Battery Questions
- How do you select cells?
- how do you design a protective shell?
- mounting options ingrained in the case?
- heat sensing?
- heat dissipation? how important to design for this?
- How to effectively calculate power requirements of a complex system?
- At which stage in the design cycle is the battery designed? (before/after motor selection, before/after full electrical system diagram)
- How to deal with/account for in-rush current?
- testing vs calculation
- battery placement within the system? - is this important?
- sourcing? CELL VENDORS THEMSELVES
- Active vs Passive balancing?
- Copper wiring/Soldering
- Connectors
- Assembling the battery - how important to test each cell and specify each cells location based on resistance?
- Spot welding - worth it to make a pcb supercap thing for that?
- bms on the battery? or separated?
- hexagonal or square grid pattern?
- vertical stacking? - some one else advised against this, but it might be nice to have a flatter battery NO DONT DO THIS
- how to charge, with bms or without?
- What to expect during assembly?
- expected costs? cost savings?
- Other cell chemistries to consider?
- Diagnostic tests to run?
- Critical data query functions?
- Hierarchy of protections?
- Firmware Architecture? Use OOP to send commands to BMS and store data?
- Is it useful to manually trigger the FETs or allow BMS to handle it?
- Ideal calibration procedures?
- Optimal to use IC as a peripheral and have microcontroller sample it for necessary data?
- When to use FUSE functionality?
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Notes at meeting:
- big motors need to be at Vbat,
- Data, Calculations: peak power, total power
- higher discharge, lower life
- 50E, 30H - power drill batters - life around 50A
model system as good as posible to see the loads
power train loads will dominiate
- biggest incline, target speed, - gearboxes → efficiency
- can translate speed up a hill to power requirement
- get current requirements
get battery current requirements
NEED TO CONSIDER POWER REQUIREMENT AT LOWER STATE OF CHARGE
power draw relartive to battery size → look into heat dissapation
size away the problem by making battery bigger → make issue go away eg lower C rating
Ampacity or Energy
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IC Specific(may not be useful)
Avoid shutdown in favour of deepsleep? Save data to OTP before shutdown?
Uses for SEALED security?
Use permanent fail to brick chip? Avoid using PF if not intending to blow fuse?
How to get the Chip to be recognized by BQstudio?
Chip's internal die temperature reliable? OR is using an external thermistor better?