Leaperkim Lynx 2700wh: 151V, 20" tire, suspension, 89lb

[EUC Custom Power-Pads]

5 hours ago, onkeldanuel said:

No, done nothing, stock one yes...

But it charges fine. Stops charging at 151,7 like yours, 4,22 highest cell but i want it some bit lower like 4,19 or something 

I only think to remember, that on this "active chargers" like this one and the s22 one you cant measure the output voltage in an unloaded/inaktive state....

That's what I think.

49 minutes ago, Chriull said:

 

You should get a new charger as soon as possible and dispose this 170V charger! This is not the way how li ion batteries are to be charged. With good luck it is only wrongfully assembled to some higher voltage and no further faults come up with this charger.

@EUC Custom Power-Pads is right that the voltage will go down to "normal" values with the battery attached. But the charging will only be stopped by the bms once the first single cell reaches the overvoltage threshold. This threshold is a safety measure which normally with a balanced battery should never be reached!

 

3 years ago I had a adjustable 100.8 V charger with the same behavior, but it was all fine, used it 3 years without problems. The voltage I measured with a voltmeter was above 100.8 v without a battery connected. 

[Chriull]

12 minutes ago, EUC Custom Power-Pads said:

3 years ago I had a adjustable 100.8 V charger with the same behavior, but it was all fine, used it 3 years without problems. The voltage I measured with a voltmeter was above 100.8 v without a battery connected. 

Of course it can go fine. But it's not the way how li ion cells should be charged. Manufacturers and research suggest to charge like described in https://batteryuniversity.com/article/bu-409-charging-lithium-ion. 

[Rawnei]

54 minutes ago, Patrick Robert said:

1812 km on my Lynx (batch 1) already. In all that distance, not a *single* cutout or balanced charge under 151.1V. Sometimes I even hit 151.2V.
I must be doing something right.

So you're taking credit for the charger leaving the factory with correct voltage tuning now are you? 🤣

[Patrick Robert]

38 minutes ago, Rawnei said:

factory

and eWheels 😁🤙

[t0me]

I'd be inclined to be checking voltages on other things to get some idea of whether or not my voltmeter was accurate if I was getting 170v from my Lynx charger.

I adjusted output to 151.3 the just finely down till it just hit 151.2.   My voltmeter's resolution is 1 decimal point.
Dunno if I needed to bother as the BMS seems to do a decent job of adjusting down to what the battery needs and no more.

[Rawnei]

2 hours ago, t0me said:

I'd be inclined to be checking voltages on other things to get some idea of whether or not my voltmeter was accurate if I was getting 170v from my Lynx charger.

I adjusted output to 151.3 the just finely down till it just hit 151.2.   My voltmeter's resolution is 1 decimal point.
Dunno if I needed to bother as the BMS seems to do a decent job of adjusting down to what the battery needs and no more.

Well if your charger was like mine and set as high as 151.8 it's like @Chriull said the balancing cycle starts too late and lasts too short and things don't really get balanced which is bad so in that case it's definitely something one should do.

[onkeldanuel]

3 hours ago, t0me said:

I'd be inclined to be checking voltages on other things to get some idea of whether or not my voltmeter was accurate if I was getting 170v from my Lynx charger.

I adjusted output to 151.3 the just finely down till it just hit 151.2.   My voltmeter's resolution is 1 decimal point.
Dunno if I needed to bother as the BMS seems to do a decent job of adjusting down to what the battery needs and no more.

Ok, i feel Bad now.....lol

The problem was indeed my Multimeter....

I checked on the charger on my daughters KS14 and it showed 73V (should be 67)

So i changed the Batterie of the Multimeter and now it shows 67V on the KS 14

So i was able to dial the Lynx charger to 151,2 without problem

 

I have to say, i truly wasnt aware that a low Batterie on the Multimeter leads to higher/wrong voltage readings..

my bad and so learned a lesson... again !

Edited February 26 by onkeldanuel

[Rawnei]

19 minutes ago, onkeldanuel said:

So i was able to dial the Lynx charger to 151,2 without problem

What was it on before?

