500W/8.5A Z10 Fast Charger

[Rotciv]

In pursuit of more ride times with my Z10, I need a fast charger. Purchased a 10A Wate charger but discovered that the Z10 limits the charging current to 9A. This is to protect the connectors and wires from melting; kudos Ninebot engineers 👍👍

Since the charger has an internal current adjustment potentiometer, I dialed it in to limit the current to 8.5A. 

Fast charging at 500W

Balancing is handled by the BMS. Noticed how it’s only charging at 3A as the battery pack becomes fully charged.

Fast charging can put a lot of stress on the batteries. I would not recommend fast charging on a daily basis. 

[Chriull]

14 hours ago, Rotciv said:

Fast charging can put a lot of stress on the batteries. I would not recommend fast charging on a daily basis

How is the cell configuration and what cells are used?

Imho 6 3Ah in parallel? Then 8,5A are 0,47C and a nice normal recommended charge below 0.5C. Just for ?some Panasonic? cells the manufacturer recommends max charging of 0.4C.

If so you maybe could adjust you charger down to 7.2A to meet this requirement and everything would fine again.

For balancing there should be no difference, since this happens mainly in the CV phase which is not affected by the higher current ability of the charger. The CV phase should take about the same time, no matter if its a 1.5 or 8.5A charger. Maybe even a bit longer if one charges with more current...

[Rotciv]

The pack is 14s6p of LG MG1 which has a max charging current of 1.0C. 

My primary purpose for this charger is to top off when I’m on extended ride since my battery pack is degraded. I still use the stock charger for balancing at home. 

Next project is probably replacing the cells to LG MJ1

[Planemo]

9 hours ago, Rotciv said:

The pack is 14s6p of LG MG1 which has a max charging current of 1.0C. 

My primary purpose for this charger is to top off when I’m on extended ride since my battery pack is degraded. I still use the stock charger for balancing at home. 

Next project is probably replacing the cells to LG MJ1

I thought the Z10 used LG MH1?

[Rotciv]

2 hours ago, Planemo said:

I thought the Z10 used LG MH1?

Good catch! 3200mAh MHI

[Planemo]

Yep, but not sure it really helps you...they are 0.5c charging so less than you thought....MJ1 are 0.5c too....

Edit: Sorry, I just realised you are looking at max charging current, not normal charge current. So yes, both are 1.0max. Don't think I would want to do many charges at that though!

If I don't end up with a new Z10, I will probably rebuild my Z6 pack next year to run 84x 3500mah MJ1's to give 1088wh. If the rebuild shop is prepared to cram more cells in there I will. I know the crazy Russians did to make 1410Wh.

Edited May 26, 2019 by Planemo

[Rotciv]

27 minutes ago, Planemo said:

If I don't end up with a new Z10, I will probably rebuild my Z6 pack next year to run 84x 3500mah MJ1's to give 1088wh. If the rebuild shop is prepared to cram more cells in there I will. I know the crazy Russians did to make 1410Wh.

Any link to the Russians making battery packs for the Ninebot Z? I wonder if the cells can be oriented vertically when the wheel is laying on its side and use heat shrink wrap instead of the plastic enclosure.

[Planemo]

 

[Rotciv]

So after a week of testing different methods of fast charging my Z10, here are my observations:

• The BMS has thermal cutoff, letting it draw a lot of power (W) and it will get too hot and will cutoff charging
• At 500W/8.5A I can charge for about 30 minutes before cutoff
• At 470W/8A ~1 hour before cutoff
• At 440W/7.5A it will fully charge and balance the pack
• A pack that was used to ride ~30 miles can be charged until CV phase in less than 2 hours

Since I usually have several hours between long rides, I've decided to stick with 440W/7.5A charging. Luckily, my smaller Wate 5A charger is also adjustable and I was able to push it to 7.5A. I might be putting more work on the the transistors, but they are not even reaching 50°C. When I get a chance, I'll find out exactly what model transistors they're using. I've been using the 5A charger at 7.5A for several days without issues.

