Erfahrungen mit dem Laderegler "microcharge" | Posts 32+

Diesel wrote:

Just check if you can isolate and bring out the "B+" connection between the generator and the regulator externally.

I had also considered that, because it seems like a logical option.

But then I start having bad thoughts again: "What happens if the thick B+ cable has a loose connection?" -> Then, in my opinion, the alternator voltage would run up unregulated, and the diodes could potentially fail due to exceeding the reverse voltage, voltage spikes, etc.

How does the µcharge system react to such errors?

First, I will determine the voltage drop on the B+ cable as accurately as possible in order to determine the maximum potential for improvement -> "would it even be worth it?"

Bertil wrote:

That was a loooooong time ago... "On his website, he also refers to the Hella connection. ".... "AGTAR has acquired the regulator business from Hella." Hella itself no longer offers this system (neither in Germany nor abroad). Since the manufacturing is done by a well-known small manufacturer, it is not a problem to change the seller (now AGTAR).

Hi Bertil,

Yes, that was quite a few years ago, but I also wrote it like that.
I, of course, didn't know the current status of HPR production, but now I'm up to date again.
"I can scan the charging characteristics of the HPR controller; they are described quite well in the accompanying manual. I bought the HPR mainly because of its large onboard battery capacity, not to protect my starter battery. There's a significant difference depending on the charging curve the controller uses when you want to pump 80Ah into your battery. And in a campervan, it's quite normal to drive for 4 to 5 hours continuously, so the onboard battery can also benefit from the IU°U charging curve. And I'm very interested in knowing whether I can charge my onboard battery to 90% or 98%!" Anyway, everything is completely different compared to a "normal car" .

Regards,
Jens.

Could you please check the Bosch catalog for starters and alternators? The regulators are explained there.



by the way:

1,987,720,011 is the lucky number (of the catalog).


By the way, the temperature coefficient is also listed in the document.

@ulf
Emergency regulation.
If the battery sensor line is interrupted, or if there is an increased voltage drop (>1 V) on the B+ charging line, the regulation will automatically switch to B+ from the generator.

CU Gremlin.

But then I start having bad thoughts: 'What happens if the thick B+ cable has a loose connection?' -> Then, in my opinion, the alternator voltage would run up unregulated, and the diodes might fail due to exceeding the reverse voltage, voltage spikes, etc. icon_eek.gif icon_question.gif

How does the µcharge system react to such errors?

@ ulf: Yes, you have to be careful not to cure one problem by creating another. However, you shouldn't overestimate certain error rates either. If you just haphazardly fiddle with a cable, or carry around a huge mess of wire connectors, then you shouldn't be surprised by any failures. If you install things carefully and secure the cables according to regulations, then, realistically speaking, there is only a negligible risk that a cable will be interrupted. If that were to happen, the charging current would increase to its maximum, and the battery would heat up. In my experience, the on-board voltage then rises to values of up to 16.5V, and the battery happily starts to bubble. While a power surge won't damage anything in the vehicle's electrical system, it's certainly not good for the battery. MicroCharge chargers don't operate differently in this regard compared to all other chargers: if the output voltage drops, the pre-excitation increases, and consequently, the power output of the alternator increases. I consider it uneconomical to include a separate circuit to handle the case where the sensor cable is disconnected. You could practically implement an unlimited number of safety measures, but hardly anyone notices, yet everyone has to pay for them.


...I bought the HPR primarily because of its relatively large onboard battery capacity, not to spare my starter battery. There's a very noticeable difference when you want to pump 80Ah into your battery, depending on the charging profile the regulator uses. And in a campervan, it's perfectly normal to drive for 4 to 5 hours continuously, so the onboard battery can also benefit from the IU°U charging profile. And I am very much interested in knowing whether I can charge the onboard battery to 90% or 98%!

@ Jens: Hi Jens. I'm interested in knowing what the charging voltage is for the 'HPR' regulator. After all, an IUoU-type regulator for charging lead-acid batteries is characterized by a significantly higher voltage level compared to normal regulators. It is precisely this increased state of tension that makes it necessary to reduce the charging voltage to a level that is tolerable for an extended period of time after the battery has reached its full charge.

