The KS16 Firmware Thread

[HEC]

5 minutes ago, Keith said:

 

Firstly, a higher capacity battery will sag less under load than a small capacity battery so the voltage will be higher, under any given load, with a 754Wh battery than it is with (say) 174Wh battery.

Secondly, if the voltage is down to (say) 58V under load then sudden acceleration, or (say) over leaning will have much the same effect regardless of whether you have a 754Wh battery or a 174Wh battery.

You contradicting yourself in above two statements and indeed the second one is incorrect ... The "effect" will be greatly different for 1P, 2P or 4P pack under otherwise matching ride conditions.

[Keith]

3 minutes ago, HEC said:

You contradicting yourself in above two statements and indeed the second one is incorrect ... The "effect" will be greatly different for 1P, 2P or 4P pack under otherwise matching ride conditions.

No I am not, let's say (just pulling numbers out of the air), that a (1P) 174Wh battery at a given load is down to 56V at (say) 80% of capacity,  but a (4P)754Wh battery doesn't drop to that voltage under the same load until it is down to (say) 30% of capacity. You really think a bigger battery at a very much lower level of charge is going to deliver more power than a smaller battery at much higher level of charge? Under the same load, but at significantly different levels of charge they both sagged to 56V why would one  suddenly be able to deliver a lot more power than the other.

That is why I put those statements in bold.

[vido]

11 hours ago, ThomasK said:

I am on v 1.20 on my KS16. No, the "Hello KingSong" and "Bluetooth is connected" are shouting immediately upon switching the light settings to On. Only if you switch the sound off again immediately after that (before turning off the wheel), the KS stays quiet. Switching the KS off, the light settings return to "Auto".

Battery (754 Wh) is at 43% with 58.0 V and the speed limits are not altered. So it seems to me that the voltage is triggering the changes to the speed limits and not the battery level in %.

That's strange I just drained my battery to 30% today(840 wh). As soon as I hit the 50% mark my speed alarm sounds off at 28kmh and decreases further when battery becomes less. @Cloud has also tested my kingsong. 

[dmethvin]

I agree with you @Keith that the voltage under load is the important thing. I don't agree that 58V under load will have much the same effect regardless of the battery capacity. When put under a higher load, don't you think the smaller battery will sag even more? It's dealing with a higher internal resistance for that case because there are fewer parallel cells.

If the KS is putting on a speed limit when a 754Wh battery still has half its capacity, it seems too paranoid to me. There need to be more inputs than voltage so that it isn't crazy conservative, for example the total battery capacity, the rider's weight, maybe even dynamic inputs regarding the recent voltage fluctuations.

[HEC]

8 hours ago, Keith said:

You really think a bigger battery at a very much lower level of charge is going to deliver more power than a smaller battery at much higher level of charge?

Yes. Lets say you have 2 packs - both at 58V under the load during normal cruise (say 250W being used). Then suddenly you'll  quickly speed up (due to road condition or whatever) and need for short time to use 1200W:

Pack A ("1P"):

Normal ride 250W / 58V -> 4.31A from the whole pack as well as from each cell

Speed up 1200W / 58V ->20,69 A from the whole pack as well as from each cell

Pack B ("4P"):

Normal ride 250W / 58V -> 4.31A from the whole pack but only 1.08A from each cell

Speed up 1200W / 58V ->20,69 A from the whole pack but only 5.17A from each cell

While pack A might not even be able to deliver the current over 20A at this situation resulting in BMS or controller cut-off as the voltage sag will be simply bellow it's lower discharge limit per cell resulting in FACEPLANT the Pack B might still remain well above the cut-off / damage threshold pulling only about 5A (e.g. one quarter comparing to A - almost the same current as pack A was pulling during normal crusie) from each cell keeping you safely upright and cruising.

Edited July 15, 2016 by HEC

[Chriull]

 

3 hours ago, dmethvin said:

I agree with you @Keith that the voltage under load is the important thing.

Me too - a very nice approach

3 hours ago, dmethvin said:

I don't agree that 58V under load will have much the same effect regardless of the battery capacity. When put under a higher load, don't you think the smaller battery will sag even more? It's dealing with a higher internal resistance for that case because there are fewer parallel cells.

