Will a Larger Battery Than OEM Cause Undercharging in Opel Astra With Parking Heater?

13,5v

Hello. To my colleague Brys: Simply at frequencies of the kilohertz range, and alternators operate at such frequencies, there is the so-called skin effect of the current flowing in the wires, and you gentlemen use the CORRECT formulas, but for direct currents.
Here my friend has clearly gone astray. At 6000 rpm, the frequency of the three-phase current will be 100 Hz!
To my colleague Felekala: A rectifier without automation, like the alternator, does not provide constant voltage charging. It is best to establish a tap for the initial charge, not exceeding the allowable current, and after initial charging, reduce the voltage so as not to exceed 14.4 V. Setting only the second one will unnecessarily extend the time.

Colleagues, and the car is constant voltage charging, not DC charging as you suggest.
Recharging by 0.5V of a 90Ah battery lasts almost twice as long as 45Ah, because the charging current depends on the voltage difference between the alternator and the battery and the resistance of the charging circuit (alternator + battery)
The alternator can give 100A but the battery will take as much as the Ohm law allows.
The driving time for each start-up is important in this case.

Generally, the new alternators on new MID-CLASS cars are lame.
It is better in more expensive ones.

Added after 1 [minutes]:

GBW note that the battery has a voltage of 14V and it is charged with a current depending on the degree of discharge.

Enough of these deliberations - it was already discussed on the forum more than once. I close.

And I am wondering whether to change 75Ah to 100Ah, contrary to what is written here, what if I have a 100A alternator, since it is not a good solution and it is better to charge the battery with a rectifier.

I can only see here the advantage of the larger one over the smaller one, that with the engine off, you can listen to music longer without fear that the battery will not fire because it will run out too much.

I had a Skoda Octavia 1.9 tdi car, and during an alternator failure, the mechanic replaced the entire regulator. After this replacement, the alternator was supposed to reach 120 A. After connecting it on a test bench, it reached a value of 135 A. I also installed a 90AH battery. For the next 10 years I didn't know what a battery problem was. There were different trips in the taxi, long and very short, and frequent starting of the car. These 135A were measured on a test bench and there were no philosophical formulas.

The only question is what kind of battery is it? Because I doubt that today, even with great charging, a working car, etc., it would last 10 years.

(Nice reheat.) )

My friend neverever A friend of mine is trying to raise awareness of those fighting against windmills, but he is plowing the fallow land. I have been expressing myself in a similar style for at least a dozen years, to no avail - the myths still persist. I had similar problems when purchasing a new larger battery.
For those who don't believe, the little ones (I had two of them with generators) were factory-installed with 34 Ah batteries. In the first one, I replaced the battery with a 63Ah one (that's what I got), i.e. almost twice the capacity, it served for almost 10 years, the generator coped with it perfectly. Of course, it was periodically charged with a charger before the winter, in accordance with the theory at that time. In the second one, the switch in the voltage regulator was broken, I replaced it with 2 silicon diodes on the heat sink and surprisingly, the charging was better than with the original regulator. I replaced the standard bulbs with halogen ones and the generator worked.
Charging a battery fully can be compared to filling a bucket - you can only pour as much water into a full bucket as you have previously taken from it and nothing more.
As for charging voltage in cars, past and present. In the past, in cars with generators or alternators, the voltage was maintained at 14.4-14.5 V, but there the voltage regulator was not interlocked with the generator or alternator as it is now and was not heated by them. In today's cars, alternators have much more power than the old ones, they are also smaller in size, so they have excessive parameters, which results in excessive heating. And if it weren't for the patent of interlocking the alternator with the regulator, these alternators would often burn out. This blocking means that with a cold engine (alternator), the charging voltage is 14.4 V, but when the alternator temperature increases, and it increases quickly and high (I measured 70°C after driving), the voltage starts to drop and stabilizes at 13.8 V (this is the case in my case and in a few other cars in which I checked it out of curiosity), and sometimes even less. This behavior of the voltage saves the alternator from blowing up, but also changes the battery charging conditions - it makes them worse, because you need to drive much longer to fully charge the battery than with a voltage of 14.4 V. This is the current reality, and learning, and it's nice, is called it's intelligent charging of the battery by the computer and people are taking it.
There are similar myths about charging batteries outside the car.