Erfahrungen mit dem Laderegler "microcharge" | Posts 48+

- 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.'


Of course, that would be possible, but it would then create certain technical problems with the 'grounding' of the battery and generator via the regulator. Furthermore, the voltage drop on the negative side is usually significantly lower than the voltage drop on the positive side, which is why I decided not to include it.


- 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...).


'MicroCharge' probably isn't directly comparable to a 'bullhorn festival.' I must also admit that this product isn't exactly sold in blister packs at supermarkets, and understanding its function, as well as its assembly, requires some technical knowledge. However, a workshop wouldn't simply cut or omit this cable, because first, it runs directly from the temperature sensor on the battery to its positive terminal (making it quite visible), and second, workshops generally don't leave anything out during reassembly, because doing so would constantly cause problems with components whose function they don't understand. Since the sensor cable is firmly attached to the battery terminal stud with a ring terminal that is screwed in, you would need to completely unscrew at least the screw of the terminal before you can remove the cable. There must be intent involved here.

However, even if the alternator is running at full power, the battery would limit its voltage. In reality, the voltage can't rise much above 16V, because the battery would start to overheat significantly, which would be noticeable by the smell. If I were to now implement a kind of 'failsafe' function that, for example, would regulate based on a voltage difference of approximately 1V between the alternator's B+ terminal and not the battery's positive terminal (which would be very cheap to implement), it would deprive the regulator of its ability to compensate for voltage drops caused by isolation diodes and similar components that are above this value. What you gain in safety on one hand, you lose in terms of functionality and practical usefulness on the other. But try explaining that to the average website visitor... I could adjust the settings so that voltage differences of more than 1.5V are considered errors and corrected. Then, the average regulated voltage would no longer be 14.1V, but rather around 15.6V. The question arises whether one would have really gained anything with it.


- 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.


'So, the on-board electrical system should function perfectly and without any issues up to at least 17V, according to the design specifications. The on-board system is essentially always connected to the battery, but never directly to the generator. Sometimes the generator might be connected to the starter cable, but the on-board system primarily relies on the battery. Furthermore, a generator voltage of 15V would be far too low to ensure proper regulation. With 5 meters of cable and a blocking diode between the generator and the battery, a voltage of 16.7V can easily occur at the generator when 14.7V is required at the battery (in cold conditions) and with a high charging current! If the generator only produced 15V, only 13V would reach the battery.' The result would be a tired shrug from the ship's electrical department.


- 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).


Vehicle alternators essentially have no internal resistance, especially when the regulator is functioning ideally. It's important to understand that the load current does not flow through the regulator; instead, the regulator only controls the power output of the alternator. It does this by ensuring that the target voltage is always reached. This is similar to driving a car at 100 km/h and using the accelerator to maintain a constant speed on inclines or declines. The current that the regulator allows to flow through the excitation winding of the alternator changes the magnetic field of the alternator's rotor. Proportionally, this changes the induced voltage in the stator winding of the alternator. The advantage of this type of regulation is that the very high generator current of 50, 100, or even more amperes does not need to be 'regulated' directly, but only the small pre-excitation current, which is between 0.5 and 2A, is regulated indirectly. These small currents are much easier to control technically. Of course, this says nothing about the actual performance of the generator regulator itself, and there are significant differences in that regard. Standard regulators can fluctuate by as much as 0.7V, which results in a load regulation of +/-0.35V. With the MicroCharge regulators, I made sure that the regulation factor is so low that it does not exceed +/-0.1V. This is important for several reasons, because the voltage changes significantly due to temperature compensation, and I don't need any additional voltage fluctuations that could potentially cause the voltage to exceed the permissible range.

- 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.


Here, the issue of voltage limiting, which we discussed earlier, becomes apparent. Since MicroCharge chargers regulate based on the effective battery voltage, the voltage drop between the alternator and the battery is not a significant factor. MicroCharge adjusts accordingly.

'But I'm already having a bad reaction just thinking about using blocking diodes. Please don't include such junk in your designs! The current dependency of the voltage drop across diodes *always* causes endless problems. Even the best regulator won't help in that case. You have to remember that, because of the voltage drop across diodes, you always need to install two: one for the power supply circuit and one for the vehicle circuit.' And now, here's what happens:


- 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 that. However, the principle by which it works remains unclear.


Unfortunately, this can't be calculated so easily. The controller can switch based on voltage, or on time, or on an algorithm that combines both. According to Murphy's Law, it's always wrong. Conclusion: Suitable for boats, not for cars.


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.