As @Keith said he was just pulling numbers out of the air. To get a little bit more detailed (but still ignoring the internal cell chemistry like changing internal resistance, etc):

The internal resistance of a LG MJ1 (just as an expample - for this i found the number) is 37 mOhm - so for 16 cells in serie this sums up to 0,592 Ohm. Lets assume a load of 10A which means about ~580W - quite normal or about 1.5 to 2 times the power required for cruising along a leveled straight road.

If under this premises the wheel measures 58V from the battery pack, this means that at the internal resistance of an

- 1p Pack  5,92V

- 2p Pack 2,96V

- 4p Pack 1,48V

are dropped. So the internal Voltage of the battery packs would be for 1p 64V, for 2p 61V and for the 4p 59,5V. Again ignoring the chemistry this would be the no load voltages of the packs (which they should roughly reach after some break and show a more exact value of the left capacity as the "under load voltage").

This would mean the KS16 shows for the 1p pack 9 Leds, for the 2p pack 7 Leds and for the 4p pack 6Leds out of 9 Leds.

3 hours ago, dmethvin said:

If the KS is putting on a speed limit when a 754Wh battery still has half its capacity, it seems too paranoid to me. There need to be more inputs than voltage so that it isn't crazy conservative, for example the total battery capacity, the rider's weight, maybe even dynamic inputs regarding the recent voltage fluctuations.

So for the first Speed Limit (55V) and the same assumptions (37 mOhm per cell internal resistance and 10A load) this would mean for a:

- 1p Pack: 61 V"internal" Voltage - 7 out of 9 Leds

- 2p Pack: 58V "internal" Voltage - 5 out of 9 Leds

- 4p Pack: 56,5V "internal" Voltage - 4 out of 9 Leds

So imho a very nice idea implemented from KS - maybe the limits could be changed a bit. Did not try it out to often on my KS to give a real statement if it is annoying or ok for me. Is also hard to judge/guess if one drives safely with the speed limit if one would faceplant at full speed...

[Chriull]

Edit: There are some discrepancies with the charts/tables/measured values at dampfakku.de (at least for the cell i took for my post below) - so this values are not really significant. My feeling would be, that the real values (i trust the table values more;) are better

 

And some more numbers regarding this topic. At http://www.dampfakkus.de/akkutest.php?id=608 is not only the internal resistance of the LG MJ1, but also the charts for discharging these cells for different discharge currents (cell voltage over used capacity). Using this should lead to more practical figures regarding battery usage:

Assumptions/Premises: I took the numbers of the 10A (1p battery pack), 5A (2p Battery pack) and 3A and 2A (2,5 would be the same load for a 4p pack). The points on the chart i looked at where for 55V - 1st stage speed reduction (means 55V/16=3,44V per cell) and 50V - limp home mode, more or less end of usable capacity (50V/16 cells=3,125V per cell)

The resulting used mAh per cell i multiplied again with 3,7V (nominal cell voltage used for factory Wh numbers) to get some feeling too for the Wh numbers printed on the packs...

1p Battery pack - discharge with 10A (500-600W "constant" load): *)

used nominal Wh until 55V: 41.5, until 50V: 99Wh -> 100% usable capacity 99Wh, at (99-41,5)/99=58% capacity first speed reduction

2p Battery pack - discharge with 5A (500-600W "constant" load): *)

used nominal Wh until 55V: 55,6, until 50V: 105Wh -> 100% usable capacity 105Wh, at 46% first speed reduction

4p Battery pack discharge with 3A (600-720W "constant" load):

used nominal Wh until 55V: 247, until 50V: 398Wh -> 100% usable capacity 398Wh, at 38% first speed reduction

4p Battery pack discharge with 2A (400-480W "constant" load):

used nominal Wh until 55V: 425, until 50V: 621Wh -> 100% usable capacity 621Wh, at 31% first speed reduction

 

The theoretic Wh given from the manufacturers (nominal Voltage (3.7V) * 16 cells * nominal Ah (3500mAh for LG MJ1)) would be:

- for the 1p Pack: 207Wh

- for the 2p Pack: 414 Wh

- for the 4p Pack: 828 Wh

Once i find some indication which cells are really used in the KS16 i will repeat this number for ~250W load which should be in the range of normal cruising on a leveled road. As the numbers here show with higher discharge rates and the internal limit of 3,125 A the battery packs can only deliver a fraction of their nominal capacity.

