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

[WI_Hedgehog]

23 hours ago, Declan acoustic-unicyclist said:

These are just YZpower chargers from Aliexpress. It literally says right on the label.

I'm not seeing YZ Power chargers as having adjustable amperage / termination voltage / displays. Are these add-on features by PMBattery?

 

22 hours ago, Planemo said:

I don't think PMBattery make any secrecy about the fact they are YZ. I wouldn't be surprised if they are both affiliated in some way. In any event YZ are well known for chargers.

I've had 3 myself now, and 3 other guys I ride with have also purchased them. Zero problems

Thank you! I see PMBattery has YZPower's logo right in PMBattery's page logo area.

[ray rokni]

here is the direct link to their site. remember this is for 100.8 gw wheels

https://www.pmbatterychargers.com/900W-842V-6A-8A-10A-current-adjustable-digital-display-partial-charge-lithium-li-ion-battery-charger-for-84V-gotway-free-shipping-p2718646.html

 

[xorbe]

On 5/3/2020 at 11:09 PM, ray rokni said:

here is the direct link to their site. remember this is for 100.8 gw wheels

[... wrong link ...]

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 30^th: order placed

June 16^th: order sent via DHL

June 18^th: order received

Edited June 19, 2020 by xorbe

[xorbe]

What I got, and is now shown on the product page: (when I ordered, it was a generic image) and slightly different than the first post of this thread:

I only really plan to use the 5A charging, though I have the option to use more if I'm in a rush for some reason some day.

EDIT: Well, the regular ordering page is back up, beats me!  (It was disabled when I posted this earlier.)  "USA Plug #2, with GX-16 5 pin 1+ 2+ and 4- 5-"

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

Edited June 19, 2020 by xorbe

[Planemo]

Hmm a bit cheeky not getting the same meter as advertised, given is does provide some additional handy data.

It would also be better if they used a 4 digit voltmeter, although I must admit I really struggled to find one when I was trying ro retrofit a meter to my basic PM charger. Most are under 100v but I did find one in the end albeit I would have preferred the type with more data.

 

Edited March 4, 2022 by Planemo

[Planemo]

Had a PM asking where I found a 4 digit meter, thought I would post it here for reference:

https://www.ebay.co.uk/itm/333608518165

[EMA]

arrived mine yesterday, some pics and weight

 

[xiiijojjo]

Would I be able to charge a gotway rs with the default 3a charger + this 8a charger in the 2nd port? 

Edit: Speedyfeet's review says it's rated for 20a. I wonder if that means each port can take 10a along with all components leading the the battery which then takes all 20a

Edited October 25, 2020 by xiiijojjo

[Bongaloid]

On 10/25/2020 at 12:52 PM, xiiijojjo said:

Would I be able to charge a gotway rs with the default 3a charger + this 8a charger in the 2nd port? 

Edit: Speedyfeet's review says it's rated for 20a. I wonder if that means each port can take 10a along with all components leading the the battery which then takes all 20a

Someone should please correct me if I'm wrong but I'm pretty sure I read somewhere that this wheel should not be charged with more than 8A at a time.

[EMA]

On 10/25/2020 at 8:52 PM, xiiijojjo said:

Would I be able to charge a gotway rs with the default 3a charger + this 8a charger in the 2nd port? 

on 1800wh battery you are in the "standard charge" up to 6A, going up to 8 it's possible but not recommended for a lot of reasons, specially if you care about your battery (aka your wheel)

[xiiijojjo]

15 hours ago, EMA said:

on 1800wh battery you are in the "standard charge" up to 6A, going up to 8 it's possible but not recommended for a lot of reasons, specially if you care about your battery (aka your wheel)

I'd love to know how exactly battery size relates to safe charging amperage. Up until now I always figured that the safe charging amperage related to the specific li-ion cell's limits and in which configuration the battery is assembled (how many cells in series and parallel) and as such I didn't figure that you could determine safe charging amperage from simply knowing the battery size. 

I'd like to know how these 6a and 8a values are determined. I need to learn more about safe charging 

[EMA]

you can find the LG M50T datasheet online with alla the info you need: https://www.batteryspace.com/prod-specs/11514.pdf

standard charge is 0.3C

1800wh / 100v = 18amp (approx)

0.3C on a 18a battery is 6a

[null]

Edit: I was a bit quick and did my eyeballing based on 84v and less. To get the size of a battery in Ah you can use this calculator (V*Ah=Wh) For higher voltage batteries we get fewer Ah per Wh than with lower voltage.

edit 2: As @xiiijojjo found, 21700 cells (at least the LG) don’t seem to have the same charge rate, with only 0.3C as recommended (to confirm?)

