battery already at the end? V10 F - 10 months old

[MBIKER_SURFER]

Hi all,

 

I'm realizing, that my mileage dropped dramaticly since 2018. Same routes - always windy - a bit colder. But consumption rises from 17 W/km to 22 W/km. So actually, a max. of 40 km is realsitic. That is a bad joke. Last year, 50 km rides were possible. Although my average speed on my rides are lower than last year. Any explanation?

Using original standard charger 120W by inmotion! 

[meepmeepmayer]

How many charge cycles (wheel overall distance/50km)?

I would suspect the charger, does it charge to 100%? Try keeping the charger in for a few hours after the light goes green and do a range test then.

Batteries shouldn't get worse that fast unless you have like 25000km or 50000km on your V10F.

Cold weather and wind will reduce your range, though. A notable reduction.

Edited May 17, 2019 by meepmeepmayer

[Chriull]

@MBIKER_SURFER as written wind and cold weather can be a eeason, also different riding style (going faster, more accelerations)

Charger could gave started to deliver less voltage - don't look at the charge percent but the voltage reported! The voltage range for 100% charge shown   is huge and a big capacity difference.

If it's the battery i collected some thoughts here:

 

[MBIKER_SURFER]

Well - as written - the only reason for me could be, that temperature wasn't too high. We had all time max. of 10° C plus wind. But wind here is more than normal. 4 bft is 'no wind'.

And I documented km, conditions and average speed. As written, in 2018 average speed was higher - but mileage also roughly 20%.

Charger - no experience. When the blue LED's are constant on, it takes about 60 min until the green LED on the charger says - fully loaded.

Edited May 17, 2019 by MBIKER_SURFER

[MBIKER_SURFER]

Number of charges: 165

[Chriull]

10 hours ago, MBIKER_SURFER said:

Well - as written - the only reason for me could be, that temperature wasn't too high. We had all time max. of 10° C plus wind. But wind here is more than normal. 4 bft is 'no wind'.

10°C could be already a reason? But i never really looked at the range - and i try to avoid driving at such temperatures 😎

3 hours ago, MBIKER_SURFER said:

Number of charges: 165

Theoretically everything should be fine with such a number, but it's no security. One can get bad batteries with low charge count too. 

 

[Mono]

14 hours ago, MBIKER_SURFER said:

I'm realizing, that my mileage dropped dramaticly since 2018. Same routes - always windy - a bit colder. But consumption rises from 17 W/km to 22 W/km. So actually, a max. of 40 km is realsitic. That is a bad joke. Last year, 50 km rides were possible. Although my average speed on my rides are lower than last year. Any explanation?

When do you charge the battery to 100%, right after you get home or right before you start riding?

If you store a battery (every night) fully charged for 10 months, a capacity reduction to 80% is not very surprising to me. That is, if you charge up the battery to 100% each time after you get home, I wouldn't be surprised by the degradation. If you charge the battery to 100% always only right before to start riding it would be more unusual.

Edited May 18, 2019 by Mono

[MBIKER_SURFER]

My V10 F never stands for more than 1 week without riding. Normally max 2 or 3 days - if it is raining.

Today it was charged before riding. Voltage was 83,7 V on Start. Low wind - 20° C - average riding speed lower than 25 hm/h - but consumption was more than 21Wh/km. Something is wrong here. Max mileage therefore is only 40 km - ridiculous.

Edited May 18, 2019 by MBIKER_SURFER

[Mono]

58 minutes ago, MBIKER_SURFER said:

My V10 F never stands for more than 1 week without riding. Normally max 2 or 3 days - if it is raining.

I don't think the relevant parameter is for how long the battery is resting in a row, but whether it is charged to 100% while it is resting more often than not. Even if you ride every day, if you charge the battery to 100% each time you stop riding, it rests at 100% for a very long cumulated time.

58 minutes ago, MBIKER_SURFER said:

Today it was charged before riding. Voltage was 83,7 V on Start. Low wind - 20° C - average riding speed lower than 25 hm/h - but consumption was more than 21Wh/km. Something is wrong here. Max mileage therefore is only 40 km - ridiculous.

How do you measure consumption? BTW, increased consumption per km doesn't really suggest a failing battery. After all, in this case you consumed the Whs the battery stored. A failing battery would mean to have less Whs to consume.

Edited May 18, 2019 by Mono

[Chriull]

1 hour ago, MBIKER_SURFER said:

ridiculous

Unfortionately not

As @Mono stated and in https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries is written that a li ion battery stored for a year at 100% has only 80% capacity left. So his question, how your charging routine is.

So if one charges after every ride and the battery has by this in average mostly 100% charge something around a 20% capacity drop after a year is "normal".