*) The 1p and 2p numbers lead to almost the same total and used Wh which seems very strange! On dampfakkus.de the 10A chart is published in another form as the 5A,3A and 2A charts - so it seems they used some different methodology/different batch of cells for this numbers and this could explain the strong deviations of this numbers. Or the Lg MJ1 gets another peak at 10A discharge....

Edited July 15, 2016 by Chriull

[US69]

1 hour ago, Chriull said:

*) The 1p and 2p numbers lead to almost the same total and used Wh which seems very strange! On dampfakkus.de the 10A chart is published in another form as the 5A,3A and 2A charts - so it seems they used some different methodology/different batch of cells for this numbers and this could explain the strong deviations of this numbers. Or the Lg MJ1 gets another peak at 10A discharge....

That's a total normal behaviour of every Batterie which is rated for high amp discharge rates....if you are constantly pushing high amps the batteries tend to give much less than the rated mah

[Chriull]

2 hours ago, KingSong69 said:

That's a total normal behaviour of every Batterie which is rated for high amp discharge rates....if you are constantly pushing high amps the batteries tend to give much less than the rated mah

Yes - i know. Also the drop for the 4p (828Wh nominal) pack is quite impressive - with 2A load one can "use" 620Wh, with 3A only ~400Wh anymore. Thats a drop from 75% to 48%!

The "strange" figures resulting from the chart i meant is, that with an 1p Pack and 10A load one can use 47% of the nominal capacity (99Wh from 207Wh nominal) and with the 2p Pack with only 5A load on could use just 25% (105Wh of nominal 414Wh)!

So with this extreme figures i would suggest to "handle" this dampfakku discharge graphs "with care". Maybe there are quite some deviations in different batches of cells, maybe the newer batches got extremely improved or there changed some other circumstances/parameters (measurement setup and/or conditions, ambient temperature, ...)

I made a summary of the different discharge currents per cell to get an overview:

So i am quite glad i decided for the 4p pack for my KS16

PS.: For these figures i have choosen the LG MJ1 battery cells- I have no idea which battery cells are used for the KS16, how their discharge characteristics are, but i hope that this could give a rough picture...

Edit: There are some discrepancies with the charts/tables/measured values at dampfakku.de (at least for the cell i took for my sheet above) - so this values are not really significant. My feeling would be, that the real values (i trust the table values more;) are better

Edited July 15, 2016 by Chriull

[US69]

17 minutes ago, Chriull said:

 

PS.: For these figures i have choosen the LG MJ1 battery cells- I have no idea which battery cells are used for the KS16, how their discharge characteristics are, but i hope that this could give a rough picture...

You are absolutly right with the LG MJ1....There are only 2 or 3 other "real/no repack" in the 3500mah Range existing ....and as KS i stating LG on their 840wh Version this is the only possible.....

As dampfakkus  has an excelllent Reputation and the quys are also excellent in testing electronics like chargers etc .... in General i do not think they Change their Setup "inbetween" without to mention it....but no clue what this jump Comes from?

These guys also have a Forum, the best cells are also dicussed there....but as These 3500 mah cells "only" have a 10Amp Rating...they are not the vapers (=dampf) first choice

That would be the LG HG2(3000/20A) which is unfortunaly not used till now in our wheels...in the 680wh Version the LG MG1 (2850/10A) is used

[Chriull]

1 hour ago, KingSong69 said:

...As dampfakkus  has an excelllent Reputation

That's my feeling, too!

1 hour ago, KingSong69 said:

and the quys are also excellent in testing electronics like chargers etc .... in General i do not think they Change their Setup "inbetween" without to mention it....but no clue what this jump Comes from?

I just took a closer look an the LG MJ1 Test Page - The have there quite some difference between the chart and the table of measured values. i.e. from the chart discharged with 2A until 3V got a used capacity of 2722mAh, in the table is writte 3039 mAh.... ;( As it seems there got something a bit mixed up...

I tend to trust more in the table as in the chart, so the usable capacity of the cells should be better than my above post show.

[US69]

43 minutes ago, Chriull said:

That's my feeling, too!

I just took a closer look an the LG MJ1 Test Page - The have there quite some difference between the chart and the table of measured values. i.e. from the chart discharged with 2A until 3V got a used capacity of 2722mAh, in the table is writte 3039 mAh.... ;( As it seems there got something a bit mixed up...

