Jiggy-Ninja said:Pretty much every single electronic device in the world with an internal, rechargeable battery (MP3 player, phones, handheld games, etc) has some way of measuring how much energy is left in the battery.
How do you measure the remaining energy in real time like that? How accurate are those methods?
Not schoolwork related, just one of those "I wonder how that works?" situations. So I didn't have any specific batteries in mind, just wondering about some ways that it's done in general.berkeman said:There are two main methods that I'm aware of. What is the context of your question? Is your question related to schoolwork? If it is, you need to tell us your thoughts on the subject before we can guide you to the answers. Even if it is not directly schoolwork, you should be able to post the results of your research so far.
Hints -- (1) pull up some datasheets on the batteries you are asking about. (2) How could a charging circuit measure and remember energy transfers...?
Jiggy-Ninja said:Not schoolwork related, just one of those "I wonder how that works?" situations. So I didn't have any specific batteries in mind, just wondering about some ways that it's done in general.
I did some googling, but the results I got were stuff like timing how long the battery takes to drain to figure out the full charge, which obviously doesn't happen for the indicators I'm thinking of. I don't quite know the right magic words to search for to pull out the answer.
My first thought was that there might be some V-Ah (Volt -- Ampere-hours) characteristic curve for to battery, ie the voltage changes in a slight, predictable way depending on the remaining charge in the battery. But then I remembered that the voltage would also vary with the load so that's no good.
I know that when the battery gets drained too far the voltage can drop pretty significantly, but that's not precise enough for something to measure, for example, that the battery is 75% charged.
The accuracy of the battery indicator on your device can vary depending on the device itself and the software it uses. In general, battery indicators are not always 100% accurate and can be affected by factors such as usage patterns, temperature, and age of the battery. It is always best to use the battery indicator as a general guide rather than relying on it completely.
The battery indicator measures remaining energy by monitoring the voltage and current levels of the battery. These levels are then compared to a pre-determined scale to estimate the amount of energy remaining. This estimation is based on the assumption that the battery's voltage and current levels decrease at a consistent rate as it discharges.
Some devices may have a calibration feature for their battery indicator, but it is not recommended to manually calibrate the battery indicator on your own. This is because the software and algorithms used to calculate remaining energy may not be accessible to users and calibrating the battery yourself may actually decrease the accuracy of the indicator. It is best to leave the calibration to the device's manufacturer or a professional technician.
The battery indicator is programmed to recognize the characteristics and behavior of different types of batteries, such as lithium-ion, nickel-metal hydride, and lead-acid. Each type of battery has different voltage and current levels, and the indicator uses this information to estimate the remaining energy. However, it is important to note that the accuracy of the indicator may vary between different types of batteries.
While the battery indicator is the most convenient and commonly used method for measuring remaining energy, there are more accurate ways to measure this. One way is to use a battery tester, which directly measures the voltage and current levels of the battery. Another way is to use a multimeter, which can measure the state of charge of the battery. However, these methods require additional equipment and may not be as easily accessible as the battery indicator on your device.