If one charges just before a ride and inbetween the battery sits with something around 30-60% the capacity drop by this will be much lower to neglectable.

Also the stated 3-500 charge cycles from the cell manufacturers are valid for ~0.2C discharg currents. With EUCs the burden should be mostly higher.

This was until now just the effects tor single cells. In the used packs are many cells in serie which "increased capacity loss problems/occurances".

For one the chance to get a not so good cell rises, and on the other side the weakest cell in a pack gets the most stress and by this degrades even faster.

1 hour ago, MBIKER_SURFER said:

Today it was charged before riding. Voltage was 83,7 V on Start.

A one time voltage measurement is unfortionately not too meaningful. Normal measurement devices are too inaccurate - one needs normally some values over time to compare and see a trent. ...and hope that ones multimeter did not drift too much over time ...

Edit:

...and additionaly your charger could get misadjusted over time to just deliver less maximum voltage and so less charge into your batteries.

Edited May 18, 2019 by Chriull

[MBIKER_SURFER]

Well - and what is the solution? I'm a poor user.

If my battery is low - I have ti charge it. With original charger, hoping, the routine inside there ist optimum für the battery.

Normally I'm riding once a day - so coming home, the battery is charged for the ride next day. What am I doing wrong?

Consumption is measured saying that my battery has 100 % capacity.

I agree, this maybe misleading. 

But as user, I don't mind what is the reason for much less mileage.

As stated - roughly 170 times charged. 

Any chance to tell my battery, I want 100 % capacity inside there 

[Mono]

6 hours ago, MBIKER_SURFER said:

If my battery is low - I have ti charge it. With original charger, hoping, the routine inside there ist optimum für the battery.

You do not have to charge when the battery is low (and should not when it is still hot), you only have to charge before to use the battery. The original charger is not a problem, as long as it takes more than 90 minutes to fully charge the battery from 0 to 100%.

6 hours ago, MBIKER_SURFER said:

Normally I'm riding once a day - so coming home, the battery is charged for the ride next day. What am I doing wrong?

As @Chriull and myself wrote above. Charging the battery to 100% for riding the next day is "wrong". Charging it right after riding is also not ideal, because then it may be quite warm.

6 hours ago, MBIKER_SURFER said:

Any chance to tell my battery, I want 100 % capacity inside there 

Here is what I do: when I come home I wait and let the battery cool down (ideally for at least two hours). Then I charge to about 50-60%. Then, right before to leave, I charge to about 80%, which takes usually about an hour. If I need more capacity, I charge longer and up to 100% if necessary. I have a timer that allows to charge for 1/4h or 1/2h or 1h or 2h etc. Ideally, I would also like to be able to choose 3/4h and 1.5h, but 1/2h and 1h is in general good enough. I also have a charge doctor, but with the timer it has almost become superfluous.

Edited May 18, 2019 by Mono

[MBIKER_SURFER]

Hm - not possible for me. I have to load to 100% - because I'm always running out of battery and riding often the last 10 km at max of 20 km/h to come home without going by foot.

The battery is too small - resp. the consumption to high. Realistic spoken: I need another EUC with at least 1500 Wh. But as long as we are not allowed to ride officially, I won't invest another 2 k in a new EUC.

[MBIKER_SURFER]

By the way: Checked today temperature on arrival with low battery: 39°C. 10 in later, I started charging - took 10 hours until green led of charger light up.

[Mono]

1 hour ago, MBIKER_SURFER said:

Hm - not possible for me. I have to load to 100%

I guess you didn't read until "If I need more capacity, I charge longer and up to 100% if necessary."  Anyways, it's your battery, not mine 

Edited May 18, 2019 by Mono

[MBIKER_SURFER]

Of course - I read your statement. But how many hours have your day? 24 plus the night?

That's the problem. Charging the V10 F to 100 % takes roughly 10 hours. So coming home at 18:00 is a about 7 hours up to bedtime and the rest in the morning - and than the next ride.

With 80% charged wheel - I can stay at home!

So - how can I optimize, if a day (incl. night)  has only 24 hours? 

[Chriull]

16 hours ago, MBIKER_SURFER said:

So - how can I optimize, if a day (incl. night)  has only 24 hours? 

 

On 5/18/2019 at 11:45 AM, MBIKER_SURFER said:

My V10 F never stands for more than 1 week without riding. Normally max 2 or 3 days - if it is raining.

Be sure that the battery is not at 100% while this not driving days.

You could think of a "fast" charger - with 0.5C the battery should be charged within 3-4 hours. If you precharge to ~50% after the ride (and some "break" time for the batteries) some 2-3 hours in the morning should be enough for 100%.

