Fast charging the Kingsong 16X

[mrelwood]

On 8/11/2019 at 9:10 PM, chrisjunlee said:

11.5 A @20V implies ~2.7 A at 84V right?

For power, yes, but connectors (, switches and cables etc) specify a max amp rating besides the max voltage rating. They don’t tend to specify a max power rating. If it can take 11.5A at 20V, it should be able to handle 11.5A at the maximum specified voltage as well. 

[ir_fuel]

On 8/6/2019 at 7:52 PM, eddiemoy said:

the KS new wheels with the dual lenovo connectors can charge at total of 10A, 5 for each port.  

Just got a mail telling me the KS16X can only do 5A max because of the internal wiring.

[eddiemoy]

6 hours ago, ir_fuel said:

Just got a mail telling me the KS16X can only do 5A max because of the internal wiring.

From who?

[ir_fuel]

10 hours ago, eddiemoy said:

From who?

1radwerkstatt, when asking for a bigger fast charger. They are the official KingSong distributor in Germany.

[eddiemoy]

43 minutes ago, ir_fuel said:

1radwerkstatt, when asking for a bigger fast charger. They are the official KingSong distributor in Germany.

Is it limit of 5a per port or total?  Doesn’t make much sense if it is total. I’ve see. Folks use both the fast charger and the stock charger together for over 5a. 

[ir_fuel]

2 minutes ago, eddiemoy said:

Is it limit of 5a per port or total?  Doesn’t make much sense if it is total. I’ve see. Folks use both the fast charger and the stock charger together for over 5a. 

Total.

As I said in a different topic, I suppose there is the "official" limit and then there is the limit of what it will actually support without breaking down.

[eddiemoy]

1 minute ago, ir_fuel said:

Total.

As I said in a different topic, I suppose there is the "official" limit and then there is the limit of what it will actually support without breaking down.

Question is what are you claiming or what is the distributor claiming.  I know most even hard core OG EUC riders are reluctant to charge at higher rates because they fear a fire.   I’ve done the math and it seems that even at 10A, it isn’t all that much current per cell.   You don’t even need more than a 20G wire.  To the packs is 1.6a, you can use a 27G wire.  That is thin!

[US69]

I just have a official Question open at KS Headquarters.

On earlier wheels, before double connector, it was 5 Amps total, but as now two ports go to board and from there to 2 battery packs i would suspect a 10 Amp total, as even with 10Amps on no wire is more than 5 Amps. Means 5 Amps max PER charge port.

But as said, i wait for an official anwer!!!

Edited August 19, 2019 by US69

[ir_fuel]

4 minutes ago, eddiemoy said:

Question is what are you claiming or what is the distributor claiming.

I'm claiming nothing. I'm just saying what the distributor told me.

4 minutes ago, eddiemoy said:

 I know most even hard core OG EUC riders are reluctant to charge at higher rates because they fear a fire.   I’ve done the math and it seems that even at 10A, it isn’t all that much current per cell.   You don’t even need more than a 20G wire.  To the packs is 1.6a, you can use a 27G wire.  That is thin!

Cell current is never the issue, it's the wiring on the connectors and to the batteries, if I recall correctly.

But as I said, I don't know, I just relay what official sources tell me. And for me a distributor is an official source.

4 minutes ago, US69 said:

I just have a official Question open at KS Headquarters.

On earlier wheels, before double connector, it was 5 Amps total, but as now two ports go to board and from there to 2 battery packs i would suspect a 10 Amp total, as even with 10Amps on no wire is more than 5 Amps. Means 5 Amps max PER charge port.

But as said, i wait for an official anwer!!!

I asked 1radwerkstatt to build me a 10A charger with 2 parallel plugs so I have 5A per plug. A charger on which I can reduce current to 8A to be safe. They simply refused as they claim 5A is the max the KS16X can handle. That's my info on the topic so far.

[US69]

2 minutes ago, US69 said:

I just have a official Question open at KS Headquarters.

On earlier wheels, before double connector, it was 5 Amps total, but as now two ports go to board and from there to 2 battery packs i would suspect a 10 Amp total, as even with 10Amps on no wire is more than 5 Amps. Means 5 Amps max PER charge port.

