Cell impedance of Thundersky and CHL lithium battery

105 replies [Last post]

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
ElectroLex
Offline
Joined: 06/03/2009
Points: 17
Re: Cell impedance of Thundersky and CHL lithium battery

ElectroLex wrote:

Is this the GBS? If not, who's is it?

Sorry - that was intended to respond to posting #39.

__________________

--
EVTA R-20 with Kelly Controller - 2,500 km (odometer)
XM-3500li with 3,500 km and Fechter/Goodrum BMS

CO2
Offline
Joined: 07/24/2011
Points: 110
Re: Cell impedance of Thundersky and CHL lithium battery

CHL lithium battery wrote:

Ok,now it is only chinese version,we will convert into Enlish version after bulk production.see below
24 cell BMS.jpg

And English version, when?

pcarlson1979
pcarlson1979's picture
Offline
Joined: 02/20/2011
Points: 461
Re: Cell impedance of Thundersky and CHL lithium battery

CHL lithium battery wrote:

Thanks for your explanation,you are very professional.

Of course we can compose 100V even higher voltage,like we supply for Mountain chen's 28cell maxi scooter.

But our BMS by now only for 20cell, 24 cell active BMS will come out next month.

Something went wrong then. Because its now August and I was sent a no name passive BMS with no fuel gauge function. Personally I was pretty dissapointed and I hope CHL will accept dead cells from packs from waiting over a year for a CHL BMS.

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

high voltage an...
high voltage and high discharge BMS system's picture
Offline
Joined: 12/15/2011
Points: 25
Re: Cell impedance of Thundersky and CHL lithium battery

Hi,I mean you use a big capacity cell, it is better to fixed with a high current/balanced BMS system, we'd like to provide the support if needed, please view www.szcoresun.com, or http://www.szcoresun.com/cpzs2-high%20current.htm

pcarlson1979
pcarlson1979's picture
Offline
Joined: 02/20/2011
Points: 461
Re: Cell impedance of Thundersky and CHL lithium battery

Hi Everyone.

Well I have finished my 48v electric dirtbike conversion. I am using 16 of these CHL 50Ah cells because he claims they can do 6C continued discharge.....RUBBISH! The MOST I can get out of the FRESH off the charger is 220A, that's 4.4C but usually I get 170A that's only 3.4C. Even at 3.4C the cell voltages are dropping to 2.63v per cell. VERY close to the 2.5V cutoff. And after using the top 6Ah the battery then struggles to even supply 2.8 to 3C.

So people, I am a REAL life user with REAL results. I did not get the performance I was promised. But in my electric scooter where the current is limited to 115A these batteries work fine. My suggestion is to only pull 2 to 2.5C from these CHL 50Ah cells. I rate these cells as 3C MAXIMUM. They will go more, but they will really struggle.

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

CHL lithium battery
CHL lithium battery's picture
Offline
Joined: 02/23/2011
Points: 305
Re: Cell impedance of Thundersky and CHL lithium battery

16 cell in series connection? are you sure of good connected ? how many V when you full throttle ?

What production day of these battery ?

Pls tell us the series number on top of CHL battery so that we can find out history of these battery.

Thanks for your help !

pcarlson1979
pcarlson1979's picture
Offline
Joined: 02/20/2011
Points: 461
Re: Cell impedance of Thundersky and CHL lithium battery

CHL lithium battery wrote:

16 cell in series connection? are you sure of good connected ? how many V when you full throttle ?

What production day of these battery ?

Pls tell us the series number on top of CHL battery so that we can find out history of these battery.

Thanks for your help !

Hi CHL,

Yes I have 16 cells connected in series (4 block containing 4 cells each). I am using heavy 2 gauge wire inbetween each block of cells. I have attached a photo showing the wires during test phase before the bike was finished. The wires inbetween the cell blocks are 15mm in diameter. Yes I'm sure that all the wiring is strong and tight.

I have the controller low voltage set to 41v so the closer the voltage gets to 41v the more it will limit Amps. I usually get a short peak of 200A but it settles to 170A because the voltage sits around 42v at 170A. But when the Amps get around 200 the bike is a BLAST to ride!! If I set the controller to 44v Low Voltage cutoff I can only pull around 85A and the bike is very slow and boring to ride. The charger cuts off at 58.4v and settles around 56v. But just riding the bike slowly out to the car park 10m away pulling 3 to 4 Amps make the voltage drop to 49v pretty easily. After 3 Ah used the voltage bounces back to 48.8v. The most I've used from the pack so far is 16.1Ah and the bike still felt really quick pulling 170Amps or more.