So while my affirmations bellow mostly holds, especially with 18650 cells and lower voltages, the RS (and most 21700 EUCs?) might not take as fast charge as I had thought.

——

Up to 0.5C is within most batteries healthy charge speed, hence about 2h for 100%. Many wheels don’t even take that amperage at the charge port, I doubt 8A for a 1800Wh is reaching 0.5A. The 1550Wh 18XL officially takes 10A which is a hair over 0.5C (Edit: as a 84V EUC the battery is 18.5Ah)

This article goes into detail from a EUC perspective. Even a 840Wh 16S can charge at 6.25A (Edit: 67V makes it 12.5Ah battery)

At the battery size we’re looking at the charge port, wiring and eventual logic board will be the bottle neck before the battery takes any particular wear. Fast riding will probably pull harder than the charge we’re able to. (Paragraph validity depends of battery size and cell spec, the point about discharge rate holds though)

Regarding the RS in particular I don’t know what the limit is, however the 8A limit @Bongaloid mentioned is probably recommended upper limit of the GX16-5 with 4 pins used. It can take 10A but apparently gets quite hot, hence 8A. Same for the Sherman. Having two charge ports the RS most probably can take 10A total. (Edit: this might be wrong if the 21700 LG cell does indeed have a limit of 0.3C)

edit: and yes @xiiijojjo we should be using the battery amperage. Edit: I dug up a calculator, it does make a difference with the voltages.

Edited November 3, 2020 by null

[xiiijojjo]

From the LG M50T sheet I can clearly see the 0.3C recommendation 

And from the other article about 18650 cells the recommended charge current is 0.5C 

I'm just surprised that the difference is so big when people on this forum keep comparing these cells more or less 1:1... I always thought 21700 and 18650 was more or less same performance but seemingly not when it comes to charging the cells what a shame. 

So I guess I'll have to err on the side of caution for now and use the puny, pathetic 3a default charger 

[null]

@xiiijojjo Indeed, that’s too bad. 1800Wh as 100V would be 18Ah (AFAIK) x 0.3C = 5.4Ah only. Sounds suspiciously low.. 

I’ll correct my write up to include voltage and cell differences.

edit: calculator 

edit 2: The trick was that you need to use nominal voltage for the calculation, so 6A normal charge for the RS.

Edited May 18, 2021 by null

[xiiijojjo]

great work @EMA and @null i ordered the 8a charger weeks ago but i won't use it until our conclusion is proven wrong, which i hope might happen.

Any other users here with LG M50T cells in their wheels + an aftermarket charger ? or did y'all just get chargers with adjustable voltage and amperage to get the 5.4A's of safe charging?

[meepmeepmayer]

0.3 charge cycles/hour * 5000mAh = 1.5A during the charge cycle.

For 4p (1800Wh) that's 4*1.5A = 6A charging.

(Don't expect me to know what I'm computing, but that's how I would do it.)

Copying your calculation, assuming 5000mAh and 3.7V, the exact number is 24*4*3.7V*5Ah/100.8V = 1776Wh/100.8V = 17.62Ah, times 0.3/h that's 5.29A. Taking the even more exact 3.63V from the data sheet instead, you get 5.19A. Not sure why these numbers aren't the same as 6A and which one to use.

Good luck I guess

-

0.3C seems awfully low, but it is how it is. Maybe build a little heater box for your battery, then you get 0.7C at >25°C which gets you 14A charging Which just means (to my very uninformed self) we shouldn't take those numbers too seriously. The battery behavior doesn't suddenly jump from "0.3 is good" to "0.7 is good", does it? Or maybe it does, I wouldn't know.

[KiwiMark]

6 hours ago, null said:

@xiiijojjo Indeed, that’s too bad. 1800Wh as 100V would be 18Ah (AFAIK) x 0.3C = 5.4Ah only. Sounds suspiciously low.. 

I’ll correct my write up to include voltage and cell differences.

edit: calculator 

I suspect that the 1800Wh battery is around 20Ah because despite charging to 100V it isn't actually a 100V battery pack (cells charge to 4.2V, but nominal voltage is actaully 3.7V)  I'd assume a pack with 24 cells in series to give 88.8V nominal and charge to 100.8V.  1800Wh divided by 88.8V gives ~20Ah.  Charging at 0.5C would mean around 10A and I doubt that a 10A charge rate would hurt those cells.  8A would be 0.4C and I've seen an 8A charger listed that is supposed to be suitable for MSP/RS/etc.