I tend to trust more in the table as in the chart, so the usable capacity of the cells should be better than my above post show.

Hmmh,

 

this difference between table and curve i can found everywhere......perhaps i/we understand something wrong? I really dont know....

[Jason McNeil]

The take home message, I guess, here is that that setting an artificially low 'out-of-battery' of say 55v (like the original high capacity KS/GWs) means that you're going to be loosing a lot of those precious Wh's that you've paid for.

8 hours ago, Chriull said:

drop for the 4p (828Wh nominal) pack is quite impressive - with 2A load one can "use" 620Wh, with 3A only ~400Wh anymore. Thats a drop from 75% to 48%!

Yeah, that's pretty damn unlikely! One pretty important aspect for battery usage on a Wheel is the Peukert Cure, or the difference between the intermittent discharge (a Wheel) and the continuous discharge that they perform in the labs. The advantage for our application, is that the outlook is a great deal better for the spiky nature of Wheel usage than under sustained load, even the internal resistance is lower—lab result would be DC impedance, which is invariably worse.

It should also be noted that KS are now starting to use the Sanyo GA for their high capacity packs: they're really very close in general spec, but it seems that the GA has a slight upper edge (5% better) under high 10A loads.

https://yunergybattery.wordpress.com/

On the eBike forum, there's a couple others who have questioned some of Dampfakkus's results with the MJ1 cell.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=70147&start=25#p1062171

They recently reviewed the MG1 but something's wrong with their data: the Official info from LG themselves for the MG1 (for the 680Wh pack) has an internal resistance figure (AC) of ~35mΩ but Dampfakkus has 22mΩ  

Dampfakkus: http://www.dampfakkus.de/akkutest.php?id=642
Official Datasheet: http://www.sot.com.tw/images/11.pdf

Edited July 15, 2016 by Jason McNeil

[Chriull]

Update: As it seems the numbers of dampfakkus.de are "correct", just the mAh from the x-axis from the 2,3 and 5A charts are incorrect - but the raw voltage data can be copied from the side and with the sample intervall of 2s everything can be calculated.

So here the hopefully right numbers for the comparison of 1p,2p and 4p packs for LG MJ1 with 2,3,5,10 and 20A load:

battery usage 2.pdf

[Fernembo]

On 2/6/2016 at 5:17 AM, Jeffrey Scott Will said:

This topic has been discussed in various threads, but since the firmware upgrades will be an ongoing process, I figured it deserved a place we can all reference when new versions come out.

As I mentioned elsewhere, I impulsively upgraded to V 1.20 against recommendations from my seller that I wait until the stability in confirmed. I commuted with it today which includes plenty of stresses with prolonged hill climbs and descents, high(ish) speeds(22-23kph) and idling. It's only been one day, but so far so good. Not a beep or any indication of struggle. Felt just like V 1.15 which is what I was upgrading from.

So my personal verdict so far: 

V 1.20  Thumbs up

Perhaps the brave souls who try new releases can all chime in so others can decide for themselves if they would like to upgrade. Personally, if this is your only wheel, I'd wait a few weeks until enough reports come in before jumping the gun like I did.

My KS16B arrives today... so I am still not sure whether to go for V 1.20 or not. Anyone else ordering the new 16B from France runs V 1.20 with no issues?

[Polpus]

@Fernembo no matter where the EUC comes from , the important thing is that it's a KS16B with fw V 1.20.
 I upgraded it starting from V 1.13 and no issues so far .. even if I'd love to lower that speed limit at 30 % of battery because also in my opinion it's way too conservative to decrease the speed limit at 50 % of battery and yes when I find stright road with no person I love to go fast...

[HEC]

12 minutes ago, Fernembo said:

My KS16B arrives today... so I am still not sure whether to go for V 1.20 or not. Anyone else ordering the new 16B from France runs V 1.20 with no issues?

What FW you have now - v1.19? If yes I'm riding on that one since I've received my wheel and the only difference from v1.20 is the speed limitation introduced in 1.20. However both seems to suffer with the below issue so be careful:

 

[Fernembo]

5 minutes ago, Polpus said:

@Fernembo no matter where the EUC comes from , the important thing is that it's a KS16B with fw V 1.20.
 I upgraded it starting from V 1.13 and no issues so far .. even if I'd love to lower that speed limit at 30 % of battery because also in my opinion it's way too conservative to decrease the speed limit at 50 % of battery and yes when I find stright road with no person I love to go fast...

