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]

Way back in September last year, I added a second genuine Leaperkim Veteran-450 5A charger to arrive with my Veteran Sherman order, to give myself the option to quick charge if necessary.  When the wheel finally arrived in early November, I initially Only used one charger at a time to test that both were working correctly.  I think it was most probably only the second time of using one of mine, again just with one on its own, whilst it was nearing 90+% charge I heard a loud "pop" - the charge cycle stopped and I quickly turned off the power supply and unplugged the power lead!  When I had a sniff at the charger to see if I could detect the usual smell of burnt components there was obviously that tell-tale odour most definitely present!

The wheel would not continue to charge with my second working charger plugged in and the display was then stuck on: "ECHAr".  I contacted my seller, who in turn contacted Veteran for advice on the solution to this.  There is also a topic posted HERE where another owner had this very same error message on his Sherman's display, but in his case the wheel was faulty straight out of the box!

Interestingly, after opening the failed charger up, I found that there was a burnt/damaged component right next to the capacitors as well as one of the fuses on the charger's board that had blown when it failed.  Following this, I decided to open up the good working charger to compare the two and found that the capacitors in the failed one were of a much lower uf/size rating than the one that still works (I'm very concerned that this may have been a factor and could also be for other Sherman owners if true!).

Original Leaperkim Veteran-450 5A charger comparison, both with different sized capacitors

I also passed on the above information and the following photos to my seller so that they could share it with Veteran to get the factory's help with their assessment/course of action. 

Unfortunately, I only got to ride the Sherman 4 times before this incident happened and really loved the ride experience, huge range and all the other Sherman highlights that owners had been raving about!

Leaperkim Veteran-450 5A charger that fried, with 150uf capacitors

Leaperkim Veteran-450 5A charger, still working with 220uf capacitors

Now finally, after 2 months of waiting the 2 warranty items have arrived courtesy of communication with my seller and their lengthy communication back and forth with Veteran themselves, to confirm what needed to be replaced!  I have been sent a New control board, which coincidently is changed from my original L20-34 version compared to the New L20-42 version supplied by seller via Veteran and a replacement Leaperkim 5A charger. (comparison photos below show a different/individual transformer board)

Old Control Board is at the Top L20-34. New Control Board is at the Bottom L20-42

Now, given that I already had concerns that whilst one of my chargers had the larger 220uf capacitors and the one that fried only had 150uf capacitors (photos above), the replacement one that arrived also only had 150uf capacitors!  Again, more concern on my part as I had specifically asked what version of the charger I would receive Only to be told by my seller and I quote: “It is the charger of the latest version of capacitor.”  So I decided to contact Veteran directly to try and get some confirmation on which charger is actually their latest version, but as is usual no real clarity was forthcoming (read:  we don’t know, we just get whatever YZ-Power builds for us!!!).  Suffice it to say that Veteran could Only confirm for me what I already knew in my own mind, that the charger with the larger 220uf capacitors was the “better” one to use!

New Leaperkim Veteran-450 5A charger opened up

New Leaperkim Veteran-450 5A charger 150uf capacitor next to the intact component that fried in the first charger

On that basis and on my own feelings regarding the 150uf charger failing initially and almost instantly, I will not be in any hurry to Test or even use the New 150uf charger, especially with a Brand New control board fitted to the Sherman!  My main reason for ordering a second charger in the first place with the wheel, was to give myself the option if required rather than a regular need to charge at 10A and it's also useful to have a back up. 

So from now on I will Only be using the originally supplied 220uf charger for the foreseeable future and hope that it at least offers me some longevity and reliability!

Unfortunately, I am not the Only one to suffer this issue with what is essentially a YZ-Power 450 5A charger frying itself and also taking out the charge circuit on the Sherman control board!

@null very recently posted a topic HERE that I have also commented on, where he had the exact same experience with a YZ-Power 450 5A 150uf capacitor version of the charger and the very same component frying on the charger’s board, also killing off his Sherman’s control board!

As mentioned earlier, getting any firm word on the random build quality/components used and what is actually inside the ‘stock standard’ version of the currently supplied Leaperkim Veteran-450 5A charger is next to impossible!

Every owner of a Sherman needs to be made aware of this potential to not only fry the charger itself, but to render your wheel useless until a replacement control board can be sourced and fitted, which in some cases can be a matter of months!

 

P.S. On the subject of fitting the Sherman control board, it may be common knowledge to most that due to the way the board is mounted to the heatsink, the whole control board assembly will not come out of the bay without either splitting the wheel or dismantling just the board from the heatsink!?

