then with the 150uf charger which instantly took out the control board.  Due to that initial experience, after I installed the New replacement control board, I purposely ONLY charged with the 220uf charger from around 20% up to 100% successfully on between 15 and 20 occasions. 

Coincidentally, @Seba had just released his latest version of EUC World and so I have been able to use the "Charging Control" feature of that app for each and every charge since the New control board install.  One of the features this provides is logging of the charging status each time the wheel is charged and then the option to view that log in Excel.  I have back referenced All my logs to see if anything was untoward regarding the household voltage and found there to be be No obvious spikes that could have led to the second, replacement 150uf charger damaging the replacement control board 2 weeks ago! 

Now that is Not to say that the lower capacitor 150uf Leaperkim chargers are Not operating way Too close/border line when on 240volt household supplies, particularly when @YZPOWER have recently commented that the 220uf version will operate at up to 260volts!  

I'm not an electrical engineer, I'm a mechanical engineer but I can very easily distinguish poor build quality internally when I see it, be that mechanical or electrical! 

Edited March 11, 2021 by fbhb

[fbhb]

12 hours ago, null said:

Terrible to hear @fbhb sorry for you. Whatever the reason is, caps or not, YZpower have some quality issues with these chargers.  Of my two 150uf chargers one has done close to 2000km of charging, but that could just be random luck. I won't be using it if I can avoid it. Veteran should also review their boards resilience.

Thank you for your good wishes, as I know you have first hand knowledge of just how this feels.  As I have stated in my reply to @DavidB, I'm by No means highly qualified on the electrical side of things, but Veteran really do need to sort this out in the long run. 

In No way or any scenario should a dodgy charger be allowed to take out the control board charging circuit!  Surely they will be able to add in some kind of safeguard, so that at least your wheel does Not get rendered inoperable should the charger fail! 

I'm still waiting to hear some News from the Veteran engineer regarding my situation and how they intend to resolve it and will update the thread once I hear something.  Are you still waiting for your replacement control board to arrive, I would imagine you are?

Edited March 11, 2021 by fbhb

[null]

Thanks @fbhb, yes still waiting, they took forever to send it out, but it should soon be there. Looking forward. Hoping you get yours soon too. Lucky we have other rides in the meantime.

[fbhb]

32 minutes ago, null said:

it should soon be there. Looking forward. Hoping you get yours soon too. Lucky we have other rides in the meantime.

Good news that yours is not too far away.  I'm not holding out too much hope that I see mine anytime soon though, with still waiting to hear from the Veteran engineer what they are likely to do in the case of Two board failures!

Yes, you definitely have to have other wheels in order to satisfy the urge to ride when one is out of action for whatever reason.  I've just finished a couple more mods to my S18, studded pedals and padded body panel protection so I may also create a New topic for those that may be interested.

Edited March 11, 2021 by fbhb

[Brendan "nog3" Halliday]

Just out of curiosity, has anyone else with noticeable charger/charge circuit issues had the e-loy unbalanced packs issue?

[Benjaminjhobbs]

On 3/10/2021 at 9:40 PM, Brendan "nog3" Halliday said:

Just out of curiosity, has anyone else with noticeable charger/charge circuit issues had the e-loy unbalanced packs issue?

If you see my post below, I had them in reverse, e-loy/bt-Lou and then e-char with a fried board: 

On 3/9/2021 at 1:26 PM, Benjaminjhobbs said:

I am a little concerned with all this. Just a few days ago I got the dreaded bt Loy error indicating an imbalanced pack. After eWheels sent out a replacement battery, the original good pack stopped charging. Then the new pick that they sent, after being plugged in for a little, I got “e char” on the screen.