Several tricky problems arise when operating IUoU (Intelligent Unit of Operation) and similar software-controlled regulators in motor vehicles:

How does the regulator determine the battery's state of charge? The designs I am familiar with are, for various reasons, not capable of doing so, especially in the environment of a vehicle's electrical system. They cannot use the onboard voltage after the maximum generator current is exceeded, because it corresponds to the control voltage (predictably). They cannot determine the battery charging current, because it can only be measured by the regulator together with the load current of all onboard consumers. What remains? A time-based shutdown? Oh dear, that is - to put it mildly - really not optimal...
For understandable reasons, the on-board voltage is only allowed to vary within relatively narrow limits (approximately 13.5 to 14.7V). If two different voltages are determined for the charging phases 'fast charging' and 'maintenance charging,' approximately 0.5V of voltage fluctuation range is already lost, which is then no longer available for compensating for temperature fluctuations.
How does the regulator determine that the battery's state of charge has decreased after a full charge cycle? As mentioned above, the regulator has no way to perform its own measurements. Does it simply charge with a reduced charging voltage after switching from the 'IU-' to the 'U' charging curve? This question may initially seem purely academic, but it is not when considered more closely. There are many common driving situations in which the power consumption of the vehicle's electrical system significantly exceeds the power output of the generator. Stop-and-go traffic under heavy load is a typical and (unfortunately) often experienced example. If the charging voltage of the generator is significantly below the values required for rapid recharging, the state of charge of the battery will decrease.
I certainly don't want to criticize the regulator mentioned. However, I don't believe it's suitable for use in cars or campervans. In fact, I think using such regulators in cars is more likely to be harmful, because a lot of unforeseen things can happen that you simply can't anticipate. It's not that simple, and the devil is often in the details. Unfortunately, these problems often only become apparent later, through inexplicable issues during operation. However, these types of regulators are definitely useful in boats, which have long engine running times. There's no stop-and-go either...

If you could measure the charging voltage, that would be very informative.

Best regards, Tom.

Okay, I've done some measurements on my Polo to assess the potential benefits of a system similar to µcharge.

I used a laboratory power supply to push 5 amps through the B+ line, from the alternator's terminal to the battery terminal.

The voltage drop (measured at the cable, not at the power supply terminals) was 8.3 mV over the entire length, including the 175A fuse.

At full LiMa (alternator) output of 90A, the voltage drop would be approximately 8.3 mV * 90A / 5A = around 150 mV.
And in my opinion, the effort required to directly connect the regulator to the B+ terminal isn't worth it to eliminate those issues.

By the way, I also measured the current flow path. A current of 5A between the alternator and the battery resulted in a voltage drop of 4.8 mV.
However, the non-charging current in the 9N doesn't flow "through the battery negative terminal" but branches off into the car body – but even at that point, about 3 mV are lost, which means an additional 50 mV at 90 amps.

Would these also not be compensated for by a µcharge regulator - or am I mistaken?
While he (correctly) connects to the weakest link = the B+ line, but because of at worst 0.15 V too little charging voltage, my Polo probably won't become a candidate for overheating and stopping. . .

I used a laboratory power supply to push 5 amps through the B+ line, from the alternator's terminal to the battery terminal.

The voltage drop (measured at the cable, not at the power supply terminals) was 8.3 mV over the entire length, including the 175A fuse.

At full LiMa (alternator) output of 90A, the voltage drop would be approximately 8.3 mV * 90A / 5A = around 150 mV.



um...
Have you worked with high-current technology before, or not?

Let's try setting it to 90A and measure it again...

CU Gremlin.

Hello fellow diesel enthusiasts.

I'm somehow surprised that the batteries in our tractors are 11 years old.
were. And this, with electromechanical controllers!
If the batteries had known

Best regards, chrigu.

Gremlin wrote:

um... Have you worked with high-current technology before, or not? Let's try running 90A and take another measurement...

What fundamentally different result would one expect compared to what my calculation yields, and why?

Do ohmic resistors behave non-linearly in the 2-digit ampere range ?

