PicoScope 7 Automotive
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Parasitic Load Test
Parasitic Load Test
Afternoon All,
I have carried out a parasitic load test earlier today due to the battery draining over night, you can see the ECU's shutting down over the first few minutes then they shut down and the current draw goes to negative 2 amps.
My question is, is this a load or a something I should dismiss ?
Regards
I have carried out a parasitic load test earlier today due to the battery draining over night, you can see the ECU's shutting down over the first few minutes then they shut down and the current draw goes to negative 2 amps.
My question is, is this a load or a something I should dismiss ?
Regards
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Steve Smith
- Pico Staff Member
- Posts: 1588
- Joined: Sun Aug 25, 2013 7:22 am
Re: Parasitic Load Test
Hello and thank you for the post
Sorry, I cannot see the reverse current based on the screen shots as the scale is missing
Prolonged parasitic drain measurements do come with a number of challenges which you can read about here along with an alternative method here
The main issues are “Zero point” of the current clamp & thermal drift which you can read about above
If you suspect reverse current (i.e. current allegedly flowing into the battery rather than away) during parasitic drain measurements, momentarily remove your current clamp from the cable under test and note the zero/drift.
Often you may find your zero point is not longer at zero and may have drifted to a minus value. In this scenario re zero the clamp and refit to the cable.
The other possibility could be the minus value is correct if this is an Electric Vehicle or a vehicle with twin batteries where you have captured battery equalization
I hope this helps, take care…….Steve
Sorry, I cannot see the reverse current based on the screen shots as the scale is missing
Prolonged parasitic drain measurements do come with a number of challenges which you can read about here along with an alternative method here
The main issues are “Zero point” of the current clamp & thermal drift which you can read about above
If you suspect reverse current (i.e. current allegedly flowing into the battery rather than away) during parasitic drain measurements, momentarily remove your current clamp from the cable under test and note the zero/drift.
Often you may find your zero point is not longer at zero and may have drifted to a minus value. In this scenario re zero the clamp and refit to the cable.
The other possibility could be the minus value is correct if this is an Electric Vehicle or a vehicle with twin batteries where you have captured battery equalization
I hope this helps, take care…….Steve
Re: Parasitic Load Test
Afternoon Steve.
I will give this ago tomorrow just for piece of mind, this is very interesting reading.
We did fix the issue of the discharge, one of the ECU's would randomly wake up. We checked the ignition supply to the controller and this was off at the time of the wake up. We flashed a older version of software in to the controller and this fixed the issue. Looks to be a bug in the software.
Thanks for your help, Regards Simon
I will give this ago tomorrow just for piece of mind, this is very interesting reading.
We did fix the issue of the discharge, one of the ECU's would randomly wake up. We checked the ignition supply to the controller and this was off at the time of the wake up. We flashed a older version of software in to the controller and this fixed the issue. Looks to be a bug in the software.
Thanks for your help, Regards Simon