The V10F has two battery packs 20s2p with 3200mAh cells? If so 0.5C would be 6.4A - a bit too much for plugs/wiring. 5A chargers are available and mostly plugs can take this.

And some cells have the manufacturer recommendation to charge with a bit less than 0.5C.

Ewheels state 2h to 80% with their 5A charger. So this precharging in the evening and charging the rest in the morning could work out to reduce "drasticly" the time with full charge for the cells.

... If you have enough time in the morning :(....

On 5/18/2019 at 11:45 AM, MBIKER_SURFER said:

Today it was charged before riding. Voltage was 83,7 V on Start. 

Keep an eye on the voltage after full charge. If its steadily dropping this could be a first sign of bad/aged/misbalanced cells...

[MBIKER_SURFER]

Thanks - I will try to change my 'charging behaviour'. I already ordered a charger with 3 A instead of the original with 1,5 A.

[Mono]

32 minutes ago, Chriull said:

You could think of a "fast" charger - with 0.5C the battery should be charged within 3-4 hours.

Doesn't 0.5C by definition mean that the battery can be charged within 1/C = 2h?

I agree with the solution. Charging at around 5A (if the wheel is build to withstand this charge current) should improve the situation in terms of flexibility.

Otherwise, @MBIKER_SURFER, if you charge for 10h during the night and leave in the morning, this should IMHO not lead to such a significant over-degradation of the battery, as it leaves the battery only a couple of hours per day at 100% charge. Then the remaining cause of degradation could be charging the heated battery right after usage.

The other caveat with overnight charging is that unattended charging is generally discouraged, because the fire risk seems to be somewhat larger while connected to the charger.

[Chriull]

2 minutes ago, Mono said:

Doesn't 0.5C by definition mean that the battery can be charged within 1/C = 2h?

Should be. But with Li Ion's that's "just" the C(onstant)C(urrent) phase which charges the cell to ~85%. Charging the cells with C(onstanst)V(oltage) up to 100% takes longer. Just seen here at https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries were a 1C charge is shown that after 1 hour CC there are ~2,5hours of CV. So maybe my assumptions for charging time in my above post have too be adopted a bit to longer times... Or its just the last percentages (and balancing) happening and not really necessary for each charging?

2 minutes ago, Mono said:

I agree with the solution. Charging at around 5A (if the wheel is build to withstand this charge current) should improve the situation in terms of flexibility.

Otherwise, @MBIKER_SURFER, if you charge for 10h during the night and leave in the morning, this should IMHO not lead to such a significant over-degradation of the battery, as it leaves the battery only a couple of hours per day at 100% charge.

If @MBIKER_SURFER uses by now a 1.5A Charger that should be ~1.5A/12.8Ah = 0.11C charge. So the CC phase should take about 9 hours (from real 0% capacity). So depending on the start capacity the cells should be in average not at a too high voltage, but some 5A charge would reduce this times drasticly.

 

[Stoney]

Your charging is not the problem with your battery. In matter of fact the way you are charging is best for your battery. The slower the charge and the less time it sits at 100% (meaning 12hours or less before you ride is ok). By charging with a slow charger your cells don’t get heated as fast as well as you are giving the cells time to balance. If anything is wrong it is either ther cells themselves, the charger not charging and balancing properly, or/and cell degradation from the EUC AMP DRAW ITSELF - welcome to electric motorizations. 

The bottom line - you use your euc everyday and you use it to its capacity. Many riders here don’t use their euc like this and so don’t have 1st hand experience with a real life situation it’s mostly book smart (not trying to be offensive)

if you go to endlessphere.com forum and ask the same question and you give the specifics of usage the high amp draw and cycles you will realize that their is and should be degradation in real life usage. 

A would expect a 2yr high usage of any euc battery and at that point I would buy a new battery regardless or new ewheel. 

 

 

[Chriull]

1 hour ago, Stoney said:

Your charging is not the problem with your battery. In matter of fact the way you are charging is best for your battery. The slower the charge and the less time it sits at 100% (meaning 12hours or less before you ride is ok). By charging with a slow charger your cells don’t get heated as fast as well as you are giving the cells time to balance.

Do you have any sources for charge cycle vs. charging current? Especially in the range like here between 0.1C and 0.5C? I've found nothing regarding this on batteryuniversity.com - imho a great collection of li ion cell knowledge.

