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Charge Doctor for INMOTION

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Bram    49
3 minutes ago, KingSong69 said:

Hy Bram..

i also got a CD....

You have to know that even if you change nothing...there is an on off setting!

Only when the "1.00" amp is blinking before you start charge...it will work!

if "0.00" is blinking you are in the "autoshutmode" OFF setting.....

I didn't notice the blinking part when starting up but I'm 100% sure it shut off at 1A because 1. it said so on the CD (and the v8 wasn't being charged anymore) and 2. it shows the same in the log ;) EDIT: if you could send me a log file (or post a graph) I'd much appreciate that.  Nevermind, just noticed u don't own the v8 :P 

Edited by Bram
too quick to reply

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KingSong69    3,700

also:

the amps on the CD/charging going down at the end of charge...is normal!

the ampere goes down to about 0.15 then charge light goes to green! (when auto is off)!

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KingSong69    3,700
1 minute ago, Bram said:

I didn't notice the blinking part when starting up but I'm 100% sure it shut off at 1A because 1. it said so on the CD (and the v8 wasn't being charged anymore) and 2. it shows the same in the log ;) if you could send me a log file (or post a graph) I'd much appreciate that.

blinking is just shortly after plug in of charger...ok, then your app is just not exact

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Bram    49

So I got KST to work by reselecting the columns (vector type) in the data manager. In the second charge the Amps still fluctuate at the end, so I'm really hoping someone with a V8 and a charge doctor can post a screenshot if this is normal for this unit.

For experiments sake I slowly kept driving the v8 till 3% while driving and after standing still a bit it went up to 11% (according to the app). This time I also continued charging after the auto cutoff to check how much I could pack into my battery pack. Here are the graphs:

2nd charge.png

 

Some observations (assuming a real 480Wh battery):

1. in reality the v8 stops driving whilst there is still ~14% juice left in the battery

2. The autoshutdown function at 1A charges till ~94% battery

 

some conclusions:

So in order to maximize your battery you want to charge it to max 80-90%. Below graphs show the different auto shutdown lines, 80% green line, 85% orange line and 90% red line. Especially with my battery pack fluctuation a cutoff point based on voltage seems more reliable.

 

auto shutdown.png

 

I'm really interested in what you guys think. And I really hope someone can provide a different v8's charge information.

 

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FreeRide    145

Not sure what that noise is just before the charge should switch from constant current to constant voltage, but typically such things would be an indication of reaching that max power handling of the power supply/regulator. 

To measure the true capacity of the pack you would need to do a discharge test with an analyzer that is accurately calibrated. Unfortunately that's almost always lower than the estimate based on input power during charging. Seems you are probably aware of this.  

From what i've read so far the packs for EUCs are typically cut off much higher than 2.5-2.8V which means that the theoretical max energy of the pac could not be utilized. Some also seem to already not charge to 100% even without something like the Charge Doctor using it's own auto cut off.  This all gives a theoretical increase in the cycle count, because reach customer cycle is not really a full cycle and limiting the extremes is reported to increase the cycle count for some chemestries. 

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Bram    49
On 26-12-2016 at 3:00 PM, hobby16 said:

Whereas with voltage cutoff, you have more resolution in the threshold and can autocut at much lower level, eg 80% or even 70%.

  Cells 0% 30% 60% 70% 80% 90% 100%
Total discharge cycles* 1800-3600 1200-2400 950-1900 700-1400 500-1000 300-600

I'd love to extend my battery a lot by charging to 80-85%, however I think the current chargedoctor does not allow auto cutoff based on voltage levels, right? I've been looking at the menu and after that the website but so far I only see the option to change based on A.

If this is the case would it possible to fix this with a FW upgrade for the CD? Feels like I'm still missing out on saving a lot of battery life otherwise...