[onkeldanuel]

34 minutes ago, Rawnei said:

What was it on before?

I dont know because i dialed around on the Potentiometer with an offreading Multimeter, but it charged to 151,7V before...

[Seba]

On 2/24/2024 at 4:28 PM, Rawnei said:

My guess is that EUC World doesn't have full support for the Lynx yet and the PWM value we see in EUC World is not the wheel reported one but a calculation which does not match wheel PWM, maybe @Seba can clarify this?

EUC World in general fully supports Lynx (excluding BMS which is currently under development) and safety margin reported by the app and used as an input for safety margin alarm is basically an inverse of wheel-reported load value that - according to Leaperkim protocol definition - ranges from 0.00 % to 100.00 %.

I would like to note that Lynx is still a wheel with evolving firmware, has some issue that are being unde rinvestigation of Leaperkim and in overall, may still contain some bugs. It happened in history that Veteran firmwares had flaws causing it to output invalid/incorrect values, what was fixed in later firmware releases.

[Rawnei]

28 minutes ago, Seba said:

EUC World in general fully supports Lynx (excluding BMS which is currently under development) and safety margin reported by the app and used as an input for safety margin alarm is basically an inverse of wheel-reported load value that - according to Leaperkim protocol definition - ranges from 0.00 % to 100.00 %.

I would like to note that Lynx is still a wheel with evolving firmware, has some issue that are being unde rinvestigation of Leaperkim and in overall, may still contain some bugs. It happened in history that Veteran firmwares had flaws causing it to output invalid/incorrect values, what was fixed in later firmware releases.

Yeah sounds like a possibility, something feels off, hopefully they update that soon.

[Ryan5508]

Was able to get out this afternoon before work for a 8 or so mile ride. 

Pumped the tubeless street tire up to 35.5 psi to see how it would behave. 

The wheel is hard to control at that psi. Shift your weight/foot placement a hair and it dives one direction or another. And still wobbles like a mfer. 

I love the wheel but damn I am not happy with the wobbles and lack of stability. I felt safer on my v11 going 30 mph then the Lynx. Still waiting on pedal drops but I can't believe now it will help anything. I have to constantly adjust to kill wobbles that get worse if ignored. 

Not that I want to change tires already but it's starting to be an option. Mine will also lose about 1.5psi over a 4 day period currently. 

[Ryan5508]

Here is what my charger did after the first full charge. 

 

Edit - guess I forgot to screenshot it and only had the before image. 

 

 

But it made it up to 151.7 and didn't balance very well 

 

Edited February 26 by Ryan5508

[Ryan5508]

On 2/25/2024 at 5:52 AM, Rawnei said:

Measuring and adjusting is easy, I just did it, positive negative is on each side of the plug, it's also printed on the charge cover.

Adjusting: On each side of charger there are 4 screws, unscrew 4 of them on the one side where the cable with plug goes out to the wheel, other side just unscrew the top 2 ones, now you can remove the top cover of the charger, inside there is a very visible potentiometer that is blue in color with a brass/copper colored adjustment knob, left less volt, right more volt, it needs to be plugged in and you need to have multimeter in the plug while adjusting, wear gloves, use a small screwdriver and be careful not to touch other components, use plastic tool if you have but the slot is very small.

How touchy is the adjustment screw for the voltages? 

[peytole]

oui c'est ce que j'ai dit à rainu avec sa différence de 0,07. il y a maintenant une différence de 0,04. et ce sera encore mieux. Vous vous souvenez, comment nous faisions cela avant sans équilibrage visible ? Et pourtant le premier Sherman 50e a atteint plus de 20 000 kms....

 

édit 

It is completely normal that the batteries are not completely balanced during the first charges. Stop being paranoid! What did you do when there was no reader?

[Rawnei]

7 hours ago, Ryan5508 said:

How touchy is the adjustment screw for the voltages? 

You have to dial it quite a bit which is good because in reality you are setting more than one decimal.

