Put the Car in Park or Neutral when Idling

 When you idle, put the car in Park or Neutral.  Keeping it in Drive puts torque on the torque converter. 

Replace Alternator, 2012 Camry, Friday, April 5, 2024

The mechanic charged me $520, down from $528.  Nice of her, eh?  Okay, so the weak alternator was draining my battery, and not the case of a weak battery draining the alternator.  The alternator charges the battery.  All of your car's appliances--seat controls, heating & air conditioning, 

IGNITION, BATTERY, STARTER, 

A starter-mounted solenoid has three terminals with three connections: the battery (B), start (S), and motor (M) terminals.

Yes, idling does charge car batteries, but not as quickly as when you’re out for a drive.

https://www.lesschwab.com/article/batteries/how-your-auto-battery-works.html. 

The ignition switch: starter button you press or where you insert your key.

The switch controls the starter relay (also called a solenoid). When you turn the ignition, it sends a small electrical current to the starter relay. This causes a pair of contacts to close.

When those contacts close, the battery sends voltage to the starter motor, which turns some gears to start the car.

The two types of auto batteries — flooded and AGM batteries — use lead-acid technology. A typical lead-acid car battery contains plates of lead alternating with plates of other materials, all immersed in an electrolyte solution of about one-third sulfuric acid and two-thirds water.

Turning the ignition triggers the acid in the liquid electrolyte solution to react with the active material on the plates (active material refers to any substance in the battery that reacts with the solution to discharge or recharge the battery). This generates a bigger electrical current. The current travels through the starting system in a chain of reactions that cues the engine to start.

STARTER

Pair of contact?