This is a very interesting question and the answer to this question is a big “NO”. A poor-quality battery, a weak battery, or a wrong size battery can have no effect on the alternator. An alternator is a special or very important thing in a vehicle. It is a dynamo or an electric generator. A weak battery cannot have any effect on alternator, but a poor or weak alternator can deteriorate the battery very quickly. A broken battery also has an effect on an alternator as it puts more pressure and stress on the alternator while working and sometimes destroy the alternator as well.
When a broken battery put more pressure on the alternator, it doesn’t help in keeping the vehicle functional and operational. It is true that you need to use a good quality battery because it will help keep the engine in well-functioning form. When you use a weak battery or a smaller battery, it will lead to a loss of power. You will feel that the supply of power for your engine is not good and you will need to use an alternator or AC. Other than having an effect on AC, a wrong size battery and weak battery will have a very bad effect on the car’s engine. In such cases you will need to keep the battery updated so that the vehicle can work. Ultimately, you will use an AC that may not get affected by that battery as it has no connection with it. It is a separate part of the vehicle that is used during emergencies.
Sometimes it is also claimed that a large battery place in the vehicle can harm the alternator, there is truth in this matter too, because both these parts of the vehicle work differently and separately. Although the purpose of working of both these parts is same that is to run the vehicle, but the method and performance of both is different. Both are not getting affected with each other. However, if the alternator of the vehicle has been drained, it can drain the battery too and battery will decrease in a short time period along with affecting the performance of the vehicle and the engine as well. A bad alternator shuts off the battery’s circuit and you cannot recharge the battery and when the battery will not be charged, the car will not be started.