- Checked balancing. And started balancing the next "bank"
- Created board to connect all balance taps together, and soldered on cable to remotely connect: (a) 'fuel' guage, (b) BMS, (c) charging "shunt" connectors.
- Tested my circuit idea for switches to be 12v potential only, not 42V (Note to self ... didn't thoroughly test or understand this last time around).
- Tested circuit idea for 75 ohm resistor on the "stop" switch. Doesn't work !
- Tested 4 x 110 ohm resistors (instead of 2 x 220 ohm). Still far too hot !
- Tested 4 x 150 ohm resistors. Burning hot to touch. No good !
- Good news ... is that the Zener is cool.
- Tested 3 x 150 ohm + 1 x 220 ohm. Not enough power for circuit.
- Rough calculations: LM555 = 15mA. Relay = 12V, 282 ohms = 42mA. Capacitor etc (say) 5mA. Total 62mA. Measured = 64mA
- Drop over the 4 resistors is 30volts, at 64mA = 1.92W ... or 0.48W / resistor
- Better relay is 331 ohms, 36mA. Save 6mA. Power = 1.74W being 0.43W / resistor
- Decision = buy 4 x 150 ohm resistors,
Things I want to do today
- Cut the 'balancing' board and the circuit board.
- Cover balancing board in insulation. Bind safely.
- Etch the circuit board.
- Drill the circuit board.
- Mount parts ?
