TranzX Battery 13Ah 468Wh 36V - BMS Infos needed

[welly]

Hi,

I'm a proud owner of a winora bike with a bl03 tranzx battery. But I'm also a electrical engineer and wanted to read out the bms.

For this i connected my arduino to the battery and used i2cscanner to get the slave address of it (0x0B).
After this successfull scan. I purchased the bus pirate from sparkfun (https://www.sparkfun.com/products/9544).

After using the bus pirate macro, i got the write address 0x16(0x0B W). But no read address. It seems to be that 0x17 is R. Reading out different registers (with [0x16 0x20 [0x17 r:6] f.e.) got me different values, but nothing to get proper battery related values.

So I'm thinking that the battery values are calculated out of different register values. But don't know.

So without destroying my battery I dont know the bms ic. Does anybody know it? Suggestions?

Or is the better way to go to look for proper sniffer hardware for the i2c bus?

I'm open for every advice i can get.

THX welly

 

[grindz145]

Hmm I'm not familiar with the battery. Is it SMBus complaint?! It would be the first I've ever seen. Unfortunately most of that stuff is proprietary to the chip itself. Any idea Whose IC it's based on?

 

[grindz145]

It looks really well designed but I don't see anything on their website which would indicate what the heck is on that bus

 

[welly]

thanks for reply

the battery is like a black box. all i know is from the "analyzer" which has voltage levels of 3.3V for SDA and SCC. This analyzer (no software at hand :-( ) seems to be some kind of usb-i2c-converter with 4 wires (V+ (15V), GND , SDA and SCC) all pluged to the battery. So it could also be a SMBus

May be i found someone with an old - not more used - battery, which i can open.

 

[grindz145]

http://smbus.org/specs/ There is a listing of Registers and stuff there. You can see if it follows this standard at all.

 

[welly]

Well, not really coming forward. But:

"SMBus assigns id 11 (0x0B) to batteries on the bus"

seems to be right in my case

 

[welly]

Yeah! More and more is done.

By using the "bq20z80-V110 + bq29312A Chipset - Technical Reference Manual" I got some proper battery values. But not all are right. So without opening i get some informations. I'll sum it up in the next few days.

Still searching for a list (may be selfmade (may be done my self)) of bms ICs.

 

[grindz145]

I should mention that not all SMBus batteries are 100% complaint to the spec. So if you notice some values don't quite looks right, it may be that, the particular param you're trying to read hasn't been implemented.

Also, bus pirate... hilarious name... just hit me.

 

[welly]

I should mention that not all SMBus batteries are 100% complaint to the spec.

If I understand you right, you mean f.e. the FullChargeCapacity at 0x10 is on every SMBus IC on 0x10. Can't believe this.... We'll see....Still not convinced

Also, bus pirate... hilarious name... just hit me.

Yeah, still thinking of Captain Jack surfing on 1s and 0s XD

 

[grindz145]

I should mention that not all SMBus batteries are 100% complaint to the spec.

If I understand you right, you mean f.e. the FullChargeCapacity at 0x10 is on every SMBus IC on 0x10. Can't believe this.... We'll see....Still not convinced

Haha yup. I designed them for a while. But like I said originally, this would probably be the first SMBus ebike battery I've ever seen.


Do you have any plans to do anything with the data?

 

[welly]

O_O OMG

What a post i have to deal with at the end of my workday. Keep you definitely informed about it.

Try to post overview of readable values the next days.

 

[welly]

I'm back and it seems that i have discovered more and more batteryvalues. But also missleading values.

Is there a common base for the data format on the registers.

Discovered that temperature on 0x08 is still saved in 2 bytes but saved in 0.01K values instead of 0.1K values. Also cyclecount on 0x17 is saved primaly on 8 bytes (dont know what it will do, when it exceeds the range)

List will follow. But is there a total list of "function+register"? The above mentioned PDF doesn't contain something for 0x1d to 0x1f.

Stay tuned
welly

 

[welly]

So finally I'm able to read every register. Bus Pirate failed for reading more than 3 Bytes (unkown cause). So I switched back to Arduino.

Temperature    Voltage   Current            AvgCurrent        RSOC    ASOC
Remain. Cap.   FCC       ChargingVoltage    DesignCapacity    Designvoltage
ManuDate       SerialNumber  ....

and all the others

Thanks for the big hint about SMBus
welly

 

[grindz145]

Nice! Thanks for following up! That is a very nice ebike battery. The fact that they have an actual SMBus complaint ebike battery really speaks to how much engineering effort went into the thing.

How are you planning to interface to the device?

 

[welly]

How are you planning to interface to the device?

Well, "interfacing" is probably not the right word. I would say "getting the data".

My Arduino will do the job. Adding a 16x2 LCD with visualize the data in a loop or by buttons.

welly

 

[grindz145]

How are you planning to interface to the device?

Well, "interfacing" is probably not the right word. I would say "getting the data".

My Arduino will do the job. Adding a 16x2 LCD with visualize the data in a loop or by buttons.

welly

Nice! Are you using it on an ebike?

 

[welly]

Yeah. Thats the fact.

 

[grindz145]

Sweet. I ask because a lot of guys are here for the tech discussions and not ebikes. Nothing wrong with that.

Had a blast riding in to work this morning. Was passing motorcycles and tons of cars. An Ebike is incredible in traffic

 

[welly]

Well, there is one question I couldn't answer at all.

Is there somewhere mentioned in the SMBus Protocol/datasheets to read cellvoltage from (up to) 10 cells in a row? I couldn't find something useful.

welly

 

[grindz145]

Well, there is one question I couldn't answer at all.

Is there somewhere mentioned in the SMBus Protocol/datasheets to read cellvoltage from (up to) 10 cells in a row? I couldn't find something useful.

welly

Do you mean, by using only a single read?

 

[welly]

No , that's not what I was to say.

Somewhere in the EEPROM has to be the cell voltage values. I know that the battery can passiv balance the single cells.

So there was nothing mentioned in the specs i have read. Seems to be different from battery manufacturer to battermanufacturer