Jump to content

What do you think about the 100.8V 5A-7A-9A current adjustable charger for gotway?


Recommended Posts

On 5/4/2020 at 2:46 AM, xorbe said:

Ah, you've linked the 84V GX16 4-pin model.  I don't see 100.8V as an option there.  Found it via search (I don't see a way to navigate to it via menus)

https://www.pmbatterychargers.com/900w-1008v-5a-7a-9a-current-adjustable-digital-display-partial-charge-lithium-li-ion-battery-charger-for-100v-gotway-free-shipping-p2579895.html

"Model4" means it has all the goodies.  Clearly there are at least 3 different chargers in the product pics none which match OP's photo, but I can only assume the correct charger as advertised would be sent, since it's a new model.

I checked, all 4 of my pins are wired on my 100.8V Nikola+ 21700.  Betty from pmbatterychargers finally replied via email.

May 30th: order placed

June 16th: order sent via DHL

June 18th: order received

So... how is everyone's new charger doing?  I have an MSP HT now, and was surprised my range isn't as good as my older MSuper VS3+ with a smaller battery, likely because of 2500w vs1500w motors.  

I wanted to check how everyone's is before I order this one.  Thanks!

Link to comment
Share on other sites

8 hours ago, Czestnut said:

So... how is everyone's new charger doing?  I have an MSP HT now, and was surprised my range isn't as good as my older MSuper VS3+ with a smaller battery, likely because of 2500w vs1500w motors.  

I wanted to check how everyone's is before I order this one.  Thanks!

We all have this charger here, it works nice and solid 👍

Link to comment
Share on other sites

17 minutes ago, Ben Kim said:

I own this 5/7/9 charger, works fine charges at the full 9A on both 110/220V (confirmed by voltmeter) however I would not use this charger as a daily driver, as the CV phase doesn’t work properly like the stock chargers that come with your wheels; it will not balance properly. 

For top-offs outdoors it is absolutely perfect for that use case.

Same but the 450W version.
I found it very annoying that it mishandled such a basic feature, and sold it for peanuts as "wonky".

Edited by null
Link to comment
Share on other sites

44 minutes ago, Ben Kim said:

I own this 5/7/9 charger, works fine charges at the full 9A on both 110/220V (confirmed by voltmeter) however I would not use this charger as a daily driver, as the CV phase doesn’t work properly like the stock chargers that come with your wheels; it will not balance properly. 

Really? What is the problem with the CV phase?

  • Like 1
Link to comment
Share on other sites

9 hours ago, Planemo said:

Really? What is the problem with the CV phase?

The taper in CV is way too short, also does not trickle charge when it’s “done” charging. Charger just shuts off when it thinks it’s done, which doesn’t give enough time for the batteries to balance. On stock Gotway/Veteran chargers it will continue to balance at 0.1A for up to 24 hours until it’s truly “done”. 

Like I said, given I only use this charger outdoors, I don’t really mind. 

  • Like 2
Link to comment
Share on other sites

22 minutes ago, Ben Kim said:

The taper in CV is way too short, also does not trickle charge when it’s “done” charging. Charger just shuts off when it thinks it’s done, which doesn’t give enough time for the batteries to balance. On stock Gotway/Veteran chargers it will continue to balance at 0.1A for up to 24 hours until it’s truly “done”. 

Like I said, given I only use this charger outdoors, I don’t really mind. 

I hear you. But wasn't this issue identified only with the Shermans charging system?

Link to comment
Share on other sites

2 hours ago, Planemo said:

I hear you. But wasn't this issue identified only with the Shermans charging system?

It has nothing to do with the Sherman’s BMS or charging sequence. The charger shuts itself off after it tapers. no trickle for balancing and it’s too short. I’ve used this same charger on a Monster Pro, same thing. 

As stated, these are great for topping off on a long ride, but I would not use it as an at-home charger replacement. Besides, you can buy YZpower “stock” chargers for $50 on Aliexpress. 

edit: if you absolutely must have the most charge possible, I’d drop down to 5A when the wheel is at 100V or so. Fully charging at 9A will net you something like 98.8V vs 100.2v by finishing it off at 5A. 

