WTB First EUC (v8, ks16s) US

[Ash_lee_g]

Hey all, I'm looking to buy my first EUC. I have a smaller budget, but I know I'm going to love this, as I've already ridden some friends on a visit in california and got the hang of it a bit. 

My budget is around 400, ideally less, but I'm willing to spend more for a really nice wheel. Looking for a v8 in this price range, but in open to other suggestions. 

My dream wheel is a KS16s and would be willing to go up a bit on my budget as I dont think would want to upgrade for a long while, but I know that's dreaming big.  

I'm super excited and cant wait to get up and riding on my own wheel! 

[EUC Custom Power-Pads]

I started with the V8 and had a lot of fun. Good quality and very handy, but I quickly reached the limits in terms of speed, power and above all range. I was already waiting for the 16X a few months later.  

In addition, the maximum speed is throttled very quickly as soon as the battery is not even half empty. For these reasons I would not recommend it to anyone unless you are satisfied with 20-25km range and a speed of 15-20km/h for the way back. 

If I had to choose again, I would definitely choose the 16S with 840 Wh battery in your case. 

Surely there are other alternatives, but more experienced drivers should give their comments. 

It also depends mainly on what you intend to do with the wheel.

I had for example no idea what you can do with an EUC and so I decided for good quality but less power, range and low weight. In my case this was ultimately the wrong decision and if I had known what I was going to do with the unicycle, I would have bought the 16X right away, if it already existed in April 2019.

[Will R]

16s is quicker, has more torque, more range and will go longer without throttling. The new firmware also makes the acceleration very very satisfying. A very efficient running wheel also. Well worth the money, especially if you can find one second hand.

[Espen R]

I don’t know your height and weight, but since you are looking at these wheels, I guess 16” is something that suits you. EUC’s are simple and solid, so I wouldn’t hesitate to buy a second hand wheel. If I lived close to you, I would probably be willing to sell my 16S to you for something slightly north of 400 usd.

I really love the quality feel of the Inmotion wheels, so if my weight where below 165ibs, so I could ride safely on an 800W wheel, I would probably choose the V8 over the 16S. Kingsong has a more utilitarian quality feel to them while Inmotion is more like a Mercedes, everything just feels nice:)

[meepmeepmayer]

If you can get a 16S for the right price, that would be great. V8 and 14D/14S would be less pricy alternatives. But any used wheel has fantastic bang for the buck (as long as it works, not much can go wrong then).

[Ash_lee_g]

Thanks guys! I appreciate all of your responses. Good to know I'm making the right choice by searching for a v8. Of course I'd love the ks16x, but it's way out of my price range. I think a v8 is the right move in terms of budget and usability. 

Height 5'7 

Weight 175 

If any of you know of a V8 for sale, let me know please. I would like to spend no more than 400, but if the mileage is low and the outershell isn't cracked or too beat up, I'm willing to pay $500 or so

 

[mrelwood]

One thing to point out is that the battery on any wheel can be ruined quite fast with inappropriate handling. When buying used, at least make sure that the wheel charges up to 100%. Best to check the voltage from a mobile app as well. If it stops at 94% or lower, don’t listen to any excuses. The battery is already busted and costs much more to replace than the whole (used) wheel.

[meepmeepmayer]

3 hours ago, Ash_lee_g said:

Of course I'd love the ks16x, but it's way out of my price range.

Kingsong KS16S and Kingsong KS16X are two different wheels.

The 16S is a nice middle ground wheel, 840Wh battery, 35kph top speed. You saw one (in the wrong location for you, unfortunately) offered here for $700. This would be a nice price for a nice wheel.

The 16X is a big, heavy, 1600Wh, wide tire performance wheel. 

Anyways, for your stated price range a V8 seems to fit best. Or maybe something unexpected comes up.

[Unventor]

@Ash_lee_g first of welcome to your community.  I like that first post of yours a lot since you have tasted a little bit of EUC fun already you are over the first hurdle to get started. The great part here is how you are asking for advice. 

So these are my tips to your situation. When on a budget there are a few things to consider. @mrelwood are spot on with the battery consideration for a 2nd hand wheel. And this is the biggest issue that you cannot see how a wheel has been treated or any service history so it is all about the trust and if something smell fishy.  

But since you are in the US you are in luck, compared to me in Sweden where we have no "local" sellers in the country.  There have been times where Inmotion have sold refurbished wheels. So this could make it easier on you budget, but by buy from a dealer you have some level of reassurance that the wheel should be working and serviced to a level of standard.  Plus you might get some sort of warranty too. 

As you start to ride more you will get to trust your wheel and if the wheel is worn or the lifespand of the battery is bad because of number of changes done will wear out the chemistry (just like on a phone). The first indication on this is you cannot charge to 100%, in Inmotion V8 that means very close to 84V you should reach 83V+ (there might be a little inaccuracy).

