Changing batteries is frustrating.
Let me amend that. Determining if a batter is really sufficient to power a particular device is difficult when (1) you don't know the exact power requirements of the device; and (2) the testing device you employ is insufficiently precise to measure the actual potential energy available.
I have a set of four batteries which were taken out of a device. At least one of them is degraded enough to prevent the device from turning on. Using the el-cheapo batter tester from Radio Shack, I can't tell which of the batteries is the culprit. They all read "Good".
You ask: Why is that?
I'll tell you.
Every type of electronic device is different, and each type of device has different power requirements. Some need lots of voltage, requiring multiple batteries. Some need lots of current, requiring large batteries. A flashlight might require a single AA battery, or a bank of four D batteries, depending on the type of lamp and the brightness needed.
Every battery is designed to provide a certain maximum power for a given amount of time. For example, most AA batteries are designed to provide between 150 and 200 milliamps of current for approximately 10 hours of use. That is why they are "rated" between 1500 mAh (150 milliamps x 10 hours = 1500 milliamp-hours) and 2000 mAh.
But the el-cheapo battery meter can't determine if the battery under test will need to provide 150 mA or 200 mA. So instead it has a range of "Good" values based on the average use. This meter indicates that a battery is Good if it can provide anywhere from 150 mA to 200 mA.
That's OK for most devices. But if the device requires no less than, say, 190 mA, then the battery that reads "Good" on the meter, still isn't quite "Good" enough.
Cameras and the Batteries that Support Them
My old digital camera uses two AA batteries; the new one uses four. One requires (1.5V x 2 = ) 3 Volts and the other (1.5V x 4 = ) 6 Volts. But one will take about fifty photos and the other will take over two hundred.
The old one draws current out of the battery at a prodigious rate, and when that little "low battery" warning comes on, it means business. The camera is about to die.
The new one is a current miser, and when the warning comes on, it means you have plenty of time to start thinking about getting some batteries because you probably can take another twenty or thirty pictures before the real warning comes on.
When the warning appears on the old camera, it generally means that one of the batteries is marginal and the other is severely depleted. Because that camera will keep pulling current out of the batteries even if the voltage drops quite a bit.
But when the final warning goes off on the new camera, and it refuses even to power up when the ON button is pressed, the batteries appear to have plenty of juice still in them - at least, according to the el-cheap meter.
Why is this?
I can only surmise; but it seems that the old camera doesn't really care what voltage it is getting out of the batteries, so long as it can pull enough current out. (And, as we all know, the voltage of a battery decreases gradually with use, then drops off rapidly once it reaches a critical depletion value.) Whereas the new camera has a specific cutoff voltage whereby, in order to protect it's delicate electronics from spurious logic, operation ceases if the voltage drops below that point.
Ultimately, it means that it is difficult to determine if a set of batteries will work for the new camera based solely on the reading from some cheap meter.
Good luck finding a "Good" set of batteries that will work with those kinds of devices.
The el-cheapo battery tester has three markings: Green for "Good", Yellow for "Marginal", and Red for "Dead". There are no sub-distinctions for "Kind of Good" or "OK for most things but not for your fancy-pants computerized electronics".
I have this plastic tub full of batteries which all measure "Good", but they don't work in most of the newer electronic devices. Some devices apparently need "Extra Good" or "Practically New" or else they won't work. Others - especially flashlights - seem to be just fine with "OK", "Good", or "Whatever".
Our new camera (FinePix S2980) uses four AA batteries, and thus it uses a lot of current at a relatively high voltage. Batteries which measure "Extra Good" or "Practically New" will work with it; others do not.
I was curious to know just how "Good" the battery had to be in order to work in the camera, so I took one of the batteries which had read "Good" on the el-cheap meter but failed to function in the camera, and compared it to one which worked in the camera using my handy-dandy el-cheap ($10) multimeter.
(The multimeter includes a batter-testing scale down at the bottom, but I ignored it because it is about as useful as the other one; instead, I referred to the "V-mA" scale with the black numbers.)
The good working battery tips the needle here at the 200 line on the topmost V-mA scale. Since most AA batteries are supposed to provide around 200 milliamps at full charge, I'm going to pretend that this is the reading that should occur for a Good battery.
The bad battery tips the needle here at between 190 and 195. That's not much of a difference between the two. So apparently the battery, once it steps just a toe over the line, is no good, and must be replaced.
Leaving me with a huge tub of not-quite-good-enough batteries. Which are probably only useful for simple electronics like flashlights.