After hearing about the potential charger issues I looked into this charger from eWheels: https://www.ewheels.com/product/100-8v-4a-rapid-charger-gotway-msx-nikola-monster/. I was originally looking at it because of the higher quality and wanting to replace the YZ charger I had. But then, I got to doing some research on li-ion batteries (https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries) and it is striking to me how detrimental it is to them to be charged up to 100% (4.2v per cell). This might be common knowledge to others, but if you take a look at some of the graphs in the battery university article, there is a clear cycle/life difference between batteries charged up to 100% vs 80% and also the DoD or Depth of Discharge. I am planning on using the eWheels charger to hopefully prevent me from frying the new control board that’s currently in the mail, but also set it to only charge their Sherman to 80% (roughly 3.9v per cell). Then, according to the attached resource on the battery indicator, once I have only 6 bars left on screen, I am at 20%. It would  be at this point I would stop riding and plug back into the charger. That way I am always between 20-80% charge which is one of the ideal ranges for longevity with li-ion batteries. 

If I can get 14,000 cycles, say even just at 10mi a cycle (which is WAY under estimating), I could potentially put over 140,000 miles on this wheel which is what I hope as I sold my car for it to get around! I am sure the motor bearings would be sooner to leave at that point than the batteries. That said, with the price of the replacement parts (https://www.ewheels.com/parts/#products_categories_row_229) the motor is $342 vs the batteries at $1175 a piece! Then again, with solid state batteries in the works…. These wheels are going to start looking and being priced way different. Li-ion is going to get MUCH cheaper and any wheel daring to make their supply from a SD battery will be so much thinner, lighter, and with greater range than we have seen  yet… 

Enough of my rambling... I got to go to work lol 

 

Edited March 12, 2021 by Benjaminjhobbs

[Tawpie]

A couple three things to think about before you deep dive into a couple of other threads on this forum:

1. Cadex, in their batteryuniversity articles, is addressing the characteristics of a single cell, not of a pack of cells. This is important because a pack of batteries must have its individual cells operating at the same voltage or premature aging of an individual cell can happen. This is referred to as "balancing the pack". The cheap and cheesy way this is done in EUCs requires 4.2V be continuously applied to each cell—those that are slightly stronger will have their charge (and voltage) bled off while the other cells in the pack keep charging and catch up. The charge cycle is complete when the charge circuit believes all cells have reached 4.2V but this is crudely determined and a bit of a crap shoot. But you're trying to hold each cell at full charge until all the cells reach full charge.
2. [EDIT: these numbers are all wrong (thank you @null!), ignore this paragraph!] Cadex is also referencing 80% state of charge of a single cell, not the EUC reported '%' of a battery pack (think of the reported % as the remaining percentage of full range, not state of charge). Consequently, 80% state of charge is 4.2 * 0.8 = 3.36 V/cell. Stack 24 cells as is the case in the Sherman's 100V pack and this means 80% state of charge is 24 * 3.36 = 80.64V... which reads something like 4% on the Sherman display. According to the chart you included, when you charge to 80% on the display, you are at a pack voltage of 95.52V, or 3.98V/cell. The reason 80% state of charge is reported as 4% by the Sherman display (and all EUC reporting mechanisms) is that the EUC manufacturers must preserve margin above the 2.5Vish low limit on each cell. If they don't reserve this margin, your chances of causing physical damage to a cell go up "a lot" as the charge gets lower and lower. Maintaining margin against too low voltage means the EUC manufacturers choose a higher voltage to represent 0% capacity than the one that represents truly-empty-cell-damage-and-fire-will-result-if-you-go-lower. You'll find that the 0% threshold is chosen to lie between 3V and 3.15V per cell.
3. [EDIT: these numbers are wrong (thank you @null!), ignore this paragraph!] A "cycle" refers to a full charge/discharge event of a single cell, (4.2 to 2.5ish V). Partial cycles sum up into full cycles, unlike NiCad. If you run your Sherman between 100% and 0% remaining range, you're really only discharging to about 3V/cell. A full cycle is a voltage change of 4.2 - 2.5 V = 1.7V. At a 0% remaining (3V, which is 1.2V below full), you've used 1.2 / 1.7 = 70% of a charge cycle. So even though you charge 14,000 times, you're only burning up 14,000 * 0.7 = 9882 cycles. You won't like those last several thousand cycles though, but by then maybe the Sherm will only be used for mailbox runs anyway.