6 hours ago, peytole said:

It is completely normal that the batteries are not completely balanced during the first charges. Stop being paranoid! What did you do when there was no reader?

We have already concluded that overcharging by that much is not optimal or desired for multiple reasons, read the thread.

Edited February 27 by Rawnei

[Rawnei]

20 hours ago, Seba said:

EUC World in general fully supports Lynx (excluding BMS which is currently under development) and safety margin reported by the app and used as an input for safety margin alarm is basically an inverse of wheel-reported load value that - according to Leaperkim protocol definition - ranges from 0.00 % to 100.00 %.

I would like to note that Lynx is still a wheel with evolving firmware, has some issue that are being unde rinvestigation of Leaperkim and in overall, may still contain some bugs. It happened in history that Veteran firmwares had flaws causing it to output invalid/incorrect values, what was fixed in later firmware releases.

Did some controlled freespin tests to see when 18% safety margin is triggered vs when wheel starts beeping:

HS Mode On: 18% Safety Margin alarm around 80kmh, wheel starts beeping around 93kmh

HS Mode Off: 18% Safety Margin alarm around 73kmh, wheel starts beeping around 81kmh

[JZT-Colorado]

10 hours ago, Ryan5508 said:

Was able to get out this afternoon before work for a 8 or so mile ride. 

Pumped the tubeless street tire up to 35.5 psi to see how it would behave. 

The wheel is hard to control at that psi. Shift your weight/foot placement a hair and it dives one direction or another. And still wobbles like a mfer. 

I love the wheel but damn I am not happy with the wobbles and lack of stability. I felt safer on my v11 going 30 mph then the Lynx. Still waiting on pedal drops but I can't believe now it will help anything. I have to constantly adjust to kill wobbles that get worse if ignored. 

Not that I want to change tires already but it's starting to be an option. Mine will also lose about 1.5psi over a 4 day period currently. 

I have lowered pedals and a knobby tire at 30 PSI and no wobbles.

I used to have a street tire on my Patton and that was definitely wobblier (sp?) than after I put a knobby on it, again running 30 PSI. Also, even before switching to the knobby I found reduced wobbles when I rode with big, heavy, stiff, over-the-calf motorcycle boots. I wanted more shoewear flexibility, so I switched to the knobby. 
 

In summary, here are the things that help wobbles:

1. Knobby instead of street tire.

2. Lower PSI in tire.

3. Lower pedals.

4. Bigger/stiffer boots.

5. An offset foot stance (I’ve heard even an offset pad placement can help with that).

6. More time & experience.

[PourUC]

2 hours ago, Rawnei said:

Did some controlled freespin tests to see when 18% safety margin is triggered vs when wheel starts beeping:

HS Mode On: 18% Safety Margin alarm around 80kmh, wheel starts beeping around 93kmh

HS Mode Off: 18% Safety Margin alarm around 73kmh, wheel starts beeping around 81kmh

Interesting test but doesn't really provide much as power draw isn't linear when weight and wind are taken into account.

From my 'testing' (strong word for ridign and checking stats).

It feels like reported PWM undergoes some sort of multiplier. Almost like the faster you are going, the higher the total PWM static value.

So with fake numbers. Imagine at 0mph travel speed. 100pwm equals 40A but once you hit 30mph or so the PWM starts to increase with you. So at 40mph it's now at 60A.

This means that you can be at like 60%PWM at 29mph but then only hit 80% at 45mph when you would expect 95% or something based on other wheels with a similar top speed. I think this is to do with their implementation of field weakening. They essentially have more of the available voltage to work with and have used the PWM value (that happens to also be reported externally) as a value to use in their calculations when determining their internal PWM for speed alarm and tilt back purposes,

It could be an easy fix. But also could require new hardware or a clever firmware update. I would imagine that the value used for tilt-back isn't even available to the bluetooth module, if it was I don't see why it wasn't caught in the first firmware update. It could be that they need to find a way to get an algorithm into the Bluetooth module (or whatever) that is able to do the same calculation that the wheels speed controller does.

