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+--- Thread: Voltage drop when start the car (/thread-872.html)
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Voltage drop when start the car - mentalinc - 06-27-2019
Any ideas on how I can stop voltage drop when I start the car from rebooting the PI?
i.e. When I turn the key to start the engine the screen fades out and the Pi reboots. I have a capacitor connected (10µF 16V), but wondering if it's too small to handle the second or so while the engine starts?
RE: 2014 mazda 6 - GFunkbus76 - 06-29-2019
Do you have it connected to constant power? Some drop power when ignition is hit.
RE: 2014 mazda 6 - mentalinc - 06-29-2019
It's "constant" in that when the ignition is off there is still power, but it seems there is a drop when ignition is turned on.
Any ideas on how to cover the voltage drop?
RE: 2014 mazda 6 - GFunkbus76 - 06-30-2019
Then I do not think it's constant. In my VW it's call the X circuit. Wipers, headlights and other "high draw" items are cut when applying ignition to starter - I think you maybe taped into one of these lines? Maybe I'm incorrect.
RE: Voltage drop when start the car - ashwaganda - 10-21-2019
(06-27-2019, 06:58 PM)mentalinc Wrote: Any ideas on how I can stop voltage drop when I start the car from rebooting the PI?I had the same issue and it turned out my car battery was getting seriously old. New battery solved the problem for me.
i.e. When I turn the key to start the engine the screen fades out and the Pi reboots. I have a capacitor connected (10µF 16V), but wondering if it's too small to handle the second or so while the engine starts?
RE: Voltage drop when start the car - Frank - 10-22-2019
I read elsewhere about using a capacitor to even out the current. I know only enough about it to be dangerous. However, I did find a capacitive kind of line filter that might do the trick. https://www.amazon.com/Voltage-Stabilizer-Protector-Regulator-DC10-36V/dp/B06Y5JHZG2/ref=sr_1_1?keywords=12+volt+current+stabilizer&qid=1571759367&sr=8-1
RE: Voltage drop when start the car - Matthias - 03-19-2021
I have exactly the same Issue. I don't understand that not more people experience this problem. I can do a save shutdown, but every time a start my car, the voltage drops and my pi reboots. So without a stable 12V source, everything you do is kind of useless (I have a brand new car battery by the way). I will try the voltage stabilizer and I hope this will solve the problem.
RE: Voltage drop when start the car - KreAch3R - 03-19-2021
You should get power straight from the battery and "regulate it" with an ignition-ACC source. Are you guys doing that and also experiencing drops? Another workaround would be to power the pi after you start the engine.
RE: Voltage drop when start the car - Matthias - 03-20-2021
I'm getting power "straight" from the battery using a fuse tap(https://www.amazon.de/gp/product/B07DMVQPWJ/ref=ppx_yo_dt_b_asin_image_o04_s00?ie=UTF8&psc=1). I measured the voltage and it is definitely not cut-of. The power drops to 10.5V when the engine starts, which results in powering off the raspberry pi.
You also see this drop in voltage when you start the engine with head lights on: the intensity decreases for a second while starting.
My car is 15 years old (diesel), so I can imagine that starting such a car requires more from the battery than starting a brand new hybrid toyota prius for instance.
Let's hope the voltage stabilizer will fix the issue.
RE: Voltage drop when start the car - budman1758 - 03-20-2021
@matthias
What power supply are you using?