eli5, why do batteries from the factory last so long?

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Watches, key fobs, car batteries all seem to last at least 5 to 10 yrs, sometimes longer. But once they are replaced, you need to do so yearly?

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Anonymous 0 Comments

12-volt car batteries are a type of rechargeable battery, and the car has a charger to keep it charged. In a gas/diesel car, an alternator that uses power from the engine to drive a generator; in an electric car, a separate charger.

The typical 12-volt car battery is a lead acid battery. They’re really heavy, and can be dangerous when damaged, but they are nice in that they really last a long time of you just use them a bit and then charge them up to top them off. They can also provide quite a bit of power, even when cold.

Electric cars have a 12-volt lead acid battery AND a high voltage (400V or 800V) battery pack filled with many smaller rechargeable lithium batteries. The high-voltage battery powers the motors, and the low-voltage battery powers the car’s other electronics and connects / disconnects the high-voltage battery. The high voltage battery can charge the low-voltage one when it’s connected. The low-voltage battery in EVs tends to do a lot of work when the high-voltage one is not connected, which means it tends to go to lower charge before charging up again, which makes them wear out a bit faster.

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