Edited by Ben Kim
  • Like 2
Link to comment
Share on other sites

20 minutes ago, Ben Kim said:

It has nothing to do with the Sherman’s BMS or charging sequence.

Fair enough. I thought I read it somewhere on the forum that this issue was occurring with the Sherman only.

I have had 84v and 100v YZ chargers (both 6A) as have several friends and all charge/taper correctly (I have plotted the CV/CC curves) on the MSX's, thats why your comment seemed unusual. Maybe it's just that specific variable current one you have.

Link to comment
Share on other sites

8 hours ago, Ben Kim said:

The taper in CV is way too short, also does not trickle charge when it’s “done” charging. Charger just shuts off when it thinks it’s done, which doesn’t give enough time for the batteries to balance.

You know by accident at which current threshold the charger shuts off? Or can this maybe even be adjusted?

~10*50mA=0.5A would be about perfect for the Sherman

8 hours ago, Ben Kim said:

On stock Gotway/Veteran chargers it will continue to balance at 0.1A for up to 24 hours until it’s truly “done”. 

That's imho very bad treatment for the batteries.

Mostly balancing should be done during the CV stage and _after_ charging by the bleeding resistors.

If one such cycle is should not enough for balancing it can be repeated. But very likely the battery pack is in such a case already too aged/degraded and should be replaced.

At least this are my insights after trying some simulation of passive bms as used in EUCs: https://forum.electricunicycle.org/topic/22109-passive-balancing-a-simulation/?tab=comments#comment-359235

Li Ion cells should only be charged downto ~50-60mA according to the manufacturers datasheets. 

Trickle/floating/... charging is _not_ recommended for li ion cells!

8 hours ago, Ben Kim said:

Like I said, given I only use this charger outdoors, I don’t really mind. 

As i see this by now this charger could be very recommendable (depending on shut off threshold)! After long time finally a charger respecting li ion cell charge specifications and not unnecessarily torturing them with trickle charge!

Could also decrease a bit the chance of a fire hazard ...

  • Like 2
Link to comment
Share on other sites

My JR-T450 shuts of entirely, then, as voltage settles a bit, it powers on again. It does this in an endless loop, starting and stopping the current (with the relay) and the fan. I tried leaving it to see if it would stop, but after an hour of cycling (as short as a few seconds toward the end) I gave up.

It does have a potentiometer for setting the cut off voltage, but that wouldn’t change anything for partial charge where it also goes into a loop.

Link to comment
Share on other sites

14 minutes ago, null said:

My JR-T450 shuts of entirely, then, as voltage settles a bit, it powers on again. It does this in an endless loop, starting and stopping the current (with the relay) and the fan.

An very interesting design decission :blink1:

Best to disable this feature!

  • Like 1
Link to comment
Share on other sites

Indeed! I suppose they have revised it since then.. But there is a whole bunch of these (from my research) who does it.. I can’t fathom they conceived them this way.. 

Link to comment
Share on other sites

8 hours ago, Chriull said:

You know by accident at which current threshold the charger shuts off? Or can this maybe even be adjusted?

~10*50mA=0.5A would be about perfect for the Sherman

That's imho very bad treatment for the batteries.

Mostly balancing should be done during the CV stage and _after_ charging by the bleeding resistors.

If one such cycle is should not enough for balancing it can be repeated. But very likely the battery pack is in such a case already too aged/degraded and should be replaced.

At least this are my insights after trying some simulation of passive bms as used in EUCs: https://forum.electricunicycle.org/topic/22109-passive-balancing-a-simulation/?tab=comments#comment-359235

Li Ion cells should only be charged downto ~50-60mA according to the manufacturers datasheets. 

Trickle/floating/... charging is _not_ recommended for li ion cells!

As i see this by now this charger could be very recommendable (depending on shut off threshold)! After long time finally a charger respecting li ion cell charge specifications and not unnecessarily torturing them with trickle charge!

Could also decrease a bit the chance of a fire hazard ...

I actually have an in-line voltmeter (something homemade, similar to a Charge Doctor) to monitor actual current along with the total Wh for any given charge session.  