[Espen R]

@mrelwood and @Unventor give you excellent advice. Li-ion battery packs are not cheap, and if they have been charged to 100% or depleted to 0% too many times, they may have lost a considerable amount of capacity, and that doesn’t just affect the range, it also limit the motors ability to draw full power from the battery pack. If you charge a Li-ion to 100% and let it sit, you aggravate the build up of the parasitic reactions that occur in the battery’s electrolyte. From 0-100%, a Li-ion battery will manage something between 300 – 1000 cycles before you start to see deterioration, but if you use a smart charger or a charge doctor and limit charge to 80-85%, and never let the wheel run beneath 20%, you’ll get up to 16 000 cycles out of your battery pack.

If the seller has followed these guidelines, then you’re safe. I used to vape, and I’ve had 18 650 batteries from Sony, Samsung and LG last for over two years being charged 100%, with almost no loss in capacity, but I’ve also had batteries from the same brands deteriorate in just a few months, so there is an element of luck here, but I wouldn’t be overly concerned about this If you follow the advice above and check the voltage at 100% charge.

My KS-16S had lived rough 100% charge life before I got it, so the first thing I ordered was a charge doctor, but I was lucky, the battery pack was and still is solid with no signs of deterioration.

[Ash_lee_g]

On 2/6/2020 at 1:18 AM, mrelwood said:

One thing to point out is that the battery on any wheel can be ruined quite fast with inappropriate handling. When buying used, at least make sure that the wheel charges up to 100%. Best to check the voltage from a mobile app as well. If it stops at 94% or lower, don’t listen to any excuses. The battery is already busted and costs much more to replace than the whole (used) wheel.

Hey there, that's for your thorough response! 

I found one local for $450, 1600m and it charges to 96% 

 

Would you say that's a good deal? 

[Ash_lee_g]

On 2/6/2020 at 4:04 AM, Espen R said:

@mrelwood and @Unventor give you excellent advice. Li-ion battery packs are not cheap, and if they have been charged to 100% or depleted to 0% too many times, they may have lost a considerable amount of capacity, and that doesn’t just affect the range, it also limit the motors ability to draw full power from the battery pack. If you charge a Li-ion to 100% and let it sit, you aggravate the build up of the parasitic reactions that occur in the battery’s electrolyte. From 0-100%, a Li-ion battery will manage something between 300 – 1000 cycles before you start to see deterioration, but if you use a smart charger or a charge doctor and limit charge to 80-85%, and never let the wheel run beneath 20%, you’ll get up to 16 000 cycles out of your battery pack.

 

If the seller has followed these guidelines, then you’re safe. I used to vape, and I’ve had 18 650 batteries from Sony, Samsung and LG last for over two years being charged 100%, with almost no loss in capacity, but I’ve also had batteries from the same brands deteriorate in just a few months, so there is an element of luck here, but I wouldn’t be overly concerned about this If you follow the advice above and check the voltage at 100% charge.

 

My KS-16S had lived rough 100% charge life before I got it, so the first thing I ordered was a charge doctor, but I was lucky, the battery pack was and still is solid with no signs of deterioration.

 

Thanks for your advice!  You guys have been so great and thorough with everything. I'll definitely be checking for those things! 

[mrelwood]

 

Quote

I found one local for $450, 1600m and it charges to 96% 

Would you say that's a good deal? 

I don’t think a beginning battery failure is ever a good deal. But 96% is admittedly a tough choice at that price, since it is possible that it can be recovered to normal. Risky, but a possible lottery win. I’d have to investigate hands on to estimate the actual odds.

EDIT: I want to emphasize that at 1600km this battery has not degraded. The cells have gone badly out of balance. Difference being that degrading happens slowly and somewhat predictably, whereas a badly balanced pack will stress the weakest cells the most, accelerating the imbalance. And when you hit that pothole, it’s up to the weakest cell to keep up. The difference in power can be easily felt.

Edited February 8, 2020 by mrelwood

[meepmeepmayer]

What wheel is that $450 one?

Usually, wheels should always charge to 100%, shouldn't they? This is probably just the charger failing, isn't it? Or something wrong with the battery?

Battery degradation is capacity loss, not loss of maximum voltage (and therefore a lower maximum charge percentage), right?

[Ash_lee_g]

6 minutes ago, meepmeepmayer said:

What wheel is that $450 one?

Usually, wheels should always charge to 100%, shouldn't they? This is probably just the charger failing, isn't it? Or something wrong with the battery?

Battery degradation is capacity loss, not loss of maximum voltage (and therefore a lower maximum charge percentage), right?

It's the inmotion v8

[Espen R]

3 minutes ago, meepmeepmayer said:

What wheel is that $450 one?

Usually, wheels should always charge to 100%, shouldn't they? This is probably just the charger failing, isn't it? Or something wrong with the battery?

Battery degradation is capacity loss, not loss of maximum voltage (and therefore a lower maximum charge percentage), right?

It's an Inmotion V8. New wheels 100%, but if you keep charging the wheel to 100%, aka not use a smart charger or charge doctor, you can start to get battery degradation pretty soon. Best case 0-100% charge gets you 300 - 1000 charge cycles, 20-80% up to 16 000 cycles. It's loss of capacity and voltage.

[mrelwood]

13 minutes ago, meepmeepmayer said:

What wheel is that $450 one?

I understood it to be the 16S. (EDIT: Sorry, it’s a V8. I’d pass on the deal.)

