Test: energy absorption

[Vins213]

Hi!

I wanted to do a Christmas test about the absorption of my Yaris Hybrid 2017.

I have an aftermarket head unit, with the HU disconnected and after 10mins from locking the car, I have 1.3mA

Then I unlocked the car, started the HU and setted the sleeping mode ON, shut the car down and locked, waited 15mins and....1.4mA

 

not bad or not?

[Roy124]

Vincenso, I am not sure that proves anything yet.  First off, the two time intervals are different.   Then a 0.1 difference is too close to be significant. 

Consider a reading at an accuracy of 0.01 but rounded to 0.1.  The first could really be 1.34 and the second 1.36.

What is the stated accuracy of your meter?

[Mjolinor]

I can't work out what you are measuring. Are you trying to measure the power consumption of the vehicle?

 

[Vins213]

6 minutes ago, Roy124 said:

What is the stated accuracy of your meter?

IDK Roy 🫥

1 minute ago, Mjolinor said:

Are you trying to measure the power consumption of the vehicle?

Yes, in locked position...I wanna know the power consumption of the Junsun HU in sleep mode (it has a boot up about 40sec with sleep mode OFF, and about 3sec with sleep mode ON)

[Mjolinor]

So you have the meter connected in series with the HV Battery? EEK, that is a good way of letting the smoke out of your meter.

 

[Vins213]

1 minute ago, Mjolinor said:

So you have the meter connected in series with the HV battery? EEK, that is a good way of letting the smoke out of your meter.

 

nope, in series with the small 12v Battery 🙂 

[Mjolinor]

I do not think you will get anything meaningful doing that.

The hybrid Battery is still connected to the car presumably so why do you think power will be taken from the 12v Battery in that situation? It may well be taking power form the HV Battery to power any ancillaries.

The way to check the HU is on the bench or from the manufacturer specification if you think you can believe what they are saying or put the meter in the earth lead of the HU itself.

The way you are trying to do it will not give meaningful results IMO.

 

[Vins213]

4 minutes ago, Mjolinor said:

I do not think you will get anything meaningful doing that.

The hybrid battery is still connected to the car presumably so why do you think power will be taken from the 12v battery in that situation? It may well be taking power form the HV battery to power any ancillaries.

The way to check the HU is on the bench or from the manufacturer specification if you think you can believe what they are saying or put the meter in the earth lead of the HU itself.

The way you are trying to do it will not give meaningful results IMO.

 

the HV Battery is connected to the car when the car is on READY...with the car locked or unlocked and in ON or in ACC mode, the power is taken from the 12v Battery, not the HV 

[Mjolinor]

If that is the case then your measurement is extremely low. There is no way that only 1.4 ma is flowing in that situation.

It is really unwise to use the current setting on a meter in this way. It only needs a small load and your meter will stop working. The current settings have very little protection.

I am still unsure how you are doing this. Is the meter connected when you lock the car? If so I am surprised it has not blown already and if you are locking the car then connecting the meter the car is not in the normal state because you have disconnected the Battery in order to connect the meter.

[Vins213]

2 minutes ago, Mjolinor said:

because you have disconnected the battery in order to connect the meter.

I think you don't know how the things are done

 

for me, 1.3mA are a bit too much for the closed car (about 5 days of no car start and the 12v will say bye bye), but lets wait the PRO users like Bob 😁

[Vins213]

41 minutes ago, Roy124 said:

Vincenso, I am not sure that proves anything yet.  First off, the two time intervals are different.   Then a 0.1 difference is too close to be significant. 

Consider a reading at an accuracy of 0.01 but rounded to 0.1.  The first could really be 1.34 and the second 1.36.

What is the stated accuracy of your meter?

This is with the 20A scale, 10mins from the two readings

 

0.15A without the HU
0.16A with the HU in sleep mode ON

 

[MikeSh]

12 minutes ago, Vins213 said:

0.15A without the HU
0.16A with the HU in sleep mode ON

Those numbers are more in line with expectations and two orders of magnitude higher than your original post. (150mA instead of 1.3mA.)

[Mjolinor]

13 minutes ago, Vins213 said:

I think you don't know how the things are done

 

for me, 1.3mA are a bit too much for the closed car (about 5 days of no car start and the 12v will say bye bye), but lets wait the PRO users like Bob 😁

 

For sure I have no idea what you are doing but 1.4 ma works out to about 0.017 watts, that is to say that it will take over two days to consume one watt hour. At that rate you could run it for months before there was any noticeable volt drop on the Battery.