The typical Gotway/Veteran stock chargers will start tapering current entering CV around 99.5V and will continue to output 0.1 to 0.3A after the light goes green.  It could continue to output this amount for up to 24 hours at which point it is balancing cells (most BMS balance at 50mA (0.05A), so it is not a quick process).

The adjustable 9A charger from pmbatterychargers.com will aggressively taper the current entering CV which looks more like a countdown than a CV.  Once the charger deems it to be done, it shuts off with no balancing, the screen shuts off.  With that said, this charger does not properly balance cells, and would NOT be a suitable home charger replacement.  

Explain how 0.1-0.3A of current is torturing a lithium cell?  If these large battery packs are not subjected to a full CV cycle at all, the cells will never be properly balanced.  The second a charger is pulled, the resting voltage will NOT be 100.8V nor will the cells ever properly balance.  

Personally, I think eWheels is doing newbies a disservice by touting their variant of this charger as some beneficial savior of cycle life without addressing the downfalls of not properly balancing giant 24S packs; given 300 FULL cycles of a typical 1800Wh EUC pack will net roughly 40 miles worst case, someone would have to put 12000 miles on their EUC before they see 20% battery degradation.  Cell aging will get these packs before the number of cycles do.  

My recommendation?  Use the included stock chargers at home, charge them full every time, save these fast chargers for topping off on long rides.  Charging at high speeds constantly will do more to age batteries than charging them full using the comparatively slow stock chargers included with these wheels where all the cells are properly balanced.  

Edited by Ben Kim
  • Like 1
Link to comment
Share on other sites

4 hours ago, Ben Kim said:

Charging at high speeds constantly will do more to age batteries than charging them full using the comparatively slow stock chargers included with these wheels where all the cells are properly balanced.  

_If_ the fast charger doesn’t allow proper balancing yes. Otherwise our “ fast” is the battery specs “normal”.. (my C1200 10A charger does a proper CV all the way)

(I use stock when at home not to heat stuff more than necessary, but ATM I don’t think we have documentation stating slow slow charge make any difference on the batteries)

Edited by null
  • Like 1
Link to comment
Share on other sites

57 minutes ago, Ben Kim said:

Explain how 0.1-0.3A of current is torturing a lithium cell? 

That seems to be common knowledge. Googling for li ion trickle/float charge finds enough sources.

I personally got it from https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

"Li-ion cannot absorb overcharge. When fully charged, the charge current must be cut off. A continuous trickle charge would cause plating of metallic lithium and compromise safety. To minimize stress, keep the lithium-ion battery at the peak cut-off as short as possible."

That's very clear and not to be misunderstood. Feel free to choose your source of trust from the search results.

1 hour ago, Ben Kim said:

If these large battery packs are not subjected to a full CV cycle at all, the cells will never be properly balanced

Cutting off at about 3%C or 50-60 mA per parallel cell (as specified by zhe manufacturer) is a _full_ CV cycle.

That's why i asked you at which threshold this charger cuts off.

You seem to ignore the balancing sulation link i gave in my last post?  Balancing is very likely to work very different to how the community _believes_.

You have any arguments/proof why no balancing should happen or it's just hearsay?

  • Like 1
Link to comment
Share on other sites

do You think it is safe to use this charger in version 2/6/8 Amps wit double pins with Monster v3 ( battery cells Sanyo NCR18650GA )  ? I plan to use 8A NOT for regular home charge, but only occasionally in long travels for partial 60-75 minute charge e.g. from 30% to 80%. 

How to use it fully safe with Monster v3:

1) 8A to 100% battery

2) 8A to 90% battery and later 6A to 100%, 

3) 8A to 80% battery and later 2A to 100% 

I used already 5Amp charger in Msx (this same battery cells like in Monster), also only occasionally for partial charge - no problems at all. But... 8A is more than 5a. 

 

Link to comment
Share on other sites

1 hour ago, Greg X said:

How to use it fully safe with Monster v3:

1) 8A to 100% battery

2) 8A to 90% battery and later 6A to 100%, 

3) 8A to 80% battery and later 2A to 100% 

If 8A are safe for the Monster v3, it's 1(

During the cv stage (very roughly last 5-15%) the current is determined by the difference between (internal) battery voltage and max charger voltage and not the maximum charger current.

