78PL114S12 - "FCC" value setup on start?

Bob, 

It does look like something is not setup correctly. Can you dump the pack parameters and send them to me? Using bqWizard, go to File >> Save Pack Parameters >> All parameters.

Thanks

Tom

Hi Tom

Thanks very much for replying to my enquiry.

I attach a couple of data files: one for default 3S1P and another for a pack configuration 4S2P.

I had several queries in my post but my priority is to be able to set up FCC on powerup/initialization and understand how FCC is setup.  Ie what sets it to 2400mA in 3S1P?

In the 4S2P file please note that FCC = 0 and Qmax = 0 for cell 4, which I referred to in my post (also most voltage settings such as POV are set for 3S and not 4S) but data also shows 4 cells in series and 2 parallel have been recorded. What has changed FCC from 2400 to 0?  I appreciate FCC is updated at various occasions but it is the initial setup that has me confused.

Most grateful for help!

regards, Bob

Just tried to attach 2 files and it seems to be I am allowed to attach only one (3S1P), I shall replay again with 4S2P file if I can!

 

 

 

 

Tom

4S2P file attached I hope

Bob

 

Bob,

You will need to set the Design Capacity to the combined capacity for the number of cells in parallel. The device should pull this value into the FCC starting point and try to estimate an FCC based on the information in the cell data. You will probably have to go through a learning cycle to update the Qmax estimate in the cell data. Have you done this yet? The device can then make an accurate FCC estimate and Remaining Capacity estimate.

Regards
Tom

Hi Tom

Entering a combined figure in Design Capacity has no effect on FCC (still zero for 4S2P pack configuration). What would you define as a "learned cycle"?  I have charge/discharged cycled 18650's with no apparent success which from what I understand from the tech manual should allow a "learn update". Perhaps I am not reaching a particular setpoint?  What I have noticed is that when discharged and DC goes red The SMBus data "Fully discharged" flag has not been set. Might this signify something?

Regards

Bob

 

Bob, You mentioned earlier that there are four cells in parallel and later that there are two cells in parallel. Is the tmap setup for the proper cell configuration? You also mentioned that you tried several ChemID files and are using 18650E cells. Is the ChemID setup for the cells that you at using? We have an applications report - Chemistry Selection for bq78PL114 that describes the profile required to create an aux file. The aux file generation is a critical part of the learning process. The aux file provides the device with a Qmax estimate and Ra-table for the pack and it can be used to program additional packs. The device will then use this information as a starting point for additional Qmax and Ra-table updates during operational learning cycles. These are when you charge the pack, rest for a couple of hours, discharge and rest again for a couple of hours. Qmax will update during the rest period. If you choose to skip the aux file generation process, then the device will try to update Qmax and the Ra-table during the charge / discharge cycles, but the initial estimate may not be close enough to provide a good update. Make sure the you get CC and DC flags following the charge and discharge cycles, respectively. Usually, we find that the user does not get a flag or does not rest long enough when Qmax updates do not occur. I hope that this helps. Tom

Tom

Apologies if some confusion on my part but can confirm 4 in series, 2 in parallel.   Pretty sure Tmap configuration is correct and I am using the correct Chem file but will re-check. I have copy of the Chemistry Selection application notes and by the sound of your comments clearly the aux file is more important than I realised and I shall do one this week. Definitely did not do  "rest periods" in my charge/discharge cycling. Will keep you posted. Thanks for continued assistance. 

regards Bob