Questions about using different chargers on the KS16X simultaneously

[BKW]

I currently have the stock charger that came with the KS16X, which is the 84V, 2.5A charger. I am looking to add another charger to use simultaneously on the wheel to quicken the charging time. Would it be OK if I used a 84V, 5A charger and a 84V, 2.5 charger at the same time on the 16X?

Ewheels recommends not charging the 16X above 5A at a time, but I've also read the 16X can do 10A safely. Thoughts on this? Any general safety concerns I should be aware of? Thanks

[Chriull]

1 hour ago, bkw said:

Ewheels recommends not charging the 16X above 5A at a time, but I've also read the 16X can do 10A safely. Thoughts on this? 

Afair there were some motherboard versions of ks16x which in combination with some firmware versions stopped charging above some current threshold.

As with some mb version they started to report charging current?

But i don't know how the situation is with the actual firmware.

1 hour ago, bkw said:

Thoughts on this? Any general safety concerns I should be aware of?

Often of 5A per "2 pins" of the GX connectors beeing safe is spoken. So this should work out?

Still the input protection circuitry of the BMS is the big unkown - there is (mostly just) one MosFet without heatsink under the plastic wrap. With a Rdson of some 5 mOhm and 10A he dissipates 0.5W - could work out if the pcb is nicely designed or just be too much ...

Best to watch this closely at the first charging attempts - best at worst case conditions: highest ambient temperatures you're ever going to charge and "prewarmed" batteries.

[Tazarinho]

I seem to remember it's the wires that can't handle the load and the manufacturer does not recommend charging more than 6A.I have an original charger as well as a 5A but have never used them together, nor do I want to, I just wait for the extra half hour on the 5A. I seem to remember there was a German rider who frequently charged 9A on road trips though. 

In my opinion you can occasionally combine the two chargers, especially if really needed, but there's always a risk and I wouldn't make a regular habit out of it.

[supercurio]

Aside from on older firmwares, the mainboard will beep when charging beyond ~5.5A. Although the limit is supposed to be 6A, the charging current reading is noisy which makes it beep at lower actual current.

@EUC Custom Power-Pads was charging his 16X way faster than 6A (9 or 10A?) without issue after adding a switch to disconnect the beeper on demand for some time, but then switched to an MSP so his experience can't be extrapolated to doing so long term.

[RayRay]

Try this to charge much faster... (1.21 GW)

Spoiler

 

Edited March 15, 2022 by RayRay
spoiler

[BKW]

These are very insightful posts. Thanks for that! I don't want to experiment and push anything, so if the limit is supposedly 6A, I'll just stick to a 5A charger at most.

[Tawpie]

I charge my 16X with two chargers that total 5.5A... an eWheels 'fast' charger set to 4A and 80% plus the stock 1.5A slow charger (my wheel started life as an XS so it came with a brutally slow charger). So far so good, no beeping and no indication of overheated wiring.

What's nice about that is the eWheels fast charger shuts down at 80% and the 1.5A slow charger finishes charge and balance. Once it hits the CV point (at about 80% SOC), I don't need the extra current and noise of the fast charger.

[AndyBill]

Hello I am a newbie and a proud owner of a King Song 16x. So reading through this thread it looks like it is safe to charge the 16x at 5A with the fast charger? I was intending on only charging to 80% at 5A to hopefully get the maximum battery life. Thank you in advance and sorry if it’s a dumb question.

[Chriull]

1 hour ago, AndyBill said:

I was intending on only charging to 80% at 5A to hopefully get the maximum battery life. Thank you in advance and sorry if it’s a dumb question.

Unfirtionately that's a way to destroy the battery ;(

There are many duscissions about this topic already - one can google for

site:forum.electricunicycle.org 80% charging

Here one video about this topic:

Edit: deleted "the fastest way" as there are many other ways to destroy li ion batteries faster...

Edited March 24, 2022 by Chriull

[meepmeepmayer]

To be clear:

• Too many Amperes would mean more than the charge port (weakest link) can handle, but 5A is totally fine and way below any threshold.
• The charging get slower towards the end anyways, so Amperage matters even less. A 5A charger is totally fine for charging to 100% or any other percentage. Charging with a 5A charger is not bad for the battery in any way.
• You should regularly charge to 100% (and keep the charger in for a few hours after it goes green) to fully charge your battery. If you never charge your battery fully, it will age unevenly and may fail early. That is what @Chriullmeans.

That's all. Hoping this clears up any confusion

[AndyBill]

Wow, thank you so much for this information. The video was very helpful as well. I'm glad that I checked here rather than relying on the info from eWheels. Just be sure, the Lenovo charge port can handle up to 5A?

[meepmeepmayer]

1 minute ago, AndyBill said:

Just be sure, the Lenovo charge port can handle up to 5A?

Yes, easily.

[supercurio]

I'm not sure there's an official spec for these Lenovo connectors (real ones or copies) but we can say confidently enough that they prove many times their capability of handling this kind of current.

 

[AndyBill]

Thank you so much. One last question that I'm almost embarrassed to ask, but should the EUC be powered off when charging? I see a red light on the top of the EUC that is on while charging so I suppose that means the unit is in a standby mode even though it is powered off. I have so much to learn and I really appreciate the knowledgable and helpful replies.

[.....]

57 minutes ago, AndyBill said:

Thank you so much. One last question that I'm almost embarrassed to ask, but should the EUC be powered off when charging? I see a red light on the top of the EUC that is on while charging so I suppose that means the unit is in a standby mode even though it is powered off. I have so much to learn and I really appreciate the knowledgable and helpful replies.