Size comparison between the 10A, 5A, and standard 2A Ninebot charger:

Potentiometer to adjust the 5A charger to output 7.5A during CC phase:

Here's a pack that was used for 27 miles, start of charging until CV phase is 1:25

[pollytronman]

On 6/3/2019 at 4:15 AM, Rotciv said:

So after a week of testing different methods of fast charging my Z10, here are my observations:

• The BMS has thermal cutoff, letting it draw a lot of power (W) and it will get too hot and will cutoff charging
• At 500W/8.5A I can charge for about 30 minutes before cutoff
• At 470W/8A ~1 hour before cutoff
• At 440W/7.5A it will fully charge and balance the pack
• A pack that was used to ride ~30 miles can be charged until CV phase in less than 2 hours

Since I usually have several hours between long rides, I've decided to stick with 440W/7.5A charging. Luckily, my smaller Wate 5A charger is also adjustable and I was able to push it to 7.5A. I might be putting more work on the the transistors, but they are not even reaching 50°C. When I get a chance, I'll find out exactly what model transistors they're using. I've been using the 5A charger at 7.5A for several days without issues.

Size comparison between the 10A, 5A, and standard 2A Ninebot charger:

Potentiometer to adjust the 5A charger to output 7.5A during CC phase:

Here's a pack that was used for 27 miles, start of charging until CV phase is 1:25

 

 

Hi Rotciv, I'm about to buy a Yzpower 58,8V 6A charger for my Z10. Do you think it will be safe a 6A charging? If I understand correctly you are charging at 7.5A without problem. I'm worried about the section/diameter of the internal cables. Don't you think those are a bit too thin for that amperage?

I would use the charger on extended routes from tiem to time. I usually charge with original charger at 2A overnight.

The charger I have in mind: https://es.aliexpress.com/item/32814788160.html?spm=a219c.12010612.8148356.6.335d2aaedDOhOI

 

 

Edited August 13, 2019 by pollytronman
sp

[Rotciv]

2 hours ago, pollytronman said:

Hi Rotciv, I'm about to buy a Yzpower 58,8V 6A charger for my Z10. Do you think it will be safe a 6A charging? If I understand correctly you are charging at 7.5A without problem. I'm worried about the section/diameter of the internal cables. Don't you think those are a bit too thin for that amperage?

I would use the charger on extended routes from tiem to time. I usually charge with original charger at 2A overnight.

The charger I have in mind: https://es.aliexpress.com/item/32814788160.html?spm=a219c.12010612.8148356.6.335d2aaedDOhOI

 

 

7.5A is borderline dangerous, it will need constant monitoring. When charging at that current, I would suggest removing the battery pack and charge it outside in case you get a thermal runaway and the battery pack starts a fire. You don’t want to lose your Z10 to a fire.

I’ve been charging at 6A regularly without any issues. At 6A, there is minimal heating on the internal wires.

Find a charger that allows you to trim the output voltage. The BMS will cutoff charging when the battery pack goes above 58.7v, probably causing some cells to have less charge than others. 

My daily charger is the 5A version of this one, adjusted to output 6A and the voltage output trimmed to 58.67v.

Order the charger with GX16-3 connector and get the male connector from ElecBee.

The display meter I used above is DROK 200139US from Amazon. The meter is useful to monitor the charging voltage and current. It will also show you power and total Wh.

[pollytronman]

12 hours ago, Rotciv said:

7.5A is borderline dangerous, it will need constant monitoring. When charging at that current, I would suggest removing the battery pack and charge it outside in case you get a thermal runaway and the battery pack starts a fire. You don’t want to lose your Z10 to a fire.

I’ve been charging at 6A regularly without any issues. At 6A, there is minimal heating on the internal wires.

Find a charger that allows you to trim the output voltage. The BMS will cutoff charging when the battery pack goes above 58.7v, probably causing some cells to have less charge than others. 

My daily charger is the 5A version of this one, adjusted to output 6A and the voltage output trimmed to 58.67v.

Order the charger with GX16-3 connector and get the male connector from ElecBee.

The display meter I used above is DROK 200139US from Amazon. The meter is useful to monitor the charging voltage and current. It will also show you power and total Wh.

Thanks for your advice Rotciv, so you recommend the Wate 6A over the Yzpower 6A? (I don't know how to trim the voltage, my electric knowledge is limited, I could defend myself though with some directions)

Thanks again

[Rotciv]

18 minutes ago, pollytronman said:

Thanks for your advice Rotciv, so you recommend the Wate 6A over the Yzpower 6A? (I don't know how to trim the voltage, my electric knowledge is limited, I could defend myself though with some directions)

Thanks again

No problem! I’m familiar with the Wate chargers and know how to adjust the current and trim the voltage. 

