MSX still not happy with battery ☹️

[stephen]

Mmmm similar , wish mine said 100%😁

[Mike Sacristan]

1600wh 84v MSX purchased from Ali in the beginning of November 2018 and received in January 2019.

If I leave mine on the charger I can go higher than 95-96% but I rarely bother since I get 1km per % at around 15C.
I rarely go over 35km/h and tend to hover at 29km/h.
I weigh 64kg and +2~3kg with clothes and my tiny backpack.

After a 5km ride

After 16km

After 26km

And after getting home

Ad now the battery is at 73%.

13C today.

[Chriull]

9 hours ago, stephen said:

So someone mentioned use darknessbot its more accurate ,, anyway full over night charge , got screen of darkness bot and wheelog .. Wheellog is usually 96% yay i got 97%,, voltage both same nearly😁 darknessbot 92%🤔

They just use different formulas - they all start with the Voltage value they get from the wheel.

With 82V (4.1V per cell) a li ion battery pack has some 80-90% charge

Unfortionately the voltage measurement can be off...

[stephen]

On 4/30/2019 at 8:41 PM, Marty Backe said:

A simple experiment (for me anyway) is this:

• Open the panel and disconnect one of the batteries and charge the wheel fully. What do you see?
• Now disconnect that fully charged battery and connect the other one. Charge the wheel. What do you see?

If you have a problem with the batteries, it'll most likely be in only one of the packs. I can't imagine two battery packs having defective cells.

If you do the above simple experiment, before connecting the two batteries you'll have to drain one of them enough so that the voltage reads the same on both packs.

@Marty BackeBacke I'm going to do this today , 

So i simply unplug one of the batteries and charge it up see what voltage i get and same with the other, when I'm plugging the batterys in and out will it spark because the capacitor is full or should it be ok , if both batteries have same voltage I'm ok to plug both in . If different i just simply go for a ride on one battery and drain the fullest battery down to the lowest one (the faulty one if it is) 

And,,,,,If i end up living with a dead cell would that be ok or would it be not healthy to the other batteries for balancing etc? But then again if it is that Ian should sort it

Thanks 

Edited May 3, 2019 by stephen

[Marty Backe]

3 hours ago, stephen said:

@Marty BackeBacke I'm going to do this today , 

So i simply unplug one of the batteries and charge it up see what voltage i get and same with the other, when I'm plugging the batterys in and out will it spark because the capacitor is full or should it be ok , if both batteries have same voltage I'm ok to plug both in . If different i just simply go for a ride on one battery and drain the fullest battery down to the lowest one (the faulty one if it is) 

And,,,,,If i end up living with a dead cell would that be ok or would it be not healthy to the other batteries for balancing etc? But then again if it is that Ian should sort it

Thanks 

I always anticipate the spark. I think if the capacitors haven't been discharged you may not get much of a spark. Whenever I've worked on my wheels where I've disconnected the battery, I always turn the wheel back on to discharge the capacitors so I can't shock myself by accident. This causes there to be a large voltage differential which causes the spark. If the capacitors never get discharged then the spark should be minimized.

And remember the best practice: Always disconnect the control board battery connector before any other connectors are disconnected, and when reconnecting things, always reconnect the control board battery connector last.

[Scully]

Interesting post.
I could swear the range on my MSX is low - but I put it down to high speed riding. Yesterday I rode to work (10 miles, average speed around 20mph) and was down to 60/70% battery.

[Olav]

13 minutes ago, Scully said:

Interesting post.
I could swear the range on my MSX is low - but I put it down to high speed riding. Yesterday I rode to work (10 miles, average speed around 20mph) and was down to 60/70% battery.

According to your signature you have a Msuper V3 S+ with the same size battery, have you compared against that?

[Scully]

1 minute ago, Olav said:

According to your signature you have a Msuper V3 S+ with the same size battery, have you compared against that?

I sold that... need to update my signature.
I put the battery loss down to riding faster on the MSX (until I saw this thread).

I did the UK ride out the other weekend - then tried to go for a ride a couple of days later and was shocked how low the battery was.... that's whats got me wondering.

[Olav]

2 minutes ago, Scully said:

I sold that... need to update my signature.
I put the battery loss down to riding faster on the MSX (until I saw this thread).

I did the UK ride out the other weekend - then tried to go for a ride a couple of days later and was shocked how low the battery was.... that's whats got me wondering.