Providing a somewhat constant power supply would be feasible by running the alternator at its 100% load, even at idle, by connecting various power-consuming devices to it. This would be noticeable by a drop in the on-board voltage below +14V.
Unfortunately, I don't know how many amps the battery will deliver.

And currents > 20A, I cannot measure.

Hello, diesel enthusiasts.

I'm somehow surprised that the batteries in our tractors are 11 years old.
were. And this, with electromechanical controllers!
If the batteries had known

Best regards, chrigu

Hello chrigu,

This is likely due, for the most part, to the lack of battery charging from external power sources in agricultural machinery. When you look at modern vehicles, it's surprising that the batteries even last a year when drawing current from external sources in the hundreds of milliampere range. Therefore, it's all the more important that the batteries are recharged as quickly as possible while the vehicle is in operation. For this reason, vehicle manufacturers are equipping models with a lot of electronics with more powerful alternators, and the voltage regulators generally operate at around 14.3 volts instead of the previous 14 volts. This has less to do with the increased current consumption during operation and more to do with the electronics that inevitably drain the battery when the vehicle is stationary. Unfortunately, this doesn't really help for people who drive very little (e.g., housewives) or for those who drive a lot (e.g., taxi drivers). In the former case, the batteries are usually hopelessly discharged, while in the latter case, they are severely damaged after only half a year. MicroCharge charging regulators are recommended specifically for these extreme cases. Those for whom everything is fine should avoid spending the money. And for old tractors, I don't think that MicroCharge chargers would be particularly suitable there...





'...Using a laboratory power supply, I forced 5 amps through the B+ line, from the alternator's terminal to the battery terminal.' The voltage drop (measured at the cable, not at the power supply clips) was 8.3 mV across the entire length, including the 175A fuse strip.



Then the resistance is R = U/I, which is 0.0083 V / 5 A = 1.66 milliohms. With a maximum current of 100 A, this would result in a moderate 166 mV. So, with such a small voltage drop, it's not even worth thinking about for very long. This is absolutely completely harmless.

However, I do have doubts about whether the measurement is actually correct. I have never even come close to experiencing such a low resistance, especially not when a fuse was included in the circuit. 'How long is the measured cable, and what is its approximate cross-sectional area?'

Greetings, Tom.

Do ohmic resistors behave non-linearly in the 2-digit ampere range ?


Yes, because there is a significant amount of warming occurring in some areas.
keyword: FUSE. Try applying a 90A load to it after a few minutes...

With such high currents, the contact reliability is also crucial. For example, if a ring terminal doesn't make proper contact, the initial resistance may seem acceptable. However, at high currents, the current doesn't distribute evenly across the surface, leading to a high current density at the contact points. This results in significant heating, with all the known consequences. Similarly, the crimping of cables can be affected...
You won't be able to handle that with a 5A level.
'You're getting great readings with that MR meter, but if you ever let 250A pass through...'


@chrigu

Your old tractor has a nearly ideal performance profile.
No standby power consumption when idle. After startup, typically long operating times. Usually, one spends almost the entire day in the field.

CU Gremlin.

Diesel wrote:

Then the resistance is R=U/I, which is 0.0083V/5A = 1.66 milliohms. ... However, I do have doubts about whether the measurement is actually correct. I have never even come close to experiencing such a low resistance, especially not when a fuse was included in the circuit. How long is the measured cable, and what is its approximate cross-sectional area?

According to SLP, 16 mm², estimated length ~ 1 meter.

Copper has a specific resistance of approximately 17 micro-ohm x mm²/m, if I recall correctly.
Calculating based on 1 meter and 16 mm², the result would be 1.06 mOhms.
I measured each fuse individually, and the result was 1.8 mV/5A, which corresponds to 0.36 milliohms.
-> The calculated value of 1.42 mOhm is actually quite good compared to the order of magnitude(!) of the measurement.

I have, by the way, resoldered all the positive and ground crimp connections in the power path between the alternator (LiMa) and the battery using two 100-watt soldering irons (which, working together, can even handle the 30 mm² cable to the starter ), and I protected all the screw connections with grease to prevent corrosion, when the car was only a few weeks old.
Perhaps that explains the "unusually low" resistances (at least as long as they are measured in the low-ampere range) .