I could be wrong, but I imagine it's just a tangle of badly connected components that 'just' work for the initial design. Data goes one way but not another. 

[Rawnei]

5 hours ago, PourUC said:

Interesting test but doesn't really provide much as power draw isn't linear when weight and wind are taken into account.

It's not about power draw, wheel beeps at 82% PWM, this is hardcoded and can not be changed. From doing that test we can conclude that 82% PWM (18% safety margin) does not match 18% alarm in EUC World, EUC World is triggered early i.e. the data the wheel sends over bluetooth is not correct, this is both with and without field weakning (high speed mode).

[t0me]

Do you know what the default pwm figure for tilt back is?   I haven't heard beeps,  but I have had some tiltback.   Are they at the same pwm and I just didn't hear the beeps?    I had a lot of wind noise at the time so I wouldn't be surprised.

[joyrider]

On 2/25/2024 at 2:10 PM, Rawnei said:

Not sure which screw you mean exactly but screw extractor kit or worst case if there is space to work with a Dremel to make a slot for flathead.

Use a torque wrench and torque screws to spec instead of guessing, it's a worthwhile investment getting one for tinkering with your wheels.

Raining so gonna install the preshaven Shinko 244 and replace DC converter. Any advice on torque specs? I prefer doing things proper. At least I'm not dealing with plastic.

[t0me]

1 hour ago, joyrider said:

Raining so gonna install the preshaven Shinko 244 and replace DC converter. Any advice on torque specs? I prefer doing things proper. At least I'm not dealing with plastic.

DC converter?    Something that's original or you adding a step-dn?   If the latter,  got a link to the dcdc you're planning to use?

 

[Rawnei]

5 hours ago, t0me said:

Do you know what the default pwm figure for tilt back is?   I haven't heard beeps,  but I have had some tiltback.   Are they at the same pwm and I just didn't hear the beeps?    I had a lot of wind noise at the time so I wouldn't be surprised.

Just go into the display menu and check, I have set mine to 74% which gives me a natural not noticeable tiltback that keeps me just below 80% PWM in most case unless I push with more intent. The LeaperKim tiltback is very slow and progressive you barely feel it at high speed when it activates, it just amps up at the end if you push past it.

3 hours ago, joyrider said:

Raining so gonna install the preshaven Shinko 244 and replace DC converter. Any advice on torque specs? I prefer doing things proper. At least I'm not dealing with plastic.

A lot of torque specs can be taken from Sherman S and Patton, they should be the same here:

Motor Screws M6x20 18Nm
Clamp Screws M5x14mm 8Nm
Battery to Suspension Screws (Big black countersunk ones) M6x12mm 11Nm

Other various screws: 8Nm

Screws that go into plastic: Torque by hand, not too hard, don't break plastic, don't use loctite.

 

[peytole]

Ensemble tubeless Shinko SR244.

 Perçage de 10 mm pour passage de valve tubeless.

 Retirer le côté gauche de la roue est très simple, retirez les patins pour accéder aux vis, retirez le couvercle, un côté de la poignée du chariot et les trois vis noires du pare-chocs. Et toute la batterie se détache.

 Monter le shinko tubeless, l'enfiler était facile. Un sympathique atelier qui vend des quads a claqué mon pneu avec son canon à air.

 Ensuite, nous avons dû redresser le garde-boue avec un pistolet thermique.

 Une fois en place, il frotte encore légèrement, j'ai donc nivelé les bords du pneu contre un bloc de béton.

 Du coup, la roue est « différente », on a d'abord l'impression d'être plate et qu'elle roule moins.

 Et on s'y habitue très vite car on gagne en maniabilité. Vous pouvez faire demi-tour sur place avec une grande facilité.

 Une bonne stabilité notamment sur terrain gras ou caillouteux, c'est son domaine.

 Je dois encore rouler pour m'y habituer, mais la balade d'aujourd'hui a été bien meilleure pour moi.

Edited February 28 by peytole