If you were at the Bristol-meet then you probably know of others nearby that have an MSX. Or possibly you could ask Ian for an advise (Mitcheldean seems to be not too far away ).
Do you get 100% battery in the app? I assume you started with full battery before riding to work.

[Scully]

I downloaded darkenss bot, then went out and did a quick circuit - the readings are all over the place...

 

 

I found the battery drop - just like yours... then after the ride it wa showing 75% (when stationary) - I was worried this was low, so went back to the wheel 5 mins later and it's showing 88%
The main gotway app also shows 90% after the ride is done.

I guess I'll have to do a real world range test and see how I get on.

[stephen]

5 hours ago, Scully said:

Interesting post.
I could swear the range on my MSX is low - but I put it down to high speed riding. Yesterday I rode to work (10 miles, average speed around 20mph) and was down to 60/70% battery.

I've been doing some tests with my charger it wasn't outputting full voltage , I've adjusted it to 84v and done a couple of range tests and it's better it still needs fine tuning , I'll report back with my outcome but at least I'm getting 84v from the charge port with multimeters 😊 , you can adjust your standard gotway charger if you wanted to it needed . I've just been out to finish second part of my range test,,38 miles and 19% left ,,

day one of my test i thought I'd run the battery right down to 0% and got 47 miles , both these test i just did normal riding ,mix of fast and slow anywhere from 10-25mph , I'm 95kg+ with my gear on . Hills and flat conditions, mainly road riding

 

Edited May 5, 2019 by stephen

[stephen]

I'm still doing more tests ,i don't think my batteries was balanced properly due to charger been out . I'm happier with the range so far I'm sure ive gained 5-10 miles . It's still cold in the uk so warmer weather should be kinder in the batteries, now to balance my batteries again on slow charge that's why I've been running then right down , once happy i don't have to charge fully unless needed, but i probly will anyway who am i kidding

As people might know on this forum I've never had 100% on my app or 84v on my batteries 

😀 don't trust the apps voltage

Edited May 5, 2019 by stephen

[Marty Backe]

Can you try 90-volts and let us know what kind of range you get? 

[stephen]

2 minutes ago, Marty Backe said:

Can you try 90-volts and let us know what kind of range you get? 

Lol 😃

marty I've been very careful with my testing and had some help with someone who knows allot about chargers and batteries , you know how this has been doing my head in and always thought something wasn't right .i don't think my batteries have never been balanced right I'm happy with the results so far ,, i won't be pushing any voltage i don't want to blow up I've monitored everything and its been painfully slow at times , I'm charging and balancing again 3rd time just to triple check 😊 

[Bob Eisenman]

10 hours ago, stephen said:

you know how this has been doing my head in

With all respect due to the various parameters made available through the use of WheelLog and the people who make use of the data in some way.......much of the intellectual distress about battery charge state can be avoided by just using the Gotway app to perceive ride parameters (speed, battery%, range).

Which reminds me.....I've always thought the 40% (+ or - )5% battery level on Monster had the most prolonged range....but I never tried to measure a specific number to the range.😅🙄

[Chriull]

12 hours ago, stephen said:

As people might know on this forum I've never had 100% on my app or 84v on my batteries 

...

😀 don't trust the apps voltage

Unfortionately its not the apps fault - it just shows the voltage reported (wrongly) from the wheel.

82.3V instead of 84V is really way off... ... But "just" 2% of relative error...

So for the lower limit of ?3.3V? per cell = 20x3.3=66V measured by the board your battery still has some 67,4V... 67,4/20=3,37V per cell in reality.  With 3.0V a cell has still 5% charge left - so you "loose" some range here with the wheel stopping at 3.37V instead of 3.3V.

12 hours ago, stephen said:

I'm still doing more tests ,i don't think my batteries was balanced properly due to charger been out . I'm happier with the range so far I'm sure ive gained 5-10 miles . It's still cold in the uk so warmer weather should be kinder in the batteries, now to balance my batteries again on slow charge that's why I've been running then right down , once happy i don't have to charge fully unless needed, but i probly will anyway who am i kidding

The gained miles result from adjusting your charger?!

New battery packs with their cells are balanced and stay this for quite some time. If the cells used were already so badly mismatched that they drift apart from the beginning none of the nowadays in EUCs used balancer can correct this!

From a schematic/data sheets of common chinese BMS mostly the overvoltage threshold for single cells is about ~4,25-4,27V (charger input shutoff) and ~4,2V balancing threshold, were some 50-100 Ohms are put in parallel to these cells. So some 4.2V/(50...100 Ohm)~40..80mA of charging current are bypassed, mostly in the constant voltage phase of charging.