Here's the translation:

That's the incorrect assumption: If the IUoU charger operates at 14.6V during the 'IU' phase and at 14V during the 'U' phase, and if it continues to operate in a time-controlled manner, for example, always running the IU phase for one hour and then switching to U-charging, then it becomes clear that after each engine start, the charger will charge at 14.6V for 60 minutes, regardless of the battery's state of charge! And if the engine is briefly turned off, then the IU phase will even restart, causing it to charge and overheat, charge and overheat....

Let's stop sugarcoating it: UPS systems and certain boats might find them useful, but definitely not for cars or campervans.


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


Jupps: You installed the older version with the wiring as shown in your picture. The regulator actually adjusts based on the voltage level at 'D+', not at 'B+'. However, what is much more serious is the fact that regulators with the BOSCH part number you posted have a regulated voltage of 14.5V. This seems not only too high, but even much too high. What does your battery say about this? Have you ever measured the voltage?

Best regards, Tom.http://www.microcharge.de/w124/forward_voltage.gif{MARKER}http://www.german.sterling-power.com/html/lichtmaschinenregler.html{MARKER}http://web1.tcserver2.de/handbuch/HandbuchNeu/T203/seite2.htm{MARKER}

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?

Diesel wrote:

The regulator actually orients itself to the voltage level at "D+", not at "B+". However, what is much more serious is the fact that regulators with the BOSCH part number you posted have a regulated voltage of 14.5V. That seems not only too high to me, but even much too high.

According to Grem's list, the regulator also has a temperature coefficient of 10 mV/K.
This raises the initial question of the "reference temperature" for the 14.5 V.

The unregulated voltage drop across the main diodes must also be taken into account.
If the in the middle of all loads , for example, consume 0.2 volts more than the excitation diodes, the alternator would effectively regulate to approximately 14.3 volts at the B+ terminal.

In addition to the already discussed voltage drop caused by the cable on the way to the battery, the charging voltage there will, in my opinion, be "significantly" below the regulator voltage - although it unfortunately also exhibits certain load-dependent fluctuations.

Quote:

The unregulated voltage drop across the main diodes must also be taken into account: If the alternator, on average, consumes, for example, 0.2 volts more than the excitation diodes, the alternator would effectively regulate to approximately 14.3 volts at the B+ terminal.

I would see that differently. Not all diodes are the same. The higher voltage drop across the diode, which depends on the load, is a result of the forward resistance of the diode. Diodes designed for higher loads have a lower forward voltage drop, so it is quite possible that (with appropriate selection of diodes) the voltage drop across the excitation diodes and the power diodes is the same, because a higher excitation current must flow with higher power.

Greetings.
dieter

dieter wrote:

Diodes for higher loads have a lower forward voltage drop, therefore it is quite possible that (with appropriate selection of the diodes) the voltage drop across the pilot diodes and the power diodes is the same, because with higher power, a higher pilot current must flow.

Yes and no... For a fixed, constant speed of the linear motor, it would probably be possible to achieve that with almost perfect precision.

Since the power output also depends on the speed, a higher (effective) excitation current must be applied at low rpm to achieve a specific charging current.
-> Higher voltage drop across the excitation diodes causes the regulator to "boost" to compensate, which increases the voltage at B+ (with unchanged load), the lower the alternator's speed.
Conversely: If you give it more gas, the voltage at B+ decreases.

But I think these unavoidable "errors" should be in insignificant magnitudes, if you have ensured equal voltage drops through a suitable combination of source and load diodes, essentially "eyeballing" it.

Or were the B+-controlled regulators developed because the remaining errors are not so small ?

three T3 Syncro 16" vehicles with AFN engines in one thread, and it doesn't even have anything to do with diesel engines or VW...
It's not relevant, but I find it remarkable .
Best regards to Dieter and Wolfgang .
Jens.

Sure, here's the translation:

"PS:"
I can't seem to find the documents from HPR right now (due to a move), and my publication from that time has also gone missing. Wolfgang, if you still have that, please post it here.

Hello Diesel,


What is even more concerning is the fact that regulators with the BOSCH part number you posted have a regulated voltage of 14.5V. This seems not only too high to me, but even excessively high. What does your battery say about this? Have you ever measured the voltage?


'So, originally, I had a different alternator installed. It was measuring 14.0V, which seemed a bit low to me. I have a feeling that my house batteries are sulfated, but I haven't done a capacity test yet, although the Megapulse is already ready to go. That's why I was actually quite happy when I measured 14.4V with the new alternator. To my knowledge, that's a normal charging voltage for a lead-acid battery, and if it's applied for 1 or 2 hours, it shouldn't harm a fully charged battery. If it happens more frequently, you need to add some water. However, if the 14.4V is present around the clock, it will reduce the battery's lifespan.' So, in buffer mode or when the battery is constantly connected to the charger, you need to reduce the voltage to 13.8V. Here are the recommended charging guidelines for Exide Gel batteries:

It is recommended to charge for 12-16 hours up to 14.4V, so whether it's 4 hours more or less doesn't really matter; and flooded batteries are generally more tolerant of charging errors because you can always add water.
And that's why I'm going to check the fluid level tomorrow.