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HEC    1,184
23 minutes ago, Bram said:

I'd love to extend my battery a lot by charging to 80-85%, however I think the current chargedoctor does not allow auto cutoff based on voltage levels, right? I've been looking at the menu and after that the website but so far I only see the option to change based on A.

If this is the case would it possible to fix this with a FW upgrade for the CD? Feels like I'm still missing out on saving a lot of battery life otherwise...

CD from version 2.03 onwards allows both current and voltage cut-off. If you have older version it's unfortunately not possible to update FW on the device on-sita / by user.

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Bram    49

I do have 2.04, so that shouldn't be the issue. I can't seem to find the option though :( did I miss it on the instructions on the website? 

Found it: http://hobby16.neowp.fr/2016/11/07/charge-doctor-v2-firmware-v-2-03-2/

It would probably be helpfull to not have to search all the posts but have it available in the instructions section available from the top bar ;) (just trying to justify my ignorance, poor searching here :P)

Edited by Bram
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HEC    1,184
25 minutes ago, Bram said:

I do have 2.04, so that shouldn't be the issue. I can't seem to find the option though :( did I miss it on the instructions on the website? 

I think the voltage cut-off might be still missing from the website. From top of my head (as CD is at home):

Hold the reset button on CD and apply the power. Hold for about 5 s until the CD beeps and display starts to blink. Then by pushing briefly the reset button "scroll" trough options until you see the "dn A" / Current cut-off. Then by holding the reset button you can change from "dn A" / Current to "UP U" / Voltage for charging and "dn U" / Voltage for discharging, You'll indeed want the first one "UP U" / Voltage for charging option. Then press again shortly the reset to go to voltage selection and finally there by long press initiate the value change. You can either hold the button or press repeatedly to increase the value. I thing v2.04 have already increased cut-off voltage as v2.03 unfortunately can't be used with V8 (or any other 84V model EUC) as it's maximum cut-off voltage is below 80V. I hope I've remembered the steps correctly - basically follow the guide on the web and once you reach the point where it talks about "dn A" / Current you can flip it to voltage instead.

Edited by HEC
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Bram    49

Thanks HEC, I actually found the page with the instructions literally while you were typing your post. That's why I edited my previous post ;) 

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z3n    95

Hi @Bram, how did it go with your CD's voltage auto cut-off result? Did you set the threshold to 80.4V for 80% charges or any other numbers? Mind to share your threshold choice with us? Thanks! :cheers:

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Mono    1,288

@z3n, I have set the threshold to 81.5V and get a little under 80% battery level. 75V is roughly 30% battery level, 83V is about 90%.

Edited by Mono
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z3n    95
18 hours ago, Mono said:

I have set the threshold to 81.5V and get a little under 80% battery level. 75V is roughly 30% battery level, 83V is about 90%.

Thanks man, but why did you choose to set the threshold to 81.5V and got a little under 80% when to be on 80% would be our best aim? Do you think it is even better to get a little under 80% instead of right on 80% or even above? Kinda confused here now... :blink:

Edited by z3n
fingers act faster than brain

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Bram    49
2 hours ago, z3n said:

Thanks man, but why did you choose to set the threshold to 81.5V and got a little under 80% when to be on 80% would be our best aim? Do you think it is even better to get a little under 80% instead of right on 80% or even above? Kinda confused here now... :blink:

Hi Z3n, thanks for reminding me that I really needed to post that update. I managed to get the information on how to switch to a voltage level from this website: http://hobby16.neowp.fr/2016/11/07/charge-doctor-v2-firmware-v-2-03-2/

The trick is to change (in the adjustment mode) to "up V", you can then adjust the value to what you want and get the battery percentage to where you want it. The theory is that every 10% from full charge doubles the expected cycles, that might be why Mono charges to 80%. Personally I'd balance the charging % to your needs. I can use my wheel for commuting two days if I charge it to 85-90% without dropping below 20% (I'll update my review, but I'm not happy with the v8 under 20%). I'm still looking for the sweetspot for that on my CD, but the option to use that for cutting off the charge is a life safer. Indication for the levels can be deduced from the screenshot I posted earlier, but if you want a certain % let me know and I'll zoom in and look it up ;).

