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chemistry learning

Other Parts Discussed in Thread: BQEVSW

sir,

 

during chemistry learning there are in between steps of relaxing the cells

 

this relaxing means,  disconnecting cells from 1N to 4P,    or just the removing charger and load.

 

becoz if cells are removed, then EVM goes in shut down and learning process breaks,  so i hope cells are to be keep connected to evm and remove just load and charger for relaxing

 

isn`t it?

 

 

but in step  of learning where it says, pulse discharge from 10% to 3v, it completes the step and goes to step 7 of relaxing , so i remove the load to relax, but again it goes back to step 6 and says EXTRA STEP, pulse dischrge from 10% to 3v requres more time, so i connect again load then it deschages and goes to step 7, but this  happens over and over and each time it starts timer from 0, for 5 hrs relaxing, co never completes step 7

 

pls help

 

thanks and regards

rohit

 

  • what is the meaning pf pulse discharge in chemistry learning step 6?,  is it not  normal discharge?

  • cells must be connected all the time.

    when you do a chemistry learning follow the steps of bqeasy,first of all ,you need to build a circuit like below:

     

    i remember after press the 'start test' buttom of bqeasy,it will automatic wait for 2 hours ,discharge the battery to 60%,and relaxation for 2 hours,then discharge to 10%,relaxation for 2 hours,discharge the battery to empty,waiting for 2 hours.

    after these steps .it can get 4 OCV dots of your tested battery.bqeasy will check the database of chemistry ID(every chemisty ID correspond a OCV Curve)and then get the best match ID with this 4 OCV dots.also it will report the error rate,less than 3% can be accepted.

    you should also check your bqEVSW  whether is the newest version.

     

     

  • Hey macy, thanks a lot

     

    i have gone through all these steps few days back. but at last when i clicked on,  MATCH BEST CHEMISTRY, it shown me some error releted to USB and i had no option other than clicking on OK, so i clicked and thet BQEASY screen was just inactiveted, i was unable to clik anywhere on bqeasy tab,   but i could access data flash, sbs, pro, calibaration screen.,  so i closed application. and hence finally chemistry learning was wasteful,  wasting my 3 days of learning.

    See durin discharge step, my arrangment is like below,

     

    cells connected to 1N to 4P, load is conneted to PACK+ and PACK- as u have shown in above fig, but  instead of Vout and GND i have given external 5v supply,  becoz  my  EV2300 is not showing voltage at Vout pin.

     

    SMBUS of  EV2300 is kept connected to EVM smbus, and tried to connect the Vout of  I2C,  but no supply at vout so gave external supply,

    pls help

  • Vout is not always be high. the bqEVSW will control the Vout pin pull high through EV2300 when discharge is needed.in relaxation status,Vout pin always pull low.   how can you make sure that the external 5v supply synchronize with the software between ralaxation and discharge?

    there is another way to get the suitable chemistry ID.charge the battery to full,waiting for two hours. then use a light loading (the current is about C/10 always be OK )  to discharge the pack to empty,and then waiting for 5 hours.use the bqEVSW  to log all the steps. finally  you can use 'mathcad'  to calculate the best matched chemistry ID. pls reference this document:  http://focus.ti.com/lit/sw/sluc138f/sluc138f.zip

     

     

  • Thanks a lottttttttttttttt macyy [:D]

    i will try it out

     

    means at a time both SMBUS and I2C are kept connected during dischrge ,   right?             ,, so that algorithm will also work and discharge also work .