Here's the 6-page information sheet for the Hella HPR; it switches between charging modes, with 2 minutes at 14V and 12 minutes at 14.6V, resulting in an average of 14.5V, with a pause of approximately 2 hours.

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[/img]http://www.exide-automotive.de/produkte/gel/anwend_ber.html#ladetechnik

Thank you for your detailed answer, and thank you to Gremlin for the information.

Hello.
Wolfgang.http://home.t-online.de/home/wonic/bilder/Hella_Power_Regulator_1.gif{MARKER}http://home.t-online.de/home/wonic/bilder/Hella_Power_Regulator_2.gif{MARKER}http://home.t-online.de/home/wonic/bilder/Hella_Power_Regulator_3.gif{MARKER}http://home.t-online.de/home/wonic/bilder/Hella_Power_Regulator_4.gif{MARKER}http://home.t-online.de/home/wonic/bilder/Hella_Power_Regulator_5.gif{MARKER}http://home.t-online.de/home/wonic/bilder/Hella_Power_Regulator_6.gif{MARKER}

Hello,

More recent lead-acid batteries have a chemically purer lead content (e.g., less antimony) and can therefore withstand higher charging voltages than older batteries.

Sincerely,
Christian

Hello,

More recent lead-acid batteries have a chemically purer lead content (e.g., less antimony) and can therefore withstand higher charging voltages than older batteries.

Sincerely,
Christian

Hello Christian,

Where can I find more information about this thesis? I haven't heard of it before. I am particularly interested in the physicochemical explanation of why newer, antimony-free lead-acid batteries can tolerate a higher charging voltage.

Does this statement refer solely to the replacement of antimony with calcium and the associated reduction in water consumption?

Best regards, Tom.

Hello Tom,

Here's a page [url] already, [/url] under 3.

A problem with high charging voltages is the gassing (formation of explosive gases) of lead-acid batteries. This is the cause of water loss. Can I reduce the gas generation? If so, would that allow for a higher charging voltage?

A standard battery from 1970 wouldn't last long in today's 14.5V, 100+A vehicles.

Sincerely,
Christianhttp://www.varta-automotive.com/de/index2.php?p=4&s=3&content=knowhow/batterielexikon/entwicklung.html{MARKER}.

Hello Christian,

The issue with water consumption is clear. But what about the risk of lattice corrosion with high charging voltages? I am familiar with the VARTA website, but I haven't found any relevant information there (I last checked it about 6 months ago).

Greetings, Tom.

Hello Tom,

"These voltages would not really be suitable for continuous charging. However, a car, over its lifespan, is used for relatively short periods. Approximately 8760 hours per year. 1000 hours of highway driving corresponds to roughly 40,000 to 80,000 kilometers. Therefore, the charging duty cycle of a typical driver is more likely to be in the range of 1:10 to 1:100." A slight increase in the state of charge (SOC) of the lead-acid battery, even when caused by a relatively high charging voltage, has a much greater lifespan-extending effect than the slightly increased grid corrosion that occurs during charging at voltages above 14V.

Sincerely,
Christian

I haven't heard anything about a connection where calcium-alloyed lead-acid batteries handle overcharging better than antimony-alloyed ones. To my knowledge, the grids of calcium-alloyed batteries also crumble under overcharging conditions, just like those with antimony in the alloy. This would mean that the aforementioned 'overcharge resistance' advantage of cells primarily alloyed with calcium would be solely based on the reduced water decomposition. The disadvantage, however, is that most 'maintenance-free' batteries no longer have removable vent plugs. These would be necessary, at the very least, when working with higher charging voltages. The water supply is usually already degraded before the grid corrosion causes the plates to crumble. Therefore, I do not see that maintenance-free lead-acid batteries are inherently more resistant to overcharging than standard batteries with a 2% antimony additive (which, incidentally, significantly improves cycle and deep discharge resistance). Under normal circumstances, you simply don't need to refill the water. Oh, and: The self-discharge rate of calcium-alloyed lead-acid batteries is usually also lower, but conversely, the tendency for acid stratification is higher, and the cycle life is also worse ('antimony-free effect'). It turns out that everything has its advantages and disadvantages, even before and after .