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Mono    1,288
On 11/01/2017 at 4:23 PM, z3n said:

Thanks man, but why did you choose to set the threshold to 81.5V and got a little under 80% when to be on 80% would be our best aim? Do you think it is even better to get a little under 80% instead of right on 80% or even above? Kinda confused here now... :blink:

When I did the research some time ago I documented that the optimal up-charge for longevity is between 3.9 and 4V for the single cell, that is between 78 and 80V for the pack. This value might depend on the specific cells, but that's all information I have for now. The other part of the equation I don't quite figured yet is whether this is the voltage measured during or after charging. Also, 80% is probably a rather arbitrary number in the display. For sure, 0% on this scale doesn't mean the battery is even close to be empty. 

In any case, if I would only optimise for battery life I would not go above 80V which probably allows for at least 2000 cycles (2000x473Wh). On the other hand, if 82V gives me 1000 instead of 500 cycles, that would allow for about 30,000km with which I can live very well.

Edited by Mono
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rdalcanto    138

I used the CD (charge doctor) today for the first time with my V8 and the 2.5A fast charger.  I set the cut off for 2.0A.  Between the time the CD showed 83V and the 2.0A cutoff, 58 (edit - Wh, not Amps) went in.  Assuming that the batteries were still not fully charged at the 2.0A cutoff, then a 83V cutoff (when using the fast charger) would be less than 88% charge based on a 480WH battery.

Edited by rdalcanto
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z3n    95

Thank you guys @Bram@Mono@rdalcanto for your useful info. I will go with @Mono's setting for now since my 80% charged V8 is more than enough for my daily rides. Charge it at night before sleeping and it would be all ready again in the morning. Really simple and free of hustle.

Thank you @hobby16 for this great product! :thumbup:

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Mono    1,288
11 hours ago, z3n said:

Charge it at night before sleeping and it would be all ready again in the morning. Really simple and free of hustle.

Kind-of forgot to add: there are several ways to wear down a battery. Full cycling is one, another one is to keep the battery at full charge in particular combined with higher temperature (i.e. > 20ºC). The optimal storing voltage is around 71.5V (a little under 3.6V, about 40%). This suggests to preferably charge before departure rather than after arrival. I charge, if needed, to around 72V upon arrival before to store the horse away and then to 81.5V before departure. This of course entails the risk to forget charging in the morning with the unfortunate surprise when in a hurry to leave. To prevent this I formed the habit to give juice to my horse first thing in the morning right before I have the first coffee myself. Isn't this anyway the appropriate treatment for the best horse in the barn?

Edited by Mono
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Mono    1,288
17 hours ago, rdalcanto said:

I used the CD (charge doctor) today for the first time with my V8 and the 2.5A fast charger.  I set the cut off for 2.0A.  Between the time the CD showed 83V and the 2.0A cutoff, 58 Amps went in.

Do you mean 0.058 Ah? Which is 58 Milliampere hours and would be 0.058Ah * 84V = 4.9Wh (a short touch on the button which toggles between Ah and Wh and cut-off-status should clarify). This seems more likely to me, as I am almost certain that one can not put 58Wh additional charge into the battery when starting from 83V. Even assuming that the battery voltage drops to 82V as the true value when the charger is unplugged, I don't think more than 50Wh of charge can be added. 

Quote

Assuming that the batteries were still not fully charged at the 2.0A cutoff, then a 83V cutoff (when using the fast charger) would be less than 88% charge based on a 480WH battery.

Consider that at both ends of the Wh-vs-V curves the stored Wh/V gets smaller. I would roughly estimate that we can store maybe 15Wh more from 83V to the max of 84V. This is a little hard to estimate via the CD, because there is a constant current flow, even when the battery is fully full, which inflates the shown values in the end. Below 83V, the charge is according to my records probably a little above 25Wh/V.

