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Salvo's avatar
Salvo
Explorer
Feb 25, 2016

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 100A.

After 12 sec the engine is cranked. Current spikes to over 700A. It takes about 1 sec to start. After ignition, glow plug current settles to about 90A.

At 16.5 sec the alternator kicks in. Battery current ramps (negative) to about 20A. The battery is now charging. Negative current is charging current.

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  • Salvo's avatar
    Salvo
    Explorer
    Feb 26, 2016
    I'm using a current clamp (Hantek CC-650). The Hantek has an analog output which is connected to a 16-bit A/D. The A/D connects to an Arduino datalogger. Data is recorded at 1.5 ms rate.

    What is EMF?
  • SCVJeff's avatar
    SCVJeff
    Explorer
    Feb 26, 2016
    Nice! I assume the 100A are the heater/ glo-plugs, and the little rise after start is starter EMF releasing?

    Got a QuietDiesel 7500 anywhere to look at?
    My Dranetz is somewhere on the East coast and I don't think it does DC either

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