But as said, i wait for an official anwer!!!

And even as it is allready 11pm in China i got the answer.

 

KS engeneers/tech Support says it is 5 Amps PER charge port, so 2 x 5 Amps Total. 

As theoretical value!!!

 

Nonetheless:

I would personnaly NOT charge with higher than Total 6 Amps...that is 1 Amp per one seriell battery block/cell

[ir_fuel]

1 minute ago, US69 said:

And even as it is allready 11pm in China i got the answer.

 

KS engeneers/tech Support says it is 5 Amps PER charge port, so 2 x 5 Amps Total. 

As theoretical value!!!

 

Nonetheless:

I would personnaly NOT charge with higher than Total 6 Amps...that is 1 Amp per one seriell battery block/cell

Please send this info to 1radwerkstatt so they can make me a charger :p 

[ir_fuel]

6A = 1A per serial pack.

1554Wh / 6 = 259Wh per serial pack

at 84V that amounts to 3.08Ah per serial pack

1C on that pack = 3A. So pushing 1A in 1 serial pack = 0.34C.

10A = 1.67A per serial pack = 0.55C

IMO that's still pretty safe, considering all the wiring supports it.

 

[US69]

Just now, ir_fuel said:

Please send this info to 1radwerkstatt so they can make me a charger :p 

As i said above...i also would not recommend more than 5/6 Amps....and normally Chris absolutly knows what he's Talking about.

Nonetheless , he sure also just wants to be carefull!

 

10 Amps are 800Watt...which is a lot, especially continuos flowing..

[ir_fuel]

Just now, US69 said:

As i said above...i also would not recommend more than 5/6 Amps....and normally Chris absolutly knows what he's Talking about.

Nonetheless , he sure also just wants to be carefull!

 

10 Amps are 800Watt...which is a lot, especially continuos flowing..

I know. The problem is: you either get a 5A  or a 10A charger. You can't get a 6 or 7 ... 

So I'd rather get a 10A charger that I can regulate back to 6A or 8A. Otherwise I would need multiple chargers in parallel, and I don't like the idea of using a 5A fast charger + a 1.5a normal one at the same time. I don't see how they switch CC/CV simultaneously.

I have a 1200W charger sitting on my desk, for my LiPos. Makes quite some noise, lol  

[US69]

Just now, ir_fuel said:

6A = 1A per serial pack.

1554Wh / 6 = 259Wh per serial pack

at 84V that amounts to 3.08Ah per serial pack

1C on that pack = 3A. So pushing 1A in 1 serial pack = 0.34C.

10A = 1.67A per serial pack = 0.55C

IMO that's still pretty safe, considering all the wiring supports it.

 

On Little mistake ...you would Need to divide the 259whs by 74Volt.

But you can have it easier:

One cell is 3500mah '= 3,5Ah

1C = 3,5

0,5 C = 1,75Amp...

So yes, it is even under 0,5 C

 

Still....from my vaping experience with 18650...Charging them with more than one Amp brings down the Lifetime significantly.

 

But in the end everyone must decide that for his own.

[US69]

1 minute ago, ir_fuel said:

I know. The problem is: you either get a 5A  or a 10A charger. You can't get a 6 or 7 ... 

So I'd rather get a 10A charger that I can regulate back to 6A or 8A. Otherwise I would need multiple chargers in parallel, and I don't like the idea of using a 5A fast charger + a 1.5a normal one at the same time. I don't see how they switch CC/CV simultaneously.

Dont ask me how….but it works...have done that several times on all my 18S...controlled by chargedoctor.

When going under 1Amp load, mostly one of the chargers (the fast one) stops charging at all and lets that to the smaller one.

[ir_fuel]

Ah the charge doctor. That device nobody can buy anymore it seems  

[US69]

1 minute ago, ir_fuel said:

Ah the charge doctor. That device nobody can buy anymore it seems  

Yeah, thats a real shame!!!

I only have one left….that now goes for all my wheels 67V/84V...several Adapters needed.