A typical discharge graph:

http://batteryuniversity.com/learn/article/discharge_characteristics_li

Edited by Mono

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rdalcanto    138
41 minutes ago, Mono said:

Do you mean 0.058 Ah? Which is 58 Milliampere hours and would be 0.058Ah * 84V = 4.9Wh (a short touch on the button which toggles between Ah and Wh and cut-off-status should clarify). This seems more likely to me, as I am almost certain that one can not put 58Wh additional charge into the battery when starting from 83V.

Consider that at both ends of the Wh-vs-V curves the stored Wh/V gets smaller. I would roughly estimate that we can store maybe 15Wh more from 83V to the max of 84V. This is a little hard to estimate via the CD, because there is a constant current flow, even when the battery is fully full, which inflates the shown values in the end. Below 83V, the charge is according to my records probably a little above 25Wh/V.

A typical discharge graph:

http://batteryuniversity.com/learn/article/discharge_characteristics_li

Sorry, I meant 58Wh.  According to the CD, from around 35% charge according to the Inmotion App, to 2.0A cutoff, 280Wh total went in, which is about right, since 280Wh represents 58% of the 480Wh capacity, and I tried to not charge to full.  If I ride again today, I'll double check my numbers.

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rdalcanto    138

More Numbers.  

Plugged in to charge at 75.5V (only number I'm not sure about).  At 79V, 64 Wh had gone in.  Then it was about 25Wh for each volt increase.  80V - 88Wh.  81V - 115, 82V - 142, 83V - 166, 84V  - 187.  At the 2.0A charge rate cutoff that I set, total Wh in 221.  So from 83V to cutoff was 55Wh, or 11.5% of battery capacity.  So if you want to use the fast charger, and charge to under 90%, cutoff at 83V.  One of these times I'll disable the cutoff and see how many Wh it will hold from 83V to 100% charge to get a more accurate feel for what percent charge the 2.0A cutoff and 83V cutoffs actually represent.  2.0A cutoff showed 84.9V

Edited by rdalcanto
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Mono    1,288

I am sorry, I think I mistakenly equated battery voltage with the voltage displayed by CD while charging. The latter is, I believe, about 1V higher unless we get close to 84V. What I didn't expect: this depends decisively on the charge current. I just checked charging with 1.6A against 3.2A and this makes a difference of 1.1V in the display of the CD (I observed 74.5 vs 75.6V).

That is, a good approximation of battery voltage is probably displayed voltage minus 0.7 times displayed charge current.

EDIT: there is apparently an additional voltage drop of about 0.6V due to the built-in diode. That is, we may have voltage_displayed - 0.7 x current_displayed x V/A - 0.6V as estimate for (disconnected) battery voltage.

Edited by Mono
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rdalcanto    138
3 hours ago, Mono said:

I am sorry, I think I mistakenly equated battery voltage with the voltage displayed by CD while charging. The latter is, I believe, about 1V higher unless we get close to 84V. What I didn't expect: this depends decisively on the charge current. I just checked charging with 1.6A against 3.2A and oups, this makes a difference of 1.1V in the display of the CD (I observed 74.5 vs 75.6V).

I agree.  That is why I made sure to note that my numbers are with the new 2.5A fast charger that Jason provides.

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Maximus    331

Are you guys using the inmotion app, Darkness Bot (or other) to determine the percentage that the battery is being charged?  

I just changed the Charge Doctor auto-cut from 1.0A to 83V to see if I can get it to stop closer to 90%.  Seemed like my CD was charging closer to 97% with the auto-cut set to the default 1.0A. I'll report back this afternoon to see if that change does the trick, but would be curious if there are some known problems with the apps showing incorrect battery percent and if so, what others are using to determine if there CD is doing what it is supposed to do (i.e. restrict charging to 80 or 90%...). 

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