I was able to make a small mod to the Sherman’s control board bay to allow the board’s easy removal/fitting should I ever need to remove it again in future.  I have created a separate topic explaining the steps involved in case anyone is interested : HERE

 

 

 

 

 

Edited January 31, 2021 by fbhb

[xSAMCOx]

Thank You for the info  the Sherman been on my top coice on my next wheel. But think ill hold on slight n se how this turns out if this is a spread problem for more owners. Noting is  perfect but id like to avoid a fire.

 

[Chriull]

1 hour ago, fbhb said:

Way back in ...

There seem to be some problems with your pictures permissions - can't be seen here by me.

[fbhb]

5 hours ago, Chriull said:

There seem to be some problems with your pictures permissions - can't be seen here by me.

Yes, I'm aware about the photos and will get it sorted in due course (they are Only showing for me in this and my other posts too, unfortunately! Thanks for your help and Cheers)

[.....]

I am not surprised at ANY of this. My stock charger came beat up and weighs about as much as a fart. I guess I need open it up and check caps. Lord knows Ive a crap ton of QUALITY caps laying around. How odd that a basic consumer has better parts in his junk bin, than a manufacturer.  Luckily I've been using an e-wheels charger mostly, but the stock I used once or twice as it tops off at a tad higher voltage than the other. Its simply amazing how much lack of organization and tracking of parts these companies have. The standard 'we dont know, someone else built it for us' is such a shitty excuse. The sum of the parts is the liability of veteran, and not being able to tell us whats in what, really tells you a lot about them, doesnt it? Yet ANOTHER euc company that cant get their shit straight or cant help but be vague and basically useless when it comes to specific information. You know, quality nichicon caps arent expensive, when you factor in what a control board or burned down apartment complex could cost. Cost even more if fatalities are involved. .. Oh wait, NONE of these Euc companies accept much liability do they? So depressing that evey good idea from EVERY euc company, is undone by something rediculously stupid.  If something is only as valuable as its weakest part, ALL of us pretty much paid for overpriced turds...  Cmon, SOMEBODY build a basic euc and do it right. Seriously, the euc is mature enough now that SOMEONE can make a decent wheel and check ALL of the pieces everytime, before selling. This bullshit passing off the issue as 'we used a 3rd party', is not an acceptable reply. Hell, even the modular plug (trs) is wired to blow shit up by crossing points. Cmon, isnt someone in this company a whiz at basic electronics, detail oriented? If i don't win the presidency (damnit, i didnt), I'll be accepting offers to become part of a REAL euc build team. I mean hell, you gna need a janitor too. I'll even adhere to a checklist and validate my work daily.

Edited January 31, 2021 by ShanesPlanet

[xSAMCOx]

The sherman is a investment on the price it got its in the high end euc marked ,n become fast the wheel to Get in 2020.

if one look on all the shermans sold vs issues the ratio is still low on faults. 
Oh well just to try to keep up..

 

 

[Planemo]

Thanks for this, I am going to open up my YZ Power 100v 6A charger and see what rating the caps are now...it hasn't given me any problems (yet) but it will be interesting to know..

[meepmeepmayer]

Good investigation! Topic pinned for now. (I also edited the title so people hopefully won't miss this, hope you don't mind.)

You would think a simple charger is know tech nowadays, but apparently it isn't and one has to open the charger up and check the capacitors to be sure it's ok (Be sure you know what you are doing when working on electronics. Capacitors may hold charge, even when the charger isn't plugged in!)

-

Also I'm disappointed there's no safety mechanism in the charger (or wheel, but it should be in the charger). A broken charger is one thing, but it shouldn't be able to fry the board and in the worst case even start a fire if things go completely haywire in the wheel!!

Offtopic, looking at the board pictures: Why do the motor power cables nowadays have these good connectors, but the battery power input is still the same soldered crap?! It's not like there's less current in the battery cables than the motor cables (right?)...

Edited January 31, 2021 by meepmeepmayer

[null]

On 1/31/2021 at 3:27 PM, meepmeepmayer said:

It's not like there's less current in the battery cables than the motor cables (right?)...

I suppose the current from the batteries is smoother as it serve to charge the capacitors, while the current going to the motor do it in bursts. (?)

It seems though that modern EUCs are too powerfull for this small soldered area to take that much current, as both Marty’s overheat hill Sherman and the NYC demo monster vaporized the board right there.

(Thanks for the write up and pictures @fbhb , much clearer than my rant. Besides I only have the smaller caps versions)

Edited February 1, 2021 by null

[meepmeepmayer]

Any idea what the mechanism is behind what happened? Do the smaller capacitors simply get too hot because they are physically too small, and then you get a short?