Don't get me wrong, I'm not saying your cells are bad, I was just saying they seem to be more like 3C cells, not 6C. I was not expecting the voltage to sag all the way down to 42v (2.625v each) though! My 8000w scooter barely hits 70v (2.917v each), but the scooter limits power at 115A. I have seen a Voltage minimum of 41.9v so the controller is doing it's job limiting Amps to make sure the batteries don't hit that 40v mark.

I am not home at the moment so I can't get the numbers off the cells, but I do remember they had writing on the side.

Wires.JPG

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

CO2
Offline
Joined: 07/24/2011
Points: 110
Re: Cell impedance of Thundersky and CHL lithium battery

I think 6C, only the new CALB can....

Johnny J
Johnny J's picture
Offline
Joined: 07/08/2008
Points: 333
Re: Cell impedance of Thundersky and CHL lithium battery

I have now taken my Thunder apart to mount the BMS and Cycle Analyst.

First thing I did was measuring the voltage of the 24 CHL batteries and...they were all between 3.343 and 3.345V!!!
2 thousands of a Volt difference!

I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)

CO2
Offline
Joined: 07/24/2011
Points: 110
Re: Cell impedance of Thundersky and CHL lithium battery

Johnny J wrote:

I have now taken my Thunder apart to mount the BMS and Cycle Analyst.

First thing I did was measuring the voltage of the 24 CHL batteries and...they were all between 3.343 and 3.345V!!!
2 thousands of a Volt difference!

I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)

To have a correct measuring you need make in discharge and not when the bike is off!

Johnny J
Johnny J's picture
Offline
Joined: 07/08/2008
Points: 333
Re: Cell impedance of Thundersky and CHL lithium battery

CO2 wrote:
Johnny J wrote:

I have now taken my Thunder apart to mount the BMS and Cycle Analyst.

First thing I did was measuring the voltage of the 24 CHL batteries and...they were all between 3.343 and 3.345V!!!
2 thousands of a Volt difference!

I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)

To have a correct measuring you need make in discharge and not when the bike is off!

"I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)"

CO2
Offline
Joined: 07/24/2011
Points: 110
Re: Cell impedance of Thundersky and CHL lithium battery

Johnny J wrote:
CO2 wrote:
Johnny J wrote:

I have now taken my Thunder apart to mount the BMS and Cycle Analyst.

First thing I did was measuring the voltage of the 24 CHL batteries and...they were all between 3.343 and 3.345V!!!
2 thousands of a Volt difference!

I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)

To have a correct measuring you need make in discharge and not when the bike is off!

"I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)"

All know: cells go always to nominal voltage.
When I did measuring the voltage, I put the tire in the air, max acceleration (about 20ah, ideal is 50ah in your case), and then I see voltage, cell by cell...that's the correct to do. TRy and report.

Johnny J
Johnny J's picture
Offline
Joined: 07/08/2008
Points: 333
Re: Cell impedance of Thundersky and CHL lithium battery

CO2 wrote:
Johnny J wrote:
CO2 wrote:
Johnny J wrote:

I have now taken my Thunder apart to mount the BMS and Cycle Analyst.

First thing I did was measuring the voltage of the 24 CHL batteries and...they were all between 3.343 and 3.345V!!!
2 thousands of a Volt difference!

I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)

To have a correct measuring you need make in discharge and not when the bike is off!

"I know measuring them resting doesn't give you the right picture, but it´s still quite amazing :-)"

All know: cells go always to nominal voltage.
When I did measuring the voltage, I put the tire in the air, max acceleration (about 20ah, ideal is 50ah in your case), and then I see voltage, cell by cell...that's the correct to do. TRy and report.

---------------------------------------------------------------------------------------------------------------------------------------------------------

Right now I have no way of measuring them individually simultaneously, on my former scooter I had Cell-logs with logging which I could use for this.
Thing is I also have an electric car with Thunder-Skys and at resting they differ around 80mV between highest and lowest, so there is a difference.
It propably mostly has to do with how well the factory matches the cells on delivery, but also the general quality.

CO2
Offline
Joined: 07/24/2011
Points: 110
Re: Cell impedance of Thundersky and CHL lithium battery

Or they are old with fast discharge....

Johnny J
Johnny J's picture
Offline
Joined: 07/08/2008
Points: 333
Re: Cell impedance of Thundersky and CHL lithium battery

CO2 wrote:

Or they are old with fast discharge....

Not very old and with very few cycles...actually I measured this when they brand new aswell.
It might be that they "even up" with more cycles, but I doubt it.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Who's new

  • polak187
  • lskxokpin
  • mick_wilt
  • Alex1971
  • bennelson
Customize This