Batterie: auf der Suche nach der Energie | Posts 16+

Hi!

Okay, so let me briefly explain again why I'm bringing up this topic.

I stumbled upon this topic by chance and read it because I was interested. After reading about the problems that the user (UP) described, I wanted to watch the videos.
But with my village internet connection and my old computer, I had no chance of doing that.
So, I looked at the data log, and it was clear to me (assuming the measurements are correct) that a power diode in the alternator is faulty.
Because all of this aligns perfectly with the readings, the constantly dead batteries, and my own experience.

Well, and since no one suspected anything like that (which seemed strange to me).
I thought I'd add something to this, just so that in six months we don't get another post saying: "Help, my new battery is also constantly draining again."

Is everything clear?

Hi,

"In my opinion, the power supply seems to be working quite well according to the logs. I can't imagine a power diode burning out (although I had to deal with that issue recently, but that's a different story...)."

It regulates the voltage cleanly to approximately 13.8V, even after turning on the heating elements to levels 1 and 2. The heating elements represent a significant electrical load. If one of the power diodes were defective, it is highly likely that the 13.8V level could not be maintained.

Despite what was said, 13.8V isn't exactly impressive, but we don't know the measurement error of the OBD data. However, in the original post, the user shows a reading of 14.14V on a digital multimeter. I think this indicates that the alternator is working correctly.


Best regards, Georg.

Hello!

Yes, I couldn't see the 14.14V with my old computer; I could only view the log.

Otherwise, I'll try to describe it in my own words:
Sure, I will translate the text from German to English and correct any errors. Please provide the text you would like me to translate.
An alternator for three-phase AC power delivers approximately 50% of its electrical output at idle speed.

Assuming a 90A alternator, that would be 45A, simply calculated based on 12 volts.
That would be approximately 500 watts.
And in doing so, a healthy battery must also maintain its nominal voltage, typically between 14.15 and 14.4 volts.
The nominal voltage in this range is likely dependent on the controller temperature, or, in newer Lima models, it is set according to the controller temperature.

For now, I'm going to set aside battery management systems, as my knowledge of them is only very basic.

I usually test the Lima by turning on enough appliances to consume approximately half of its rated power output, and the battery must be fully charged beforehand.
The engine needs to run at approximately 2000 RPM.
Then I'll measure the voltage at the battery and again directly at the alternator.
And what's below 14V is not acceptable.

There's no charging indicator light, and you don't notice anything unusual otherwise; you just wonder why the battery is always weak.

If I'm not currently installing a replacement fuel pump or some other cheap internet gadget...
I'll take it to a retired mechanic in the neighboring town who repairs Linuses.
He has a testing bench where we can check the values before and after any changes. He also tells me what he replaced or what was broken.

Typically, in this case, at a voltage of 13.6-13.8V, it is a power diode.
It's happened quite a few times, almost always the same thing.

Typically, these are the 120A Linas, which tend to experience such problems around 150,000 kilometers.
"The bearings are a bit weak and running roughly. This can cause the carbon brushes to stop working properly or become dirty/jammed. The slip rings may also be worn out or burnt."
It then connects the coal and the anchor.
This will cause voltage spikes that eventually damage the weakest diode.

He explained it to me like that and also showed me numerous examples of old parts.
Or I just waited until he had taken the alternator apart, and then we checked it together.

Ultimately, the generator will only operate at two-thirds of its capacity. You don't really notice it because, in summer and without lights or other loads, it easily handles its rated voltage.
It can also be used in the summer with lighting, etc.

But especially in the winter, when everything that needs electricity is running at once, plus cold starts.
Then the power output of the Lima is no longer sufficient, which causes the voltage to collapse.

Approximately 13.7V is a very typical reading in that case.