Diesel wrote:

The "L" terminal simply switches from a ground potential to a positive potential when the generator is started. This allows you to switch loads, but not to take any measurements. The wiring diagram of modern controllers makes it clear what I mean.

Sorry for the delayed response.

Then I still wonder what triggers the regulator to switch from standby to operating mode... in any case, the current draw via B+ with the engine off is practically zero.

Could the L-Pin, when in standby mode, also be used simultaneously as an activation signal (unlike in the circuit diagram)?
Okay.
L = low and no AC signal on terminal V -> Standby.
L = high -> initiates external activation of the standard operating mode.
Signal to terminal V -> activates the internal control mode, where input L is ignored and only functions as an output.

Hello Diesel,

First of all, as a reader of this forum, I find it positive when you contribute expert information here. I don't see this as unwanted advertising. I do, however, have some questions and comments.


- Your regulator only has a sensor on the positive (+) line; it does not compensate for voltage drop on the negative (-) line. 'It's certainly smaller, but in my case, the Lima (alternator) and battery are located right next to each other, and the positive and negative cables are roughly the same length.'

- I would definitely consider what would happen if the sensor cable were to break. If the voltage then rises uncontrollably, the damage could far outweigh the benefits of the device. I can certainly imagine that some workshops might simply overlook it (after all, such a thin wire can't be that important... well, you should have told us beforehand that you had such a special regulator in there...).

- At low temperatures and with poor wiring, the voltage can increase significantly. I once heard from a VW workshop master that, in some vehicles, the electronics start to malfunction when the voltage exceeds 15V. Regarding your regulator, the electronics should be connected to the battery and not to the alternator (I don't know if this is the case for every vehicle). Additionally, I would recommend installing an extra limiter to prevent the voltage at the alternator from exceeding 15V.

- The Hella HPR has a weaker temperature dependence.

below -10°C 14.4V 15.0V
-10 to 10°C 14.2V 14.8V
10 to 30°C
14.0 V
14.6 V
below -30°C, 13.8V, 14.4V

(The Hella HPR switches between two voltage levels, and Jens once posted a guide online; I can share that if needed.)
Currently, various processes are taking place within the battery, each with different temperature dependencies. What parameters does your controller use as a reference? Are you talking about gassing?


(Yes, yes, nowadays even our European engineers are 'thinking outside the box' and using a single transistor to perform at least two functions...). What I mean is that the regulation isn't exactly a paragon of precision. But still: They do serve their purpose.



- I suspect that the standard alternator regulators have a non-negligible apparent internal resistance, meaning that (just to give a few numbers) when drawing 100A, the alternator no longer regulates to 14V but to 13V, which would indicate an apparent internal resistance of 10 milliohms. That sounds like very little, but it means that at high loads, the battery is no longer being charged, even though the alternator could still supply the current. I've always wanted to measure this myself, but I haven't gotten around to it yet. If you install thick charging cables, you can easily keep the cable losses below 10 milliohms, but that won't help. Do you know how standard alternators behave? How does your regulator behave? If it had a lower internal resistance, that would naturally result in better battery charging. I don't know if such a low internal resistance would have any drawbacks (e.g., regulator oscillations).

- In campervans, you usually have a starter battery and a supply battery. The latter is powered by a relay. However, this is not ideal; shunt diodes are better, one between the alternator and the battery. The disadvantage is the reduced charging voltage due to the diode voltage. Your regulator might be able to compensate for this. It would be interesting to know whether it is compatible with Schottky diodes.

- In an IUoU characteristic curve, the question arises as to when the switchover between the two voltages should occur. Sterling Company.

'They claim that their controllers can calculate this. However, the principle by which this is achieved remains unclear. Hella (and Agtar) take a different approach; in this case, the controller switches on and off according to a fixed time schedule.' This is certainly not ideal, but it's probably better than nothing. That means there must be a way to find a schedule that avoids negative influences, while still allowing for a somewhat faster (though not the fastest possible) charging process.