Each of us has to draw our own conclusions on how to handle our charging. But check out discussions on pack balancing 

and on how to charge

 

Edited March 14, 2021 by Tawpie
wordsmithing

[null]

@Tawpie 2: Wouldn’t “SOC” in % be estimated within the cells operating range, and not starting at 0v? Nominal Voltage being ~50% (?)

Edited March 13, 2021 by null

[Tawpie]

Cadex is almost certainly referencing “just before cell damage” as 0% SOC, our wheels are Never allowed to go that low. 3V per cell is “walk”.

[Tawpie]

But you have a very good point. Cadex may very well be referencing 80% of 4.2-2.5 volts so my numbers are probably all bogus. I’ll recompute after nap time.

Edited March 13, 2021 by Tawpie

[Tawpie]

recomputing... Reading Cadex's "depth of discharge" article, they reference 3.0V for LiIon as "discharged", because at that point 95% of the energy is gone and further current draw will cause the cell voltage to fall very rapidly. Which means, my numbers above are horse hockey. Next time, I'll double check my assumptions!

[Chriull]

3 hours ago, null said:

@Tawpie 2: Wouldn’t “SOC” in % be estimated within the cells operating range, and not starting at 0v? Nominal Voltage being ~50% (?)

Cadex means the real state of charge, which in a wide range can be nicely approximated by the cell voltage after enough settling time.

Just around low percentages the "linear" correlation gets lost.

1 hour ago, Tawpie said:

Cadex is almost certainly referencing “just before cell damage” as 0% SOC,

Cell damage happens everywhere above and below the "intrinsic median" cell voltage, as far as i have understood their articles.

Of course especially at 0% and if current is forced through an empty cell!

1 hour ago, Tawpie said:

our wheels are Never allowed to go that low. 3V per cell is “walk”.

In average. Once one cell is weaker/more aged/degraded as the others it gets repeatetly pushed far below 3V if an euc pack is burdened to low percentages.

Afaik all wheels beside "newer" ninebots have no single cell undervoltage warning/supervision. Imho a gross negligance!

1 hour ago, Tawpie said:

But you have a very good point. Cadex may very well be referencing 80% of 4.2-2.5 volts so my numbers are probably all bogus. I’ll recompute after nap time.

Exactly. And most probably they regard all the non linearities between cell voltage and state of charge. This are just two values characterising a cell. And in some ranges they have a quite linear correlation. Afaik you should restrict it to some 4.2V-3.0V and ~100%-2x% . Depending on the specific cell characteristics

 

 

[Mantraguy]

I read through this thread previously, but a few days ago I thought of something. It seems that most (maybe all?) of the people here who have had the YZ Power charger cause damage to their Sherman control boards are in countries with 230v - 240v household mains (New Zealand and Europe iirc). Has anyone experienced this fault while charging from 120v mains (North America)? Just curious if there might be a correlation here...

[fbhb]

3 hours ago, Mantraguy said:

Has anyone experienced this fault while charging from 120v mains (North America)? Just curious if there might be a correlation here...

I believe @Ben Kim may have been one of the first to have fallen foul of this exact same issue (he will correct me if I'm wrong), so that would be at least One owner charging from 120v mains that I'm aware of.

From my own personal experience, added to New information I have been made aware of from Veteran via my seller, the common denominator has Always been YZ-Power chargers with 150uf capacitors, but that it is not to rule out that they simply cannot operate reliably at 240volts! 

My supplied 220uf capacitor charger behaved perfectly fine on 240 volts, whereas in my case 2 separate 150uf chargers have taken out the charge circuit on my Sherman's control board, so go figure?