Ultimately, it all comes down to ensuring that all parameters are within the acceptable range. Undercharging is bad, but overcharging is just as problematic. Of course, a few overcharges during prolonged periods of undercharging won't cause much harm. Conversely, the same applies in the other direction. Discussing this in detail might be somewhat academic. However, since the current demand of modern vehicles, even when stationary, now exceeds 50mA, even occasional overcharges are no longer sufficient to recharge the battery. This is the real reason why increasing the charging voltage of modern vehicles to an average of 14.3V only extends the lifespan of the starter battery by a little over two years. Because the high charging voltage begins to damage the cells through water consumption and grid corrosion, even though the sulfation, which occurs due to prolonged discharge, has not yet been reduced. Only by finding a better balance between charging voltage and wear than previously achieved can we significantly increase lifespan and reliability. In my opinion, simply increasing the charging voltage alone will not really make a significant difference.

Greetings, Tom.

Hi,

Now it's my turn to chime in. In my professional life, I sometimes deal with internally approved 48V power supply systems for telecommunications equipment, as mentioned earlier.

Here, great importance is placed on temperature-compensated charging, because the installation locations are almost always not air-conditioned, but the batteries still need to achieve the longest possible lifespan. Typically, OPzV or OGi batteries are used, which, according to the Eurobat guidelines, are designed to have a lifespan of 10+ years, at least under normal conditions.

The temperature-compensated charge of power supplies approved for use in our region is, in any case, based on the characteristic curves specified by the battery manufacturer. The battery manufacturer provides this data as a dataset to the power supply manufacturer. The values can differ by several percentage points. Only a few battery manufacturers are authorized to provide this data.

How can a third-party manufacturer of a car alternator take this into consideration? There are countless types of batteries available on the market.
"In my opinion, approximate values should already be used here, just like with the standard charger controller, and these values cannot represent the optimum."


"Furthermore, I am shocked by this statement:"

Quote:

So, the on-board network should function perfectly and without any issues up to at least (!) 17V. That is, at least, what the construction regulations state.

On the Osram website, for the design of automotive light bulbs, ECE R 37 is cited, which specifies a nominal voltage of 12 V and a design voltage (an outdated term) of 13.2 V or 13.5 V.

"Quote from Osram.de:"

Quote:

Question: Why not increase the design voltage for lamps to 14 volts, for example, to avoid lamp failures, especially in new cars that often provide relatively high voltages? Sure, here is the translation of the text from German to English: "Antwort:" "Answer:" Because the European standard ECE legally mandates a design voltage of 13.2 volts for headlight bulbs and 13.5 volts for auxiliary lights. A change to the design stress is only possible after a change in the relevant standard. The current demands on lamps from the automotive industry can be better met with designs that use relatively lower voltage levels.

How does the ECE regulation address the mentioned 17V?
Even with a slight increase in voltage, the lifespan of incandescent light bulbs decreases dramatically, to a fraction of its original value.

Of course, different lead-acid batteries also have different charging recommendations from the manufacturers, although the characteristics of similar types are already very similar. These can only be approximated by a universal product. Nevertheless, even an approximate temperature compensation is almost always more beneficial than no compensation at all. In addition, the charging voltage of the MicroCharge charger can be adjusted as needed, allowing for a more precise adaptation to the specific requirements. However, the compensation curve remains the same; it is only shifted by a fixed voltage amount. Since MicroCharge is practically exclusively used for wet-cell starter batteries, the charging curve is already extremely limited. Even when using Optima round cell batteries, the compensation curve is still applicable.

The note regarding the specification of 10.5V to 17V, of course, does not apply to standard light bulbs. That would be asking too much, because, naturally, an incandescent bulb will emit a different amount of light at 10.5V compared to 17V. Nevertheless, certain tolerances must be allowed in the voltage supply, and this mainly affects the electronics. In particular, safety-critical electronics such as ABS, ESP, and all restraint systems must function flawlessly up to at least 17V. I mention this because there have been repeated concerns that airbags might explode unexpectedly if a voltage regulator varies the charging voltage between 13.6V and 14.7V. That was all there was.

Greetings, Tom.

Hello everyone,

Okay, first of all, let's talk about the voltage limits of the safety systems and the motor control electronics.
These also function perfectly well with voltages above 15V, of course! However, this puts a great deal of stress on the components, which reduces the lifespan of the control units.

Now, let's talk about the charge controller:

Since the regulator likely doesn't have an EC approval, installing it will void the car's operating permit. That means there is no insurance coverage.

It wouldn't be a problem for the controller manufacturers to integrate such a 'battery temperature' measurement into the controllers.
However, reliability is extremely important in the automotive industry!

The controllers must function perfectly within a temperature range of -40°C to +120°C, as well as in a humidity range of 0-100%. In the event of a cable break, the voltage must not reach its maximum; instead, the regulator must shut down.

Before a regulator is approved, a number of tests are required, including a continuous operation test at maximum power for at least 1000 hours, several thousand temperature cycles from +120°C to -40°C and back.


Best regards, Uncelsam.