Recent content by Lanchon

note that in one of the circuits the signal is driven into the IGND pin instead of VMS RX. this is perfectly fine. but maybe this caused confusion.

did this on the laptop in the waiting room at the doctor's office and took a webcam shot. no desktop, sorry for the unsteady handwriting. (bug: the labels below (VMS to USB and viceversa) are reversed!) I hope it's clear enough. I still don't know the correct polarity for the signals, so I did...

> i'll bet that pump will show less than 4uA leakage from one side to the other the pump doesn't isolate. it's true that it'll tolerate a *DC* bias on it's output, but if you apply an AC bias, it'll feed back through C2 and C3 to U6 and destroy it. current surges on the pack will cause AC bias...

a ghetto-cad schematic... ouch, that hurt! I don't know what polarity you need to use, but you don't need a 3rd power supply. here are the circuits, inverted or not, and with or without buffering (depending on the USB bridge output type): if you want to drive both VMS RX and WAKEUP with the...

> the problem is that there are 3 separate grounds (PC, VMS, Vehicle) and only 2 separate power sources (PC, VMS) and in order to isolate all 3 a third power source is needed. I am attempting to do that using a charge pump... no need man! call the VMS ground "OGND" (for outputs and +5V), and...

> these boards come in 12V and 48V flavors. i believe that this is the 48V you're right.

very sorry to hear about the mishap with your pack. I had a similar episode involving a single A123 cell left on an untested charger that I'd just hacked (badly!) out of a mobile charger. the cell overvolted to 5.5V for a few hours. surprisingly it came out undamaged and to this date it performs...

finally I set the charger to N*3.5V and it failed too... in the end it seems only N*3.65V does the job right.

apparently, the graph that showed increased shunt current above 3.6V was a fluke, I couldn't reproduce it. maybe the VMS boards just delayed the turn on of the shunts and chance had it that the cells were precisely at 3.6V at turn on. I set the charger to N*3.6V and tested... the FET cut on...

> (but I found out that at least I can balance the cells at 3.6V; later...) this is the pack on tricle charge: from sample 0 to 15 the cells are being brought down by the VMSes and the charge FET is off; this is the result of an earlier OVP force and release pair of commands (not shown). at...

> it is most obvious that I sould ditch the so-called "display board" and instead either get an original or roll-my own version of the charge/discharge board. why? if you want to use the FET charge protection, keep in mind that you also need a charger that goes to trickle < 200mA for this...

ok, this BMS was apparently designed with the covert intent of frustrating me. I thought I could solve problem A (4.1V overvolts) for a charger without trickle current by modulating the OVP signal so that cells don't trip over a certain safe voltage. but nooo... when the VMS detects a 4.1V...

> soon as i get the oppourtunity i'll likely discharge my pack till i get the LVP line active and i'll measure the voltage across the LVP opto to confirm. you don't need to if you have serial access. here is the latest version of my scripts. configure in ane-config and use the...

excellent diagram, very clear! I'm happy someone could trace a VMS since all my info was indirect or inferred. so, according to your diagram, if you haven't left out any resistors one can say about CN2 (which is our interesting port): -the 4 output signals include an on-board current limiter...

hi Andy, same here, please do send everything you think might help, and thank you very much again!