[Planemo]

Mine are the 150uF Tianchen caps...

Although my 6A charger does run across 2 boards...if I run one board it outputs 3A...maybe the 5A version that Veteran is using is asking too much for one board...dunno...but I haven't had any issues and was running it in direct sunlight on the hottest day of the year last summer, on the longest ride (charged 4 times in a day)

[Planemo]

21 minutes ago, meepmeepmayer said:

Any idea what the mechanism is behind what happened? Do the smaller capacitors simply get too hot because they are physically too small, and then you get a short?

The weird thing is that the caps in the blown charger look OK to me. Usually, a blown cap is very evident because they...well.. blow. Literally. The pressure part (end of the cap with 3 slots) will nearly always show signs of swelling/blown open but in this case it looks fine. It's only the resistor next to it that shows obvious damage.

[null]

Yes its the resistance (?) right besides it that burnt, both on his and my charger.
(marked R3 on the board. On mine both R3 and R4 look burnt)
I do not have enough knowledge to get what is the issue, could be unrelated to the caps for all I know..

( @Planemo with your 2x3A you should probably be safer indeed)

 

 

Edited January 31, 2021 by null

[.....]

8 hours ago, xSAMCOx said:

The sherman is a investment on the price it got its in the high end euc marked ,n become fast the wheel to Get in 2020.

if one look on all the shermans sold vs issues the ratio is still low on faults. 
Oh well just to try to keep up..

 

 

Its not low on faults, if you consider mass production that includes substandard, missing protections and under specd parts.

Its a low on complete operational failure at best.

if one look on all the shermans sold vs issues the ratio is still low on faults. - is exactly what the euc companies are banking on. Being content with such an idea, when poor parts are being used, is exactly why this happens. If you buy a car and a design is KNOWN to have  fatal flaws that could ruin it, would you be happy knowing that it only happens to some? You know, some that are made exactly like what you invested in. If it were something other than poor parts selection, at least we could assume it was an accident.

Edited January 31, 2021 by ShanesPlanet

[xSAMCOx]

52 minutes ago, ShanesPlanet said:

Its not low on faults, if you consider mass production that includes substandard, missing protections and under specd parts.

Its a low on complete operational failure at best.

if one look on all the shermans sold vs issues the ratio is still low on faults. - is exactly what the euc companies are banking on. Being content with such an idea, when poor parts are being used, is exactly why this happens. If you buy a car and a design is KNOWN to have  fatal flaws that could ruin it, would you be happy knowing that it only happens to some? You know, some that are made exactly like what you invested in. If it were something other than poor parts selection, at least we could assume it was an accident.

Its risk vs reward  like if one buys a Tesla the chance is skyhigh on getting faults like poor build quality. Yet the reward is one of the better Electric cars with the best charge infrastructure. 

[Wren]

Thanks for posting these photos! Looks like there has been cost cutting in the Leaperkim chargers. The big caps act as a voltage reservoir to smooth the DC voltage coming from the rectifier. They changed brands and capacitance to save a buck, along with no longer applying anti-vibration silicone around the components. The melted input wires and the two damaged resistors indicates a short on the primary side, likely due to a failed mosfet (against heatsink). I'm speculating now but I think the mosfet probably failed due to heat and I am curious if increased voltage ripple was the cause, or if they made other component changes like the mosfet itself, or if it is not dissipating heat to the aluminum block very well.

 

[.....]

4 hours ago, xSAMCOx said:

Its risk vs reward  like if one buys a Tesla the chance is skyhigh on getting faults like poor build quality. Yet the reward is one of the better Electric cars with the best charge infrastructure. 

I agree completely. For now, the euc game is a risk vs reward.. big time. We all continue to buy into them, even tho we know its a little low on quality and reliability. Theres choices of euc's but sometimes it seems like theres no CLEAR quality choices. Still, they are a choice and its way better than none. However, we arent talking 'cutting edge technology' being the culprit. I undertand that complex systems fail. Trying NEW tech is a dice roll. But a damn wall charger?! Surely this isnt pushing the edge of tech nowadays. Im merely seeing the same thing as always... companies going cheap in critical areas. Blatant disregard for known technologies that have been PROVEN. A lack of proper parts revision documentation or any semblance of a real PLAN to do so. I'm not well versed in electrical components, but surely amperage requirements and protection/fuse devices arent above the realm of a typical electronics engineer? Even if it is complicated, someone has ALREADY done the testing of the components involved, the tendecy of fail at certain tempratures and vibration useage. I could build a mouse trap that works, as the design is proven. Hell, I dont even need know much about it, to just adhere to what someone else has figured out. Ugh, I'm so sick of cheap shortcuts that wind in some stupid small failure. They wouldnt put lamp chord in a tesla. They dont have to even try it to know that, its common knowledge nowdays. I enjoy my wheels so much is why this even bothers me. I hate knowing that Im riding a timebomb and that my pockets may be emptied again very soon.