Especially in cars, motorhomes, or commercial vehicles, charging times are rarely long enough for an IUoU charging profile to be particularly beneficial. The regulator is almost exclusively involved during the UI phase.


It largely depends on the usage patterns, but if the regulator were almost exclusively in the IU phase, the battery would only be charged to about 2/3 capacity, which would likely shorten its lifespan considerably. I think, therefore, that the battery is often operating within the UoU (Use of Utmost) range.

Hello.
Wolfgang.http://www.german.sterling-power.com/html/lichtmaschinenregler.html{MARKER}http://web1.tcserver2.de/handbuch/HandbuchNeu/T203/seite2.htm{MARKER}

Wolfgang, syncro16 wrote:

I suspect that the standard limiter regulators have a non-negligible apparent internal resistance, meaning that (just to give a few numbers) when drawing 100A, the alternator no longer regulates at 14V but at 13V, which would indicate an apparent internal resistance of 10 mOhms. . . . Do you know how standard alternators behave? How is your regulator behaving?

Even though I'm not a diesel engine:

A controller essentially has very little (significant) internal resistance and is essentially just a threshold switch, with a small amount of hysteresis to prevent oscillations or undefined switching states.

He rapidly switches the excitation current on and off (U = charging voltage).
Uist <Usoll> Pathogen ON
Uist > Usoll -> Pathogen OFF
As a result, the charging voltage (which is the feedback variable) oscillates in a sawtooth pattern with a small amplitude around the target value.

If the alternator needs to supply more power, the charging voltage (theoretically) decreases, but the regulator responds by increasing the excitation time (ON time) and decreasing the OFF time (because the voltage drops faster under heavy load) -> the desired voltage (Usoll) is maintained, as long as the alternator's speed, its load, and its ability to supply current allow it.

Practically, a fully functional lithium battery within these limits has an internal resistance of zero.

Hello Ulf,

If the control circuit is properly designed, the internal resistance can certainly be minimized. The question is whether that was done here; if I read that transistors are being used for two functions to save costs, and 'temperature compensation' is only a byproduct, then I have my doubts. It's also possible that an internal resistance is intentionally added to circumvent problems that a more precise regulation might cause.

I've just noticed that the Lima switch posted by Diesel above works differently than older designs. It used to look like this.

[img][/img]

'I borrowed the picture from Michael K. In this diagram, there's a separate section labeled 'excitation diodes' that generate the D+ terminal, to which the charging indicator light is connected (terminal L in the other picture). The regulator only controls the voltage at D+! However, the load current flows through B+, meaning that the additional voltage drop caused by the load current at the diodes is NOT compensated for.' Here, the microcharge could potentially offer an additional benefit.
In the other picture (of the diesel engine), the adjustment is made at terminal B+, which is how it should be.

Okay, so now the question for me is, what exactly do I have in there? (It's an alternator from a Golf 3, year 1996, with a 120A Bosch alternator, part number 0 986 041 300 according to ECAT, and regulator 1 197 311 530). Does anyone know anything about it?

Hello.
Wolfgang.http://vwbus.dyndns.org/bulli/michaelk/vw_bus_d/drestrom.gif{MARKER}

Wolfgang, syncro16 wrote:

The regulator only controls the voltage at D+! However, the load current flows through B+, meaning that the additional voltage drop caused by the load current at the diodes is NOT compensated for. Here, the microcharge could potentially offer an additional benefit. In the other picture (of the diesel engine), the adjustment is made at terminal B+, which is how it should be.

Yes, that might be a cause of the "higher internal resistance" of LiMas with separate excitation diodes.
So the question is, how much does the voltage at B+ fluctuate between low load and full load, while it remains constant at the excitation terminal.

I once removed the alternator from my 1997 AFN engine and lubricated all the connections in the regulator area to prevent corrosion. Unfortunately, it's been so long that I no longer remember whether it has zener diodes or not.

Probably yes, because I don't remember any such "wow" effect like with the Polo alternator, which, as mentioned, no longer has any excitation diodes.


@Diesel:
What are the typical ranges of lead resistances that you have measured so far?