[Yellowman]

On 8/6/2019 at 10:52 AM, eddiemoy said:

the KS new wheels with the dual lenovo connectors can charge at total of 10A, 5 for each port.  

Where can I learn more about that charger? Where can I buy it from?

[eddiemoy]

3 minutes ago, Yellowman said:

Where can I learn more about that charger? Where can I buy it from?

fast charger should have came with your order if you bought it from ewheels.

[photorph]

16 minutes ago, eddiemoy said:

fast charger should have came with your order if you bought it from ewheels.

For repeat customers, in most cases.  

Edited October 15, 2019 by photorph

[Seba]

Let's assume that KS-16X uses Samsung 35E cells. Overall battery configuration is 6P20S. According to a cell datasheet, standard charge is specified at 1.7 A but... Samsung states that to keep specified cycle life, charging current should not exceed 1.02 A. So charging current up to 6 A is considered fully safe and not impacting specified battery life and 10 A is still considered fully safe, however will reduce battery life somehow. Any current above 12 A may cause battery to fail.

Of course, it's always wise to charge battery with current as low as possible. As some of you know, I love long-distance riding. It would not be possible without really fast charger - in my case it's a 10 A charger that I carry in my backpack. So when I'm on tour I charge with currents at about 8-9 A to save time. But for overnight charging, I use much smaller currents.

[photorph]

To Update this thread: PLEASE SEE ADVISORY EWHEELS SENT OUT.  .  

[Vida Wang]

On 8/7/2019 at 3:25 AM, chrisjunlee said:

So if I understand this correctly, the current would be distributed over 6 parallel. Or 1.7 A . That's a fast charge value I'm willing to accept. 

For those reading that don't have much experience with 18650 batteries, it's easy to reduce these discussions to black and white thinking, which become dogma without context.

FWIW, these are the conditions I would personally use, given the tradeoffs I've chosen:

• slow charging: 1.5 A stock charger (1.5A / 6 = 0.25 A per cell. Incidentally, this is precisely the lowest most 18650 chargers go to)
  • use case: overnight, I don't need the wheel for the next 12+ hours
• regular charging: 5.0 A rapid charger (5.0A / 6 = 0.83 A per cell, which is below the 1.0 A regular charging threshold)
  • use case: topping off at work, daily commuting 
• fast charging: 10.0 A or two rapid chargers (10/6 = 1.67 A per cell. 2.0 A is considered fast, so 1.67 is a bit under that)
  • use case: those rare summer days when you need to charge between long epic rides

For posterity, the tradeoff is overall battery cycle life. The lower you stress the cells, the longer they last. But, charging is just one aspect of that: discharge rate is something I never see being discussed. What good is it to baby your batteries with a 0.25 A charge load, when you're ripping uphill pulling 10 A per cell?

Again, this is my just perspective, with the values and use cases I've chosen. I believe it is a reasonable set of choices to maximize your riding time, and thus your utility/enjoyment of your wheels.

I agree with your opinion.
Prepare different chargers for different purposes is the best way to use it.

[Garrie Lim]

On 10/23/2019 at 1:37 AM, Vida Wang said:

I agree with your opinion.
Prepare different chargers for different purposes is the best way to use it.

I wrote about this topic many times in this forum. 
 

 

5A isn’t fast charging, even 10A isn’t fast charging when it comes to most 20S6P wheels. 

On 10/16/2019 at 2:22 AM, Seba said:

Let's assume that KS-16X uses Samsung 35E cells. Overall battery configuration is 6P20S. According to a cell datasheet, standard charge is specified at 1.7 A but... Samsung states that to keep specified cycle life, charging current should not exceed 1.02 A. So charging current up to 6 A is considered fully safe and not impacting specified battery life and 10 A is still considered fully safe, however will reduce battery life somehow. Any current above 12 A may cause battery to fail.

Of course, it's always wise to charge battery with current as low as possible. As some of you know, I love long-distance riding. It would not be possible without really fast charger - in my case it's a 10 A charger that I carry in my backpack. So when I'm on tour I charge with currents at about 8-9 A to save time. But for overnight charging, I use much smaller currents.

16X uses LG MJ1 cells I think