Edited January 31, 2021 by ShanesPlanet

[Number1stunner]

Large capacitors like that are generally used to filter the powersupply. As such, a little more won't hurt. 

A bad electrolytic capacitor will usually be obvious.

They tend to pop when they go bad. They usually have lines scored on the top, so they "pop" instead of "bang."

Look at yours. If the tops are still flat, then they are most likely OK.

If they are bulged, or some icky stuff has leaked out then they are definitely bad.

Leaperkim themselves say it's fine to charge at 10amps. I charged at 10a and the batteries were fine but it unfortunately blew my rear light and shorted something on the main board to the rear light....

Now I'm running just front headlights and splicing in a rear light with a dual connector (seems to work) until a new board under warranty arrives. The wheel itself seems to be working fine.... Although I am noticing temperature spikes which are quite concerning. 

I don't think the chargers having sightly different micro farads (UF) blew your board. However, maybe like mine the board itself couldn't take the 10a charge🤷🏽‍♂️.... The batteries can though. 

I have noticed new Gotways have serrate boards for the lights to the power now.... Food for thought.....

Diagnosing your original issue is tricky goes beyond my knowledge of boards🤷🏽‍♂️

 

 

[null]

Speaking of diagnosis: I could take some high rez pics of both sides of charger and controller board if anyone think they could get something from it. Or multimeter measurements.

Dead tail light: mine died too, no idea from what but I do (did) charge at 10A. (no noticeable heat) (The charger died when charging alone though)

Edited February 1, 2021 by null

[Ben Kim]

My stock Veteran charger also died on me within a month; seller sent me a new controller within a few weeks.

Fun fact: The stock Veteran charger is rated for 450W, and confirmed with a current monitor to deliver 4.39-4.41A of current, not 5A.  

[Tawpie]

tl;dr it's not at all surprising that a charger failure will take out things connected to the charger, but the value of the big cap should not be the reason. (should is an operative term here BTW)

I used to design switch mode power supplies for a living. The general principal of operation happens in two stages.

1. First, mains voltage is converted from AC to DC at a DC voltage that is higher than what is the final desired output voltage. Let's call this the unregulated DC voltage, it is higher than the desired output voltage.
2. Then, the unregulated DC voltage is converted to the final desired output voltage (DC to DC conversion) by watching the voltage on the big cap until it drops below the desired output level.
3. When that happens, a switch (usually a power MOSFET) connects the unregulated DC voltage to the big cap and the voltage on the big cap rises toward the unregulated DC voltage. This 'refills' the energy in the big cap and the voltage on the big cap rises. Devices downstream of the charger (the charger board in your wheel) are connected to the big cap.
4. When the voltage on the big cap rises above a certain level, the switch connecting it to the unregulated DC voltage is tuned off.
5. All this time the energy in the big cap is being drained out by the charger board in your wheel so after a little while the voltage on the big cap will drop below threshold and the MOSFET will turn on and connect the big cap to the unregulated DC voltage.
6. The cycle is repeated several tens of thousands of times per second.

It's a bit like maintaining a specific water level in a leaky bucket from a garden hose where the hose is either on or off. On for a little, then off.

Depending on the exact architecture of the power supply, if the switch were to get stuck in the "on" position (a shorted MOSFET) or the big cap were to short circuit, there's a high likelihood that the unregulated DC voltage will be connected directly to the charger board on your wheel and if the charger board on your wheel isn't designed to be ok with this, it will go poof. When the charger board goes poof, if the things connected to it aren't designed to expect a poofed charger board, they too will go poof and you have a cascading failure in the downstream components. Advance power supply architectures can limit the ability of a failed MOSFET to destroy downstream devices, but these are more expensive and sometimes require licensing of patents. Brute force cheap architectures assume the cost/benefit ratio favors cost and simplicity.

The capacitance value of the big cap (150 µF or 220 µF) is chosen to satisfy a number of competing requirements: smaller capacitor values mean the MOSFET has to cycle more quickly because the cap stores less energy per cycle and in general the output voltage is less constant. More importantly, it changes the math that controls the on-off and if not done properly the on-off control can literally get the wobbles and lose control of the output voltage or the on-off control might react too slowly to changing conditions. Assuming the control circuit was redesigned for the 150 µF cap, the value should be immaterial. EXCEPT, the 150 µF output cap will probably run warmer than the 220 µF.