With a "normal" 1C charging it takes ~1 hour for the constant current phase (up to ~85% charge) and the ~2 hours of constant voltage phase to charge the remaining 15%. In this ~2 hours CV most of the balancing occurs.

If you have a 1600Wh MSX that'll mean you have a 20s6p configuration with 3500mAh li ion cells. 1C charge would be in this case 6x3.5=21A. Charging with 2.5A would be a 0.12C charge - so the CC phase takes 1/0.12=~8 hours, the CV phase ~17 hours.

At the end of the CV phase at around 2% C chargers normaly cut off charging. Is imho something around ?100-200mA? with the standard stock chargers - can be adjusted, too.

One way to check if the batteries are badly balanced is to look if the charging is cut off by the BMS prematurely - then one of the cells has reached the ~4.25-4.27V. Leaving the other 19 cells at around (84-4.27)V/19~4.2V in average...

Edited May 6, 2019 by Chriull

[Chriull]

14 hours ago, Scully said:

I found the battery drop - just like yours... then after the ride it wa showing 75% (when stationary) - I was worried this was low, so went back to the wheel 5 mins later and it's showing 88%

That's normal behaviour of li ion cells. Batteryuniversity.com recommends 1 hour resting time for using the cell voltage to calculate charge 

14 hours ago, Scully said:

The main gotway app also shows 90% after the ride is done.

The apps just have a upper threshold for 100% (somewhere ~4.1-4.15V) and a lower threshold at ~3.3V for 0% charge. Inbetween the values are calculated by linear approximation.

Just afaik in wheellog was the chance once si that this calculation is not anymore strictly linear, as li ion cells hold relatively more capacity per voltage difference at the high voltage range compared to the lower end.

But anyhow - charge percent shown by an app are just numbers one can get used to, but they are not to be taken as absolute truth.

[Scully]

I've got both - a standard gotway charger and a fastcharger - but, as above my wheellog is reading 64v (although I couldn't tell you which charger I most recently used). 

I'm pretty sure my MSX is from the same batch as yours.......

[stephen]

7 hours ago, Scully said:

I've got both - a standard gotway charger and a fastcharger - but, as above my wheellog is reading 64v (although I couldn't tell you which charger I most recently used). 

I'm pretty sure my MSX is from the same batch as yours.......

You have to change wheellog to 84v in settings

Edited May 6, 2019 by stephen

[stephen]

11 hours ago, Chriull said:

Unfortionately its not the apps fault - it just shows the voltage reported (wrongly) from the wheel.

82.3V instead of 84V is really way off... ... But "just" 2% of relative error...

So for the lower limit of ?3.3V? per cell = 20x3.3=66V measured by the board your battery still has some 67,4V... 67,4/20=3,37V per cell in reality.  With 3.0V a cell has still 5% charge left - so you "loose" some range here with the wheel stopping at 3.37V instead of 3.3V.

The gained miles result from adjusting your charger?!

New battery packs with their cells are balanced and stay this for quite some time. If the cells used were already so badly mismatched that they drift apart from the beginning none of the nowadays in EUCs used balancer can correct this!

From a schematic/data sheets of common chinese BMS mostly the overvoltage threshold for single cells is about ~4,25-4,27V (charger input shutoff) and ~4,2V balancing threshold, were some 50-100 Ohms are put in parallel to these cells. So some 4.2V/(50...100 Ohm)~40..80mA of charging current are bypassed, mostly in the constant voltage phase of charging.

With a "normal" 1C charging it takes ~1 hour for the constant current phase (up to ~85% charge) and the ~2 hours of constant voltage phase to charge the remaining 15%. In this ~2 hours CV most of the balancing occurs.

If you have a 1600Wh MSX that'll mean you have a 20s6p configuration with 3500mAh li ion cells. 1C charge would be in this case 6x3.5=21A. Charging with 2.5A would be a 0.12C charge - so the CC phase takes 1/0.12=~8 hours, the CV phase ~17 hours.

At the end of the CV phase at around 2% C chargers normaly cut off charging. Is imho something around ?100-200mA? with the standard stock chargers - can be adjusted, too.

One way to check if the batteries are badly balanced is to look if the charging is cut off by the BMS prematurely - then one of the cells has reached the ~4.25-4.27V. Leaving the other 19 cells at around (84-4.27)V/19~4.2V in average...