Just:

"Apply the ultra-fast charge only when necessary. A well-designed ultra-fast charger should have charge-time selection to give the user the option to choose the least stressful charge for the time allotted. Figure 2 compares the cycle life of a typical lithium-ion battery when charged and discharged at 1C, 2C and 3C rates. The longevity can further be prolonged by charging and discharging below 1C; 0.8C is the recommended rate."

at https://batteryuniversity.com/learn/article/ultra_fast_chargers

"The advised charge rate of an Energy Cell is between 0.5C and 1C; the complete charge time is about 2–3 hours. Manufacturers of these cells recommend charging at 0.8C or less to prolong battery life; however, most Power Cells can take a higher charge C-rate with little stress. Charge efficiency is about 99 percent and the cell remains cool during charge."

at https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

So, at least there is nothing mentioned of any advantages or disadvantages within the 0.1-0.5C range...

Also part time the time per day at full charge in regard to cell degradation. There is "just" the number that at 4.2V and 25°C there is a 20% capacity loss after a year. I'd strongly assume that 12h every day over a year will lead to 10% capacity loss. Although it's speculation to conclude from a continous state to some "part time" state?

 

Quote

...cell degradation from the EUC AMP DRAW ITSELF - welcome to electric motorizations. 

That's undiscussable imo one of the main points. Fortionately with the battery packs capacity growing and by this more cells in parallel the situation got better. But still the 4p cells will still be burdened with their max 10A continous discharge current. And maybe a bit above. So @MBIKER_SURFER "idea" to changing to some 1500Wh EUC will not only give him more capacity to drive his needed distance every day, but by the less burdened cells longer lifetime.

... And this 10 Amp max continours current specified for many of the used li ions in EUCs are still 2-3C discharge for them:

 

Figure 4 demonstrates capacity loss caused by the structural degradation of an older Li-ion when cycled at a 1C, 2C and 3C. The elevated capacity loss at higher C-rates may be lithium plating at the anode caused by rapid charging. [See BU-401a: Fast and Ultra-fast chargers]

 

Figure 4: Cycle performance of Li-ion with 1C, 2C and 3C charge and discharge. Moderate charge and discharge currents reduce structural degradation. This applies to most battery chemistries." from https://batteryuniversity.com/index.php/learn/article/bu_808b_what_causes_li_ion_to_die

And additional to this "overburden" - this ~10A for a battery cell is the average current, the EUC takes much higher currents "chopped by the PWM signal". I never have seen any articles about peak burdens for Li ions...

 

[Mono]

2 hours ago, Stoney said:

Many riders here don’t use their euc like this and so don’t have 1st hand experience with a real life situation it’s mostly book smart (not trying to be offensive)

Tell us more about your usage experience with EUCs! Several years? 20000 miles? More?

I don't think that any of us has even a tiny remote chance to become an expert on batteries by their own users experience. That claim is true for pretty much any expertise on knowledge that humanity has acquired in this world. Getting an expert takes some experience and lots and lots of educated critical reading or other ways to acquire knowledge from other sources. That just follows from the observation that finding things out by experience takes so much more time and resources than critical reading or listing.

[Stoney]

This is still a young sport and new tech. Those charts quite honestly don’t equate to real life. What euc does to the cells in it’s “fun” activity is not tested in the lab. As time passes like in ebikes - custom built and store bought for that matter you will SEE the real discharge cycles that it actually gets. Even if you charge to 80% and never go below 30% and only “top off” when absolutely necessary. You will never get the 700 cycles or 1500 cycles by being perfect! Your battery has a shelf life of 2yrs of heavy usage but usable for 3 or 4 but it has so much sag it’s not even worth riding. Which would be dangerous for EUC’s.

Right now people ride and upgrade w/n a year because improvements are happening so fast. And quite possibly those who understand what I am saying “sell after a year get the resale value and not have to worry about the danger and buy new again.”

Once this sport matures more. Getting the electronics and strength perimeters out the way - axles surges etc. Then there is going to be a strong need for battery replacement care. Because in this sport that is critical to safety. In ebikes it just means less power and cut outs and then you pedal or push. With euc it is not the same.

i know you said before that “this is not discussable” but watch or look into ebikes because they are the maturist form factor and a wealth of knowledge about real battery life. 

I have been 100% car free for 10yrs. And I have a daughter that has grown up on the back of my custom built ebikes. And it has been a blast, frustrating, and financially rewarding experience.

i hope I am not rubbing anyone the wrong way because I have not been so excited about something new in e transportation since ebikes so I am excited about being in this community and look forward to offering my experience when appropriate and right now I am “book smarting” this forum until I find out which wheel I want to begin this amazing journey!

but I will say this - it will be a new wheel or a wheel that is only a couple of months old...

[Stoney]

Mono

just saw your reply. I was typing when you posted. I think I stated my point to yours. Also, I average 1000 miles a month (for 10 yrs). When batteries become a serious need I believe that people will gravitate to independent offerings or start building their own but one great place I would turn to and we’ll repected in the community is

EM3EV.con he makes unbelievable batteries