Anyway, I wouldn't worry too much about the difference in the cap values... you are still trusting that the charger design is solid. Individual charger components will fail, bad things happen. Usually they only happen to nice people.

[Planemo]

13 minutes ago, Tawpie said:

 Assuming the control circuit was redesigned for the 150 µF cap, the value should be immaterial. EXCEPT, the 150 µF output cap will probably run warmer than the 220 µF.

Good info thanks. I think I'm taking away from that, that simply changing the caps to bigger ones might not be a good move.

That said, I used to be on an eMTB forum and a lot of the guys were blowing the caps in their 2A chargers. Everyone (including me) upped the cap size and they worked faultlessly afterwards, so I guess it can work, just depends on the rest of the circuit I 'spose. As a side note, none of us suffered any controller/battery damage when the caps blew, unlike the Sherman...

[Tawpie]

It's one of those things... the value should have been chosen with care, but there's wiggle room (design margin in the MOSFET control loop stability) so changing the cap value might not harm things. But it's not guaranteed. What typically causes failure of an electrolytic capacitor is "excessive ripple current" which causes the component to overheat. When you choose a cap value that will see high ripple currents, the designer should have spec'd a part with a low ESR (equivalent series resistance) and maybe they did, but purchasing elected to get a cheaper part (or maybe 150 µF was all they could get). You could consider finding a lower ESR 150 µF cap and that would be safe to swap in, or take your chances and replace it with a low ESR 220 µF part and cross your fingers that its stable. Or leave it as is.

But until somebody reverse engineers the charger in detail, it's speculation.

Another big difference between the 220 µF and the 150 µF in your pictures is the lack of the white pucky on the 150 µF. The pucky in this application functions as 'staking', and literally stakes the part to the board so it's less likely to move and snap off at the leads/solder joint. The damage shown in your blown charger has a little bit of a look of arcing underneath the part, the kind of thing that can happen with high voltage and current if the physical connection has been compromised. Said arching would be a bad thing and might or might not take out connected devices. In any case, without the staking the charger is a little more susceptible to shock and vibration than it is with the staking.

 

Edited February 1, 2021 by Tawpie

[Planemo]

1 hour ago, Tawpie said:

The damage shown in your blown charger 

Just wanted to clarify that it's not my charger which has blown (my 6A one is fine). But I might stick some 'pucky' on it anyway

[Marco73]

4 hours ago, Tawpie said:

C'est l'une de ces choses ... la valeur aurait dû être choisie avec soin, mais il y a une marge de manœuvre (marge de conception dans la stabilité de la boucle de contrôle MOSFET), donc changer la valeur de plafond pourrait ne pas nuire aux choses. Mais ce n'est pas garanti. Ce qui provoque typiquement la défaillance d'un condensateur électrolytique est "un courant d'ondulation excessif" qui provoque la surchauffe du composant. Lorsque vous choisissez une valeur de plafond qui verra des courants d'ondulation élevés, le concepteur aurait dû spécifier une pièce avec une faible ESR (résistance de série équivalente) et peut-être l'a-t-il fait, mais l'achat a choisi d'obtenir une pièce moins chère (ou peut-être 150 µF était tout ce qu'ils pouvaient obtenir). Vous pouvez envisager de trouver un plafond ESR 150 µF plus bas et qui pourrait être échangé en toute sécurité, ou tenter votre chance et le remplacer par une pièce à faible ESR 220 µF et croiser les doigts pour qu'il soit stable. Ou laissez-le tel quel.

Mais jusqu'à ce que quelqu'un rétroconce le chargeur en détail, c'est de la spéculation.

Une autre grande différence entre le 220 µF et le 150 µF dans vos photos est l'absence de rondelle blanche sur le 150 µF. Le pucky dans cette application fonctionne comme un `` jalonnement '' et place littéralement la pièce sur la carte afin qu'elle soit moins susceptible de se déplacer et de se casser au niveau du joint de soudure / plomb. Les dommages indiqués sur votre chargeur grillé ont un petit air d'arc sous la pièce, le genre de chose qui peut se produire avec une tension et un courant élevés si la connexion physique a été compromise. Cette cambrure serait une mauvaise chose et pourrait ou non supprimer les appareils connectés. Dans tous les cas, sans le piquetage, le chargeur est un peu plus sensible aux chocs et aux vibrations qu'avec le piquetage.

 

I try to follow your explanations but it is not really my strong point of knowledge, that said I will simply ask a question or a simple question: can not insert a fuse in protection between the charger and the card ???