Thank you, @Polpus and @HECSo how can I know for sure it already has FW V 1.20? I downloaded the app here and under Firmware Upgrading I am given the option to download Ks-16B V1.20... I still do not have the wheel in my hands as of right now (can't wait!) So I guess once I connect it to the app the FW will be displayed somewhere?

 

3 minutes ago, HEC said:

What FW you have now - v1.19? If yes I'm riding on that one since I've received my wheel and the only difference from v1.20 is the speed limitation introduced in 1.20. However both seems to suffer with the below issue so be careful:

 

@HEC thanks for that, will wear full body armour on the first rides just in case.

[HEC]

5 minutes ago, Fernembo said:

Thank you, @Polpus and @HECSo how can I know for sure it already has FW V 1.20? I downloaded the app here and under Firmware Upgrading I am given the option to download Ks-16B V1.20... I still do not have the wheel in my hands as of right now (can't wait!) So I guess once I connect it to the app the FW will be displayed somewhere?.

Yes - the app will display current FW version installed on the wheel.

[Chriull]

 

2 hours ago, Polpus said:

@Fernembo no matter where the EUC comes from , the important thing is that it's a KS16B with fw V 1.20.
 I upgraded it starting from V 1.13 and no issues so far .. even if I'd love to lower that speed limit at 30 % of battery because also in my opinion it's way too conservative to decrease the speed limit at 50 % of battery

The speed limit comes at about 30% of battery capacity left. (If one takes the capacity of the start of the limp home mode as 100% usable capacity).

Just if one takes the percantage relative to the nominal (but not usable) capacity one is about 50% with the 1st speed reduction....

With a 4p Pack (the 828Wh version with LG Mj1, ?also the 680Wh is a 4p with different cells?) the average current consumption should be less than 2A per cell, so the speed limit should come at a bit less than 30% of battery capacity remaining - but dampfakku.de has no charts for lower loads than 2A.

2 hours ago, Polpus said:

and yes when I find stright road with no person I love to go fast...

Me too!  Also with some nice (adequate) curves - that's imho even better!

On 21.7.2016 at 11:04 AM, Chriull said:

So here the hopefully right numbers for the comparison of 1p,2p and 4p packs for LG MJ1 with 2,3,5,10 and 20A load:

battery usage 2.pdf

This time i introduced a typing error... ;(

Here the (now hopefully) right values with the addition of percentage of used capacity at 1st speed reduction versus capacity used at limp home mode:

battery usage 2.pdf

ps.: I never verified that power consumption of an KS16 driving ~30km/h is still in the about 250-300W range. I still have this numbers from my E+... ;(

 

[Chriull]

2 hours ago, Fernembo said:

 

@HEC thanks for that, will wear full body armour on the first rides just in case.

If you read on in this thread, you'll see that this issue happens only when starting to drive from standstill (or standing in a "hole"):

 

But wearing some nice protection is anyhow very recommandable - with every existing EUC you have a small but existing chance of a top speed faceplant!

[Ogg V0rbis]

hey guys. Apologies in advance for jacking the thread, but I'm having trouble updating my firmware on my 14B. I select my unicycle on the firmware update page, hit download, then hit update and it takes me to a page of notes. nothing seems to happen. Any thoughts? Thanks regardless!

[HJ]

 Hi, have a really basic and probably stupid question here but, I have my KS – 18 for over a year now, and I've never upgraded the firmware. I went to try to do to it today, and I can't. When I go on the app, the new app, under firmware upgrade it just says "V0.00"is there something I'm missing here? What is the actual process to upgrade. I don't see any other options from my app. Thanks in advance.is there something I'm missing here? What is the actual process to upgrade. I don't see any other options from my app. Thanks in advance.

[HJ]

 I am able to connect, and it reads voltage, speed, etc. Also, is there anyway to have it read in miles per hour versus kilometers per hour ?

[HJ]

Lastly terminal when I go to the upgrade firmware part of the app, there is no button to download or anything. Just a blank screen other than saying it's "v0.00". I'm using an iPhone 6