MSXIV BMS Carrier 1.0
- Added a circuit to precharge the relay capacitors
- Added a Raspberry Pi connector for state of charge
- Added a 5 V converter to power the Raspberry Pi
- Added a 3.3 V zener diode to the HSD current sense output to protect MCU during fault
- Changed many 4.7 kΩ resistors to an array
- Changed the LTC6820 package to MSOP
- Added more fan connectors and changed the pinout to support tachometer and 3.3 V PWM
Questions/Comments
Some of these may have already been addressed in REV 2.0, but I'm not sure.
Resistance of the relay coil? - we should make sure that the kill switch circuit has significantly less resistance so that we still supply the coil with enough voltage.
The GND vias beside the feedback traces on the 5V converter are an attempt at eliminating noise pickup, correct?
Are they necessary?
Would routing be improved if they were removed?
Move the SPI headers out from underneath the controller board on future revs?
Has a contactor been chosen for the charger?
Would it be easier to use the EV200HAANA's?
Design time vs cost decision?
We might be able to use some from MSXII or from the bay.
There are 2 LED4s on the schematics of REV 1.1?
LED 5 on the silkscreen is under the outer edge of the controller board. Should it be moved to be more visible?
Chen mentioned the Ultrafit power input terminal was reversed?
Test points should be moved away from traces (12V)
How close are the vias to the isoSPI transformer capacitors (C14, C17)?
6.3V ceramic capacitors for a 5V output? That seems too close. Usually go for 1.53x voltage rating to avoid severe capacitance derating for ceramics.
If switching to microfit connectors, how will we polarize the power input connectors and the kill switch connector?