Link to comment
Share on other sites

3 hours ago, Ben Kim said:

My recommendation?  Use the included stock chargers at home, charge them full every time, save these fast chargers for topping off on long rides.

Define 'fast chargers' please.

3 hours ago, Ben Kim said:

  Charging at high speeds

Define 'high speeds' please.

And remember to include what cells and in what configuation you are relating to.

3 hours ago, Ben Kim said:

constantly will do more to age batteries than charging them full using the comparatively slow stock chargers included with these wheels where all the cells are properly balanced.  

I'm sorry but thats bollocks. I have deliberately kept out of this conversation after you appeared to slag off all 6A+ chargers but theres a limit I can take.

It appears you have an issue somewhere (I suspect your charger) but do not tarnish all 5A+ chargers the same way.

To put all this into perspective, my bog standard ebike using a Bosch powertrain has a 36v/625Wh battery. It is supplied with a 'standard' 4A charger. The 'fast charger' (by Bosch) is 6A. And being Bosch, I would say they are conservative, catering for the masses with no knowledge of battery conditioning whatsoever.

To suggest that charging at 6A is taxing the sort of batteries we have in big euc's is garbage.

Learn about serial/parallel battery connections, study the manufacturers cell specs then come back to us about what the max rated charging current is.

And no, I'm not including what the wheel/BMS is doing because you have already discounted that.

Link to comment
Share on other sites

as far as i know - Monsters v3 100v have double pins, just like MsP. 

but how to charge it fully safe? 

1) 8A to 100% battery

2) 8A to 90% + 6A to 90-100%, 

3) 8A to 90% + 2A to 90-100%

4) 8A to 80% + 2A to 80-100% 

I assume, 8A to 80% battery should be safe, because battery is empty and takes all voltage, BMS is not under high pressure. 

But 80-100% or 90-100% battery doesnt takes enough voltage, and BMS has to convert excess current into heat. Thats why i dont know, if using in this interval still 8A is still safe, or I should lower charger to 6A or even to 2A?  And when - at 80% or at 90%. 

  • Like 1
Link to comment
Share on other sites

1 hour ago, Greg X said:

but how to charge it fully safe? 

1) 8A to 100% battery

2) 8A to 90% + 6A to 90-100%, 

3) 8A to 90% + 2A to 90-100%

4) 8A to 80% + 2A to 80-100% 

As written above 1). If the wheel takes 8A it does not change anything if you change the charger after 80/90%.

1 hour ago, Greg X said:

I assume, 8A to 80% battery should be safe, because battery is empty and takes all voltage, BMS is not under high pressure. 

The voltage does not cause any pressure that could endanger the BMS. Just as more the battery is empty, the more current can flow. The task of the charger is to reduce the current to some constant maximum safe charging current. As in your case 8A or with stock chargers some 1.5A..3A.

The fliwing current is the value that burdens the bms - power dissipation at the protection mosfets is the square of the current times their resistance. Their resistance turned on is constant (very low) - the charging current is what can be changed.

1 hour ago, Greg X said:

But 80-100% or 90-100% battery doesnt takes enough voltage, and BMS has to convert excess current into heat.

No. Again other way round. There is lower voltage difference and so less current is fliwing - (mostly) far less as the charger could provide. So it makes no sense to change to some 2A or 6A charger.

1 hour ago, Greg X said:

Thats why i dont know, if using in this interval still 8A is still safe, or I should lower charger to 6A or even to 2A?  And when - at 80% or at 90%. 

If you have concerns - the 0-8x% is the important part were a high amp charger could overpower connectors/wires/mosfets or overheat the cells.

  • Like 2
Link to comment
Share on other sites

You're getting too hung up on it. All chargers should drastically reduce current as the balancing phase starts so it makes no odds whether its a 20A charger or a 1A charger. At the end they should all be about the same current anyway.

Edit: Chriull just beat me to it :)

 

Edited by Planemo
  • Like 3
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...