Battery current during engine start
I was a bit curious how much current is pulled during my 5-cylinder diesel start. It's more than I thought. Just before the 8 sec mark the ignition is turned on. The glow plugs pull over 100...
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I see no signs of an inductive kickback. Here's a plot of the battery voltage during the cranking sequence. Data logging connections are at the battery. I would need some gummy arms to snake through the engine compartment to get to the starter. I'm fairly confident any inductive flyback would be evident at the battery.
Around 1.4 sec there's a little dip in voltage. That could be the solenoid getting energized. Shortly thereafter, the starter motor pulls battery voltage down to 9.4V. A little after 2.2 sec the solenoid releases. This is where the inductive voltage spike would occur. There isn't any evidence of one.
Voltage is measured every 1.5 ms.
Yeah, the Arduino data logger is amazing. All for about $20. The clamp-on current probe is a bit more pricey at $75. There's a few brave souls here that are getting into Arduino.
Around 1.4 sec there's a little dip in voltage. That could be the solenoid getting energized. Shortly thereafter, the starter motor pulls battery voltage down to 9.4V. A little after 2.2 sec the solenoid releases. This is where the inductive voltage spike would occur. There isn't any evidence of one.
Voltage is measured every 1.5 ms.
Yeah, the Arduino data logger is amazing. All for about $20. The clamp-on current probe is a bit more pricey at $75. There's a few brave souls here that are getting into Arduino.
