Battery storage measurement

Some ICs are able to detect battery low, by measuring the voltage drop of battery. However, I'd like to know if there is any component can be used to measure remaining storage of battery?

Do you mean how many VA maintain in the batteries? Don't understand your question. Normally, they measure the voltage of the batteries only. However, to measure the voltage of batteries which are used in UPS, we have to cut down the recharging current to have right measuring. With some UPS made in the US, they use a uC with ADC to do it. Some others made in Taiwan, they use digital IC, but I found the uC is the better solution.

Battery Low detector

Follow the thread ... https://www.electro-tech-online.com/threads/radar-detector.3205/

which has a link back to an earlier thread that shows a simple indicator circuit.

If you are asking "how much power is still in the battery when the LOW indicator operates"
then ...
you need to know the battery Ah rating (amp-hours gives a ROUGH idea of the power in a new battery) - if you can find the info -- not easy!
you need to know the discharge profile of the battery and its age :?
an old zinc-carbon battery could be almost flat even though it hasn't been used; it will definately give a very different performance to a nicad or lead-acid battery.

There are a lot of variables you would need to know/measure/guess.
I don't even trust brand new (unused) battery ratings :!: as long as it can power my test gear I only worry about its age - most 12 month old batteries go in the bin regardless of charge - I hate the mess they make when they leak :wink:

Re: Battery Low detector

mechie said:

....you need to know the battery Ah rating (amp-hours gives a ROUGH idea of the power in a new battery) - if you can find the info -- not easy!
....

I suppose it is not that tough to get Ah rating.
just key in "battery" and "Ah" in google, u should get quite some links

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Re: Battery Low detector

StupidDum said:

mechie said:

....you need to know the battery Ah rating (amp-hours gives a ROUGH idea of the power in a new battery) - if you can find the info -- not easy!
....

I suppose it is not that tough to get Ah rating.
just key in "battery" and "Ah" in google, u should get quite some links

Click to expand...

Ah but, and there's always a 'but', isn't it? :wink:
Amp hours are given for a steady discharge current over time (often C20, the max current available over a 20 hour period).
If the discharge current is not steady or close to the given figure then you are back to the guessing stage, as, for example, half the current does NOT double the time - its actually longer still.
There are sophisticated battery management devices available, they calculate how much charge was put into the battery (talking about rechargeable batteries here) and then keep track how much charge was withdrawn. All the time applying some efficiency factor for the specific battery type as charge in does not equal charge out.
Klaus

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