BQ20Z80A-V110: EV2300 Windows XP bq20z80

Thanks Onyx!
Now I have another issue maybe I can reach out to you directly via email. We are reworking some older packs with new cells around this older bq20z80/bq2931a and Bq29401 OV solution. When we connect the cells, a fuse blows and/or the FET that is controlled by the 29401 blows. Can I send you the schematic for this board for your review, obviously we are missing something and it is our customer's design. Also, on discharge, the AOCD fault occurs prematurely. I am confident in the settings, so that may also have to do with the board itself.

Thanks!

Joe Perino
VP & GM
Nova Battery Systems

On some designs you must be sure to carefully connect the cell tabs in the right order, from lowest potential to highest potential, in order to prevent false detection of abnormally high cell voltages. Sometimes customers have designs with solder jumpers which are added or removed after cell attach is complete to prevent false detection during attach. See if the board you are working with has such a feature which you can leverage, or else try to carefully attach the cells in the right order.

Hello. Thanks for the prompt response. There is no doubt NBS is connecting the cells in the proper order. As a matter of fact, we tried it both ways just to be sure and blew a 2.5A fast-blow fuse on the board every time. With the cells connected and the fuse bypassed, the Q1 FET in the schematic, which is controlled by the bq29401 output to blow a second fuse, burns up. I cannot find issue with the schematic or design, but again it is not our design. We made some boards using customer-supplied gerber files. It might be helpful if someone at TI could take a quick look, maybe it is something obvious to you that we are missing. Thanks.