[EMA]

7 hours ago, xiiijojjo said:

great work @EMA and @null i ordered the 8a charger weeks ago but i won't use it until our conclusion is proven wrong, which i hope might happen.

Any other users here with LG M50T cells in their wheels + an aftermarket charger ? or did y'all just get chargers with adjustable voltage and amperage to get the 5.4A's of safe charging?

you can charge your wheels with no problems  the charging port will take 8A with no problem.

Just use the 8A when you need a burst outside the house, slow charging is always better for battery life

[null]

7 hours ago, KiwiMark said:

despite charging to 100V it isn't actually a 100V battery pack (cells charge to 4.2V, but nominal voltage is actaully 3.7V) 

Good thing it’s the nominal voltage that counts then, we get more Ah and charge speed. Then my original post is right again except for the 21700 cells only being 0.3C (and as @meepmeepmayer mentioned it probably doesn’t go straight from 0.3 to 0.7)

@EMA I’d be interested if you had a source that indicated that slower than rated standard speed was better for the battery. The whole point of our calculations was to find what standard speed was, to keep out of fast speed. I’m not saying you are wrong, just haven’t seen such a claim confirmed before.

Edited November 4, 2020 by null

[EMA]

4 hours ago, null said:

@EMA I’d be interested if you had a source that indicated that slower than rated standard speed was better for the battery. The whole point of our calculations was to find what standard speed was, to keep out of fast speed. I’m not saying you are wrong, just haven’t seen such a claim confirmed before.

going lower than standard speed 6a is pretty useless, 3-4 or 5a it's basically the same but the slower charge is always better.

What i advice is do not use 8a is you are not in a hurry, better to use the stock 3a charge at home and use the "fast 8a" only when needed.

you can find some general information here, keep in mind we are not in the ultra fast area, we barely reach 0.5C on our huge batteries;)
https://batteryuniversity.com/learn/article/ultra_fast_chargers

Edited November 4, 2020 by EMA

[null]

15 minutes ago, EMA said:

the slower charge is always better

You are stating this without backing why one should go slower that rated standard charge. Your link mentioning moderate is regarding fast and ultrafast charging. The charge rated we are talking about are not even in fast territory.

I give up, no point repeating one selves.

Edited November 4, 2020 by null

[EMA]

6 minutes ago, null said:

You are stating this without backing why one should go slower that rated standard charge. Your link mentioning moderate is regarding fast and ultrafast charging. The charge rated we are talking about are not even in fast territory.

I give up, no point in talking if you are just going to repeat baseless statements.

sorry man, i think i was pretty clear: 

23 minutes ago, EMA said:

going lower than standard speed 6a is pretty useless

and again charging at 3 is better than charge at 8 for your battery life, no one will tell you the opposite, it's a simple advice, you can find lot of information on the web like this:

https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries

"Lower charge voltages prolong battery life and electric vehicles and satellites take advantage of this. Similar provisions could also be made for consumer devices, but these are seldom offered; planned obsolescence takes care of this."

 

sorry for the misunderstanding

[Chriull]

17 hours ago, EMA said:

and again charging at 3 is better than charge at 8 for your battery life, no one will tell you the opposite, it's a simple advice, you can find lot of information on the web like this:

https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries

"Lower charge voltages prolong battery life and electric vehicles and satellites take advantage of this. Similar provisions could also be made for consumer devices, but these are seldom offered; planned obsolescence takes care of this."

Slow, standard and fast charging is determined by the charging current.

The in batteryuniversity mentioned lower charge voltage is some different topic.

I have not found till now an article at batteryuniversity which discusses differences of very very slow, very slow, slow and standard charging ...

Edit: Addentum/more detailed answer:

Afair at batteryuniversity are statements/articles comparing slow/standard/fast and ultrafast charging. Standard charging means charging with 1C, fast above, slow below this number.

Most cells used in actual EUCs have a specified charging rate of 0.5C.

For most of these cells the capacity rating is given for charging and discharging with ~0.2C.

So there "could be something" with lower charge currents increasing lifespans. But that's an unfounded gut feeling.

Imho the 0.2C are choosen by the manufacturer to get great numbers for marketing.

Regarding the increase of lifespan by charging to lower voltages:

 

 

 

Edited November 5, 2020 by Chriull

[Planemo]

Just an update to this. On opening the charger it seemed very much like the 6A was obtained by simply using 2x 3A boards. A quick switch fitted into the parallel line that feeds the second board and bingo, a switchable 3A/6A charger, confirmed by my retro fitted onboard meter. Not sure how much I will use 3A tbh, but its nice to have a slow overnight charge option. Sum cost of £1.59 for a switch and a bit of my time.