Random build quality and components, poor assembly methods and comments made by @YZPOWER themselves elsewhere confirm that the charger's have had very poor QC, that they now intend to improve upon.  Owners of Sherman's have also found it possible to have been supplied with a Leaperkim Veteran-450 5A charger that has either 150uf capacitors, 180uf capacitors or 220uf, how random is that?

From information I have been given very recently, Veteran now has 220uf capacitor chargers available for the replacement in my own case and hopefully that also becomes the standard issue in their future supply.

However, even with this improvement to the Leaperkim version of the 450 chargers I have totally lost confidence in the YZ-Power being supplied by Veteran and have already ordered a high quality Grin Cycle Satiator 360W 72V 5A. for when my SECOND replacement control board finally arrives.

Edited March 27, 2021 by fbhb

[Ben Kim]

44 minutes ago, fbhb said:

I believe @Ben Kim may have been one of the first to have fallen foul of this exact same issue (he will correct me if I'm wrong), so that would be at least One owner charging from 120v mains that I'm aware of.

From my own personal experience, added to New information I have been made aware of from Veteran via my seller, the common denominator has Always been YZ-Power chargers with 150uf capacitors, but that it is not to rule out that they simply cannot operate reliably at 240volts! 

My supplied 220uf capacitor charger behaved perfectly fine on 240 volts, whereas in my case 2 separate 150uf chargers have taken out the charge circuit on my Sherman's control board, so go figure?

Random build quality and components, poor assembly methods and comments made by @YZPOWER themselves elsewhere confirm that the charger's have had very poor QC, that they now intend to improve upon.  Owners of Sherman's have also found it possible to have been supplied with a Leaperkim Veteran-450 5A charger that has either 150uf capacitors, 180uf capacitors or 220uf, how random is that?

From information I have been given very recently, Veteran now has 220uf capacitor chargers available for the replacement in my own case and hopefully that also becomes the standard issue in their future supply.

However, even with this improvement to the Leaperkim version of the 450 chargers I have totally lost confidence in the YZ-Power being supplied by Veteran and have already ordered a high quality Grin Cycle Satiator 360W 72V 5A. for when my SECOND replacement control board finally arrives.

I didn’t even bother checking the caps, it started charging at 2.1A instead of the typical 4.4, got a new charger from my seller and it’s been good since; i chucked the old charger so I can’t even check for you guys. 

[Mantraguy]

18 hours ago, Ben Kim said:

I didn’t even bother checking the caps, it started charging at 2.1A instead of the typical 4.4, got a new charger from my seller and it’s been good since; i chucked the old charger so I can’t even check for you guys. 

 Thanks for weighing in with your experience. So your charger just supplied low current, but didn't fry a control board? 

[Chriull]

22 hours ago, Mantraguy said:

I read through this thread previously, but a few days ago I thought of something. It seems that most (maybe all?) of the people here who have had the YZ Power charger cause damage to their Sherman control boards are in countries with 230v - 240v household mains (New Zealand and Europe iirc). Has anyone experienced this fault while charging from 120v mains (North America)? Just curious if there might be a correlation here...

Just as a sidenote: from what i found in a quick internet search yzpower chargers are specified for 100-240Vac.

At least here in Europe mains voltage is 230Vac +/-10%! So it can validly go up tp 253V.

So as stated from the @YZPOWER the lower capacitors are more susceptible to surges people with mains voltage reaching the upper limits could be the one with bad luck?

Maybe exchanging to bigger capacitors could help (pfff... A _dangerous_ thought without knowing the schematics...) or better just some 240/120V transformer/inverter!

[Ben Kim]

2 hours ago, Mantraguy said:

 Thanks for weighing in with your experience. So your charger just supplied low current, but didn't fry a control board? 

Correct, however i live in the USA where its 110V. 

[null]

3 hours ago, Ben Kim said:

Correct, however i live in the USA where its 110V. 

232V here.. Probably not too much spikes (city).