Battery Vehicle Society

I am still having trouble getting these new slave boards working. i haven't been working on them a lot, but a bit here and there. the problem seems to be somewhere in the slave boards, cause i can get accurate results using a tested-good slave board. the problem is that the first cell reports accura...

There should be a slave pullup as well, right? Do you have a schematic of the current slave? The only one I know of Is an older version.

edit*

i dont' think i have the v2.00 master schematic either.

i can only attach three at a time, so here are the other views. 4, 5, and 6 are all identical so i didn't attach them all.

i took the following plots off the masterbus with three (i think, i forget now, i'll double check tomorrow, it may have been 4) cells attached. cell1 reads the correct voltage but cell2 and cell3 are reading false (low) voltages. they should all three read 4.02V but cell2 and cell3 are more like 3.2...

changing the baud rate gave me different voltage readings, but still not correct voltage readings. changing the debug baudrate made the display garbled so i changed it back to 9600. i have a couple questions about a few code lines, for example this line in the master where it reads in voltages from ...

getting a few more issues fixed up with these last systems i'm setting up. the old slave boards i used in the past work great, but switching to new boards is giving incorrect voltage readings. i think it has something to do with the new opto's i put on the boards. probably should have tested them be...

thanks greg. i'll try loading it as soon as i get a chance and try to post some pictures. been in the process of moving out of the lab we have been using so it's a slow process. great video btw, i'm using an isolated supply to power the master and an isolated six cell pack for the cells, so it shoul...

i stuck a scope on the slave bus coming out of the master and i'm reading a pulse at 1s intervals, but instead of just a pulse it kicks up and then decays to zero like a capacitor discharging, takes maybe 50ms to decay. (this is with the master board disconnected from the slave board) so maybe it's ...

this looks really nice Greg, glad to see you are making so much progress. how is balancing done? it looks like you are just using the LTC chip directly to dissipate the balance current?

-Isaac

can you think of any reason that the first cell would report the proper voltage and then every cell after the first one reports a lower voltage than the real value. for example the real cell voltages are pretty close to 3.30 and the first cell reports 3.30 and then all the rest report 2.47 and 2.49....