Quote

Usually, wheels should always charge to 100%, shouldn't they? This is probably just the charger failing, isn't it? Or something wrong with the battery?

Either a failing charger, which would be a cheap fix, or a bad battery imbalance that stops the charge when the highest charged cells reach around 4.25V.

When the imbalance gets bad enough, the cells can no longer be balanced by a careful charging plan, since the charging will stop before any notable balancing takes place in the CV stage of the charging.

The 16S doesn’t seem to use very good battery cells. I have 10k km on mine, and I have had to replace dead cell pairs at 4k and 8k. And currently the voltage span of the cells is again about .5V, so the charging stops at 91%. I don’t know if I can still salvage the packs without replacing yet another pair of bad cells.

My MSX at 10k km shows zero degradation or cell imbalance.

Edited February 8, 2020 by mrelwood

[mrelwood]

 

5 minutes ago, Espen R said:

if you keep charging the wheel to 100%, aka not use a smart charger or charge doctor, you can start to get battery degradation pretty soon. Best case 0-100% charge gets you 300 - 1000 charge cycles, 20-80% up to 16 000 cycles. It's loss of capacity and voltage.

Note that no wheel lets the batteries drain down to anywhere near the universal Li-ion 0%, which is something like 2.5V. If a V8 can reach 20 miles on a charge (fe. 4.2V to 3.2V per cell), a full charge cycle gets about 35 miles of range. Already the minimum 300 cycles is past 10 000 miles. That could already be a world record on a V8.

So battery degradation is not a real issue on an EUC. But if you limit the charge to 80% and never do any balancing, you will most probably have to replace the pack already at 2000 miles at the latest.

[Ash_lee_g]

@meepmeepmayer @mrelwood @Espen R @Unventor

Here's a link to the diagnosis run on the v8

https://filebin.net/sj1xjhrqe9ujqqsc

 

Thank you guys so much for your input and advice! 

 

[meepmeepmayer]

6 minutes ago, Ash_lee_g said:

Thank you guys so much for your input and advice! 

This must be very confusing for you. I certainly am unsure.

In doubt, I'd pass on this. 96% charge seems... strange to me. Best case, you'd still have to get a new charger so you can balance the battery cells again.

Maybe ask if a price reduction is possible?

I'm not sure what is best here. But this offer isn't running away, is it? Maybe you find an alternative in the mean time.

[Ash_lee_g]

@meepmeepmayer no the offer is definitely no running away. I dont think the guy is trying to pull anything over, as I was the one to seek him out about the EUC. But I'll definitely keep my eye open. It's just been challenging finding someone local in Texas 

 

Thanks for all your feedback, I definitely feel more educated in what to look for! 😊

[meepmeepmayer]

Used EUCs are simple: if one works flawlessly (balances etc.), has no obvious serious mechanical crash damage, and shows no other strange symptoms (like not charging to 100%), pretty much nothing can be wrong. So if one of these warning signs pops up, that is cause to be cautious.

It may very well be his charger isn't good, thus he never charged to 100% or allowed the cells to balance, and only one charge with a good charger is needed so the wheel charges to 100% and is perfectly fine again. But you don't know for sure, even if that's the likeliest explanation (as far as I can say).

[Espen R]

1 hour ago, Ash_lee_g said:

@meepmeepmayer @mrelwood @Espen R @Unventor

Here's a link to the diagnosis run on the v8

https://filebin.net/sj1xjhrqe9ujqqsc

 

Thank you guys so much for your input and advice! 

 

Hard to give you a definite advice. If you take care of the battery and limit the charging to 80-85%, the battery pack might re-balance itself and work perfectly for years to come. But, 96% could also indicate a bit more than just a few dud cells, and you could get sudden voltage drops, so when you are out riding the wheel could suddenly drop from something like 60% remaining capacity to 15%.

I know you really want a wheel, but you are in risk of wasting 450 usd, and that’s a bummer for most people. I would probably pass, if it was me buying this wheel.

[Ash_lee_g]

1 hour ago, Espen R said:

Hard to give you a definite advice. If you take care of the battery and limit the charging to 80-85%, the battery pack might re-balance itself and work perfectly for years to come. But, 96% could also indicate a bit more than just a few dud cells, and you could get sudden voltage drops, so when you are out riding the wheel could suddenly drop from something like 60% remaining capacity to 15%.

 

I know you really want a wheel, but you are in risk of wasting 450 usd, and that’s a bummer for most people. I would probably pass, if it was me buying this wheel.

 

Thank you for the solid advice, I'll keep an eye open for something else that fits my price range. I really appreciate eyou taking the time to break everything down. I'm super excited to have found a community of such awesome and welcoming individuals! 

[mrelwood]

7 hours ago, Espen R said:

If you take care of the battery and limit the charging to 80-85%, the battery pack might re-balance itself

To be precise, balancing only happens at the very last stage of charging. If you always stop the charging at 90% or below, balancing will never happen and the cell voltages will drift being further unbalanced.

To balance a battery pack that doesn’t charge to 100%, one should have it plugged in the charger at 90-100% charge for as much as possible. Fe charge to full, ride a few miles only, charge to full, and repeat.