Power it off while charging. Tho I hear the KS wheel is capable of being charged while riding, via modular battery pack. For 99.9% of us, we don't do that and we charge when stopped. Tho you COULD charge it while powered on and self balancing, why would you? Yes, the KS wheels (when off) kind of go to a 'standby mode' while charging. You can easily hear when it goes off 'standby'.

Basically, turn wheel off, plug in charger to the wall, plug charger to wheel. Wait until light goes green, unplug wheel, unplug charger from wall. Every now and then you may wait a couple hours after lights go green, but I am not convinced its doing anything, as you can HEAR the wheel fully power down and the charger doesnt seem to be putting out any kind of voltage. My ewheels chargers show its not doing a damn thing once it hits 100% and the wheel goes fully off.

Edited March 25, 2022 by ShanesPlanet

[AndyBill]

I charged the wheel fully last night using the eWheels style fast charger. I set the charger to 3A, 100%. The charger reached a full 84 point something volts and the charger light turned green. I checked the voltage with DarknessBot in the morning after the wheel sat overnight and the app said something like 82.4 volts. Would this be considered normal? 

One other thing I noticed was that even though the charger was set to 3A amps, while charging DarknessBot was only showing about 1.5A charging rate which doesn't seem right. The wheel was at 30% roughly before I started charging and took about 5 1/2 hours to fully charge. (This is a brand new wheel, BTW).

Thank you for the information and feedback!

[Paradox]

2 minutes ago, AndyBill said:

The charger reached a full 84 point something volts and the charger light turned green.

On my 18XL and My 18L they both charge to 84.5v.  Do you have the stock charger?  I use two stock chargers.  I am not sure the fast charger will allow balancing?

[AndyBill]

Yes, I do have the stock charger. That’s a good thought though. I’ll try the stock charger next time because I don’t think the eWheels charger was letting it balance. It just shut off as soon as the peak voltage was reached.

I will try using both chargers at the same time like Tawpie does. As long as the combined charging amps are below 5A I should be good to go? The stock charger will take over and trickle charge once the top voltage is reached.

Edited March 25, 2022 by AndyBill
Reword

[meepmeepmayer]

1 hour ago, AndyBill said:

I checked the voltage with DarknessBot in the morning after the wheel sat overnight and the app said something like 82.4 volts. Would this be considered normal? 

It's a bit low. The fast charger might be a little weak and not charge to the full 84V?

Or maybe Darknessbot shows false numbers?

Voltage readous are notoriously imprecise, that might be all there is to it, too.

Occasionally new wheels used to need a few charges until they charged to full voltage, that might be it, too.

Try your regular stock charger (only) and see what happens.

In general, things like this are almost always a charger issue and not something with the wheel.

1 hour ago, AndyBill said:

DarknessBot was only showing about 1.5A charging rate which doesn't seem right

When did it show that? Towards the end of the charging process, the current goes down to zero, so you might have caught it in that in-between phase.

21 minutes ago, AndyBill said:

I’ll try the stock charger next time because I don’t think the eWheels charger was letting it balance.

Balancing is charger-independent. The BMS (battery management system) of your battery packs does the balancing, but (for some equally dumb and inexplicable reason) it only happens when the battery is full enough, e.g. above a certain voltage. So all you need to care about is that you often enough reach that voltage (that's behind the "charge to 100% regularly" recommendation).

Edited March 25, 2022 by meepmeepmayer

[Paradox]

4 minutes ago, AndyBill said:

I will try using both chargers at the same time like Tawpie does. As long as the combined charging amps are below 5A I should be good to go? The stock charger will take over and trickle charge once the top voltage is reached.

If your battery is low the fast charger will charge at a high level.  Combine this with a stock charger might put you over the limit.  Using the stock charger toward the end of charging might be ok since the fast charger is charging at a lover level.  This is my guess since I have not tried a fast charger with the stock charger.

[Paradox]

Note that the stock charger will take a long time by itself.  The two stock chargers I have are 1.5 amp but I think newer stock chargers might be higher amps.

[meepmeepmayer]

22 minutes ago, AndyBill said:

I will try using both chargers at the same time like Tawpie does. As long as the combined charging amps are below 5A I should be good to go? The stock charger will take over and trickle charge once the top voltage is reached.

I'm not knowledgable about this kind of stuff, but using two of something in parallel always entails the risk that one of them brings the other down. E.g. the stock charger stops because the other one did. I don't know if that can happen (charging logic).

So, I would try the stock charger alone first, to see what is up. 84V or not? Then, you can do 2 chargers and whatnot.

Edited March 25, 2022 by meepmeepmayer

[Paradox]

Just now, meepmeepmayer said:

I'm not knowledgable about this kind of stuff, but using two of something always entails the risk that one of them brings the other down. E.g. the stock charger stops because the other one did. I don't know if that can happen.

When I use the two stock chargers one will stop charging and the second will continue near the end of charging.  I have both plugged into two different energy monitoring smart switches so I can see what is happening.

[AndyBill]

23 minutes ago, meepmeepmayer said:

 

When did it show that? Towards the end of the charging process, the current goes down to zero, so you might have caught it in that in-between phase.

 

The app showed the low charging amps pretty early on in the charging cycle, not towards the end. My fast charger was showing about 3A and the app was showing around 1.5A give or take. The amperage on the fast charger did slowly reduce the last half hour or so.

I’m not real worried about it but just curious. 
 

I will try charging just with the stock charger. Kind of feel like I wasted my money on the fast charger.

Edited March 25, 2022 by AndyBill
Reword

[Paradox]

Just now, AndyBill said:

I will try charging just with the stock charger. Kind of feel like I wasted my money on the fast charger.

I think fast chargers are good for going from a low battery up to about 80%.