All i know is my charge doctor reads 84v charger reads 84v and input socket on my msx reads 84v when full all measured with multimeter , before this my voltages were way out , my charger kicks in and balances perfect now .i don't care to much about values in wheel log I've learnt that they are out , but i did care that I've wasn't getting the right reading from my mutimeter and charge doctor .. Now everything's in sync and happy with how long my range is 😊

 

Edited May 6, 2019 by stephen

[Chriull]

3 hours ago, stephen said:

All i know is my charge doctor reads 84v charger reads 84v and input socket on my msx reads 84v when full all measured with multimeter , before this my voltages were way out , my charger kicks in and balances perfect now .i don't care to much about values in wheel log I've learnt that they are out , but i did care that I've wasn't getting the right reading from my mutimeter and charge doctor .. Now everything's in sync and happy with how long my range is 😊

Yes - that's all great now. Just the apps just showing the voltage measured and reported by the mainboard is still off. And nothing can be done against this but changing the mb. But changing does not give any security that anything gets better :(. The mbs are not calibrated...

So you loose capacity of the "low end". That's better, because that has less influence - li ion cells have less capacity on the low end than on the high end.

So this is the optimum you can achive without calibrating (imho not possible with mb's) or exchanging the mb...

Edited May 6, 2019 by Chriull

[stephen]

I love my msx I'm happy with it now , i wouldn't change the mb , you get to know your wheel and what it can do and trust it some what, 

If it's out of voltage maybe it's a bit ssafer at the lower end when it tilts back and demands a bit of power .

I should of measured the voltage when i ran it to 0% battery , what should the voltage be at then just in case i do it again 😊

Edited May 6, 2019 by stephen

[Bob Eisenman]

On 4/30/2019 at 3:41 PM, Marty Backe said:

If you have a problem with the batteries, it'll most likely be in only one of the packs. I can't imagine two battery packs having defective cells.

If you do the above simple experiment, before connecting the two batteries you'll have to drain one of them enough so that the voltage reads the same on both packs.

So.....yesterday I decided to isolate the battery pack (1 of 2) on Monster that was not  charging to 100%. It was the left (non MB side) battery. After over depleting the charge on the good battery I added a small amount of charge until it was within about 0.5 volt of the other battery. With the motor power connector disconnected the two batteries were first connected in the parallel harness (without a spark) and then the the motor connector was reconnected without a spark. The MB was discharged before the reconnection process by pressing the power button after disconnecting the motor connector.

REASSEMBLED DUAL BATTERY

1_matched charge level (+ or - 0.5 volt)

    (77.68 volts/71%)

for both batteries😁

 

Edited May 7, 2019 by Bob Eisenman

[Bob Eisenman]

2 hours ago, Bob Eisenman said:

So.....yesterday I decided to isolate the battery pack (1 of 2) on Monster that was not  charging to 100%.

Here are my charging test results for 1600 Wh Monster:

Test charge L / R batteries:

 

LEFT SIDE BATTERY (NON-MB SIDE)

1_Charge (left only) non-motor side

(charger short pulse red with long green light)

 

2_Initial voltage:         (79.45 volt/82%)

                                    (77.98 volt/72%)

3_charge 30 minutes (78.53 volt/76%)

4_stop recharge attempt - no significant change

5_after sitting 1+ hours (77.73 volt/71%)

 

************

 

RIGHT SIDE BATTERY (MB-SIDE)

1_Charge (right only) MB side

(Constant red charger led)

 

2_initial voltage:  (78.46 volt/75%)

3_charge 10 min (80.19 volt/86%)

   charge 20 min (80.85 volt/90%)

   charge 30 min (81.31 volt/93%)

   charge 40 min (81.78 volt/96%)

   charge 50 min (82.08 volt/98%)

   charge 60 min (82.46 volt/100%) red led

   charge 70 min (82.68 volt/100%) red led

   charge 80 min (82.81 volt/100%) red led 

   charge 90 min (82.89 volt/100%) red led

[Chriull]

43 minutes ago, Bob Eisenman said:

LEFT SIDE BATTERY (NON-MB SIDE)

1_Charge (left only) non-motor side

(charger short pulse red with long green light)

 

2_Initial voltage:         (79.45 volt/82%)

                                    (77.98 volt/72%)

3_charge 30 minutes (78.53 volt/76%)

4_stop recharge attempt - no significant change

5_after sitting 1+ hours (77.73 volt/71%)

That looks like very dead, indeed.

And it stresses the right battery, too - so a quick replacement is recommendable.