Hi, I shound measure charge battery with a microcontroller, but i have no idea how can i do it...any link,book, data-sheet, suggestion? Thanks
- posted
14 years ago
Question about charge battey measurement
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- posted
14 years ago
What kind of battery?
Sylvia.
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14 years ago
What type of battery and how accurate does it need to be?
An easy but not very good way would be to measure the voltage at the battery terminal. The datasheet for the battery will probably have graphs of charge state against battery voltage so you can get some idea of the battery state. However this method gives very poor results.
A more accurate method is to measure the current that flows into and out of the battery and integrate over time. Then if you know the battery capacity you can work out how much charge is left. However to do this accurately you need to adjust for battery age and operating temperature. Depending on the required accuracy and the battery type, you also need to take account of the battery self discharge rate.
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14 years ago
Read the datasheet that comes with the battery. As a general rule of thumb: the faster you want to charge, the more difficult it will be. The problem is that you can't really measure the amount of energy left in a battery. The voltage across a battery will vary because of the charge, temperature, current and probably the direction of the wind.
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- posted
14 years ago
You can to a reasonable degree of accuracy if you use one of the many "fuel gauge" battery charge logging chips available.
Dave.
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14 years ago
Yes. Measuring state of charge, and battery charging, varies hugely with the type of battery. It's complicated, and tied to battery chemistry. Unloaded voltage isn't very helpful. What are you trying to do? John Nagle