I’ll update my post on how to adjust the current and trim the voltage on the 5A Wate charger when I get home. 

[pollytronman]

Bought the material from aliexpress. Waiting for it to arrive.

I measured volts from original Z10 charger and I read 58.5V

[Rotciv]

50 minutes ago, pollytronman said:

Bought the material from aliexpress. Waiting for it to arrive.

I measured volts from original Z10 charger and I read 58.5V

When you get the charger, remove the top cover by removing the two top screws on both sides. Remove the two bottom screws on the output side to remove the end plate. 

You should now have easy access to trim the output voltage. If the potentiometer is covered with silicone, carefully remove to expose the adjustment screw. With the charger turned on but not connected to your wheel, trim the voltage to match the stock charger.  I would suggest leaving it on for a few minutes to stabilize the voltage before trimming.

[smallexis]

My solution is to put an external plug directly linked to the power circuit (of both batteries) that allow me to load at 12,9A without cutoff.

And this external plug allow me to extend my range with an external battery (DIY of course)

[pollytronman]

On 8/19/2019 at 10:51 AM, smallexis said:

My solution is to put an external plug directly linked to the power circuit (of both batteries) that allow me to load at 12,9A without cutoff.

And this external plug allow me to extend my range with an external battery (DIY of course)

This is level pro of battery modifications

[houseofjob]

On 8/18/2019 at 1:01 PM, Rotciv said:

@Rotciv out of curiosity, what is the 2nd trim pot beneath the Current pot? Thx.

Edited August 21, 2019 by houseofjob

[Rotciv]

7 minutes ago, houseofjob said:

@Rotciv out of curiosity, what is the 2nd trim pot beneath the Current pot? Thx.

It sets a current threshold for when the charging current falls below the threshold, the charger will turn off the fan and turn on the green led to indicate that the battery is fully charged.

It should be set to around 10mA, but the factory setting is acceptable.

[houseofjob]

8 minutes ago, Rotciv said:

It sets a current threshold for when the charging current falls below the threshold, the charger will turn off the fan and turn on the green led to indicate that the battery is fully charged.

It should be set to around 10mA, but the factory setting is acceptable.

Ah, ok, thanks!

I accidentally messed with this not knowing on my old eWheels 67V 5A charger, trying to set adjust the voltage. So you just multimeter that potentiometer for 10mA while adjusting? Thanks!

[Rotciv]

1 hour ago, houseofjob said:

Ah, ok, thanks!

I accidentally messed with this not knowing on my old eWheels 67V 5A charger, trying to set adjust the voltage. So you just multimeter that potentiometer for 10mA while adjusting? Thanks!

You need to put a meter between the wheel and the charger to measure the charging current.

A fully charged wheel should not be drawing more than 10mA. Use the charger on a fully charged wheel and adjust the potentiometer until the fan shuts off and you get the green led.

I don’t exactly remember which direction you turn the pot, but it’s multi-turn with clutch at the end. You won’t damage it by overturning. I would suggest marking your starting position and counting the turns. 

[houseofjob]

16 minutes ago, Rotciv said:

You need to put a meter between the wheel and the charger to measure the charging current.

A fully charged wheel should not be drawing more than 10mA. Use the charger on a fully charged wheel and adjust the potentiometer until the fan shuts off and you get the green led.

I don’t exactly remember which direction you turn the pot, but it’s multi-turn with clutch at the end. You won’t damage it by overturning. I would suggest marking your starting position and counting the turns. 

Awesome, thanks man!

Out of curiosity, do you know as well how to build chargers? Are you an EE?

[Rotciv]

14 hours ago, houseofjob said:

Awesome, thanks man!

Out of curiosity, do you know as well how to build chargers? Are you an EE?

No problem!

Not an ee but I’ve designed and developed industrial controllers. Building a charger has crossed my mind but there are so many options out there.

I’m in early stages of developing a better charge meter/monitor. Whether that will be completed, time will tell. 

[houseofjob]

20 minutes ago, Rotciv said:

I’m in early stages of developing a better charge meter/monitor. Whether that will be completed, time will tell. 

Nice! would be good to see a 3-digit @hobby16/hobbyist-style charge doctor capable of reading above 100V 

 

[Evgeniy Filippov]

On 8/19/2019 at 11:51 AM, smallexis said:

an external plug directly linked to the power circuit

Cool. )) Can you give more details on how this is done?