If the Battery is (for example) 50 Ah then it will take four months to flatten it

What is the Battery capacity?

[Vins213]

Just now, Mjolinor said:

What is the battery capacity?

35Ah, less than 5 days with 0.16A without starting the car

[Mjolinor]

 

Ah. Why has the data changed?

I think you need to start again and explain a bit more about what you are trying to do and how you are trying to do it.

 

 

[Vins213]

1 minute ago, Mjolinor said:

 

Ah. Why has the data changed?

I think you need to start again and explain a bit more about what you are trying to do and how you are trying to do it.

 

 

I have changed the scale, as you can see in the photos

I repeat: I'm trying to see the power consumption of the Junsun HU in sleep mode ON, do you know that HU and that mode? 

[Mjolinor]

160 ma is too much

4 minutes ago, Vins213 said:

I have changed the scale, as you can see in the photos

I repeat: I'm trying to see the power consumption of the Junsun HU in sleep mode ON, do you know that HU and that mode? 

No but I do know electricity and cars, batteries and how to measure / interpret data.

You need to measure this on the HU, not at the 12 volt Battery. Put the meter in the HU ground (-ve) lead.

I think the meter is misleading you here. There is no reason for the power to increase my a factor of a hundred simply by changing the scale on the meter. It should read the same amount irrespective of the scale provided you are not over the maximum. All that should change is the number of decimal points or resolution.

[Vins213]

5 minutes ago, Mjolinor said:

160 ma is too much

No but I do know electricity and cars, batteries and how to measure / interpret data.

You need to measure this on the HU, not at the 12 volt battery. Put the meter in the HU ground (-ve) lead.

I have disconnected the negative from the 12v, bridged with the (+) meter to the negative cable disconnected and the (-) meter to the negative on the 12v

 

if I open a door, the measure is the power absorbing of the lights and display info...or no?

[Mjolinor]

1 minute ago, Vins213 said:

I have disconnected the negative from the 12v, bridged with the (+) meter to the negative cable disconnected and the (-) meter to the negative on the 12v

 

if I open a door, the measure is the power absorbing of the lights and display info...or no?

Mostly yes, you have to add any other things that may be consuming power.

That may be a lot of other things such as your alarm, lock controller, radio receiver and possibly a whole host of other things. You need to measure this at the HU or you will not get any meaningful results.

You could measure it this way and while measuring then disconnect the HU and note the difference. I don't think it will be a very accurate way but it may show a difference.

 

[Vins213]

Just now, Mjolinor said:

Mostly yes, you have to add any other things that may be consuming power.

That may be a lot of other things such as your alarm, lock controller, radio receiver and possibly a whole host of other things. You need to measure this at the HU or you will not get any meaningful results.

You could measure it this way and while measuring then disconnect the HU and note the difference. I don't think it will be a very accurate way but it may show a difference.

 

Understand, but I'm doing this to see the delta with the HU with the sleep mode and without the HU...and this delta is acceptable 0.15A vs 0.16A

I don't wanna know the power of the HU but the difference with/without the sleep mode 🙂 

[Roy124]

42 minutes ago, Vins213 said:

This is with the 20A scale, 10mins from the two readings

No, you said in one state 10 minutes and in the other 15 minutes. 

I am not talking amps/volts or whatever but data reliability.

Your timescales are very short.  Doing over 24 hours, or even 2 hours, will allow for a more measurable difference. The time the period the less sensitive the measurement.  

Returning to the Battery drain, I have collected data at 24 hour interval over a number of days.  That is less sensitive to measuring inaccuracy.  

Experience has shown that the rate of change reduces over time.  With a short time scale the loss suggests a flat Battery in 2-3 day.  Measuring over a longer period suggests the Battery will not be flat in under 3 to 4 weeks. 

[Vins213]

Just now, Roy124 said:

No, you said in one state 10 minutes and in the other 15 minutes. 

That's for the second reading, look at the scale, I have also wrote it down

[Vins213]

This is from my other Yaris III, 2014 diesel, after 10m from locking the car, 20A scale

Merry Christmas 🎄 

[Dala]

It is better to measure them after turning off the ECU. About 40 minutes for me.

[Vins213]

16 minutes ago, Dala said:

It is better to measure them after turning off the ECU. About 40 minutes for me.

K, I'll try! Thanks