Obviously, I can't throw them out. But what am I to do with them?
Where did all this come from? you ask. And rightly so.
It came about because I was trying to get a picture of Mary playing guitar one morning using the new camera, and the camera died right after I'd taken the picture.
Well, that's not a catastrophe. It took the picture - at least, I thought it did. So all I had to do, was to pull the flash card out and copy it over to my laptop, right?
Wrong.
The camera had enough power to create a file on the flash drive on which to store the data from the picture, but it died before it could actually write the data to the file.
Which meant that the flash drive contained file with nothing in it.
This is one of the errors that that fancy power-detection circuitry in the camera is supposed to prevent. It is supposed to determine if there is enough power in the camera to store pictures on the flash drive, and, if there isn't, it is supposed to shut down the camera.
Mine apparently isn't calibrated quite right. Because it allowed me to power up the camera and take pictures of Mary - twice! - but then failed to actually write the data to the flash.
(Yes, I tried to take a picture of her the next morning after changing batteries, but apparently the new batteries were no better than my old ones.)
So I spent half an hour going through my tub of batteries, looking for "Good" ones and testing them in the camera, and discovered that only the ones which read high on the multimeter actually worked in the camera.
And I discovered that the vast majority of the batteries in the tub are good enough for other things, but not good enough for the camera.
And I don't throw anything away if it can still be used for something.
So now I have a tub of almost-good batteries and need to find something they can be used in.
And I still don't have a good picture of Mary playing guitar yet.
Let me amend that. Determining if a batter is really sufficient to power a particular device is difficult when (1) you don't know the exact power requirements of the device; and (2) the testing device you employ is insufficiently precise to measure the actual potential energy available.
 |
| This is Good |
 |
| This is Bad but reads "Good" |
You ask: Why is that?
I'll tell you.
Every type of electronic device is different, and each type of device has different power requirements. Some need lots of voltage, requiring multiple batteries. Some need lots of current, requiring large batteries. A flashlight might require a single AA battery, or a bank of four D batteries, depending on the type of lamp and the brightness needed.
Every battery is designed to provide a certain maximum power for a given amount of time. For example, most AA batteries are designed to provide between 150 and 200 milliamps of current for approximately 10 hours of use. That is why they are "rated" between 1500 mAh (150 milliamps x 10 hours = 1500 milliamp-hours) and 2000 mAh.
But the el-cheapo battery meter can't determine if the battery under test will need to provide 150 mA or 200 mA. So instead it has a range of "Good" values based on the average use. This meter indicates that a battery is Good if it can provide anywhere from 150 mA to 200 mA.
That's OK for most devices. But if the device requires no less than, say, 190 mA, then the battery that reads "Good" on the meter, still isn't quite "Good" enough.
Cameras and the Batteries that Support Them
My old digital camera uses two AA batteries; the new one uses four. One requires (1.5V x 2 = ) 3 Volts and the other (1.5V x 4 = ) 6 Volts. But one will take about fifty photos and the other will take over two hundred.
The old one draws current out of the battery at a prodigious rate, and when that little "low battery" warning comes on, it means business. The camera is about to die.
The new one is a current miser, and when the warning comes on, it means you have plenty of time to start thinking about getting some batteries because you probably can take another twenty or thirty pictures before the real warning comes on.
When the warning appears on the old camera, it generally means that one of the batteries is marginal and the other is severely depleted. Because that camera will keep pulling current out of the batteries even if the voltage drops quite a bit.
But when the final warning goes off on the new camera, and it refuses even to power up when the ON button is pressed, the batteries appear to have plenty of juice still in them - at least, according to the el-cheap meter.
Why is this?
I can only surmise; but it seems that the old camera doesn't really care what voltage it is getting out of the batteries, so long as it can pull enough current out. (And, as we all know, the voltage of a battery decreases gradually with use, then drops off rapidly once it reaches a critical depletion value.) Whereas the new camera has a specific cutoff voltage whereby, in order to protect it's delicate electronics from spurious logic, operation ceases if the voltage drops below that point.
Ultimately, it means that it is difficult to determine if a set of batteries will work for the new camera based solely on the reading from some cheap meter.
Good luck finding a "Good" set of batteries that will work with those kinds of devices.
The el-cheapo battery tester has three markings: Green for "Good", Yellow for "Marginal", and Red for "Dead". There are no sub-distinctions for "Kind of Good" or "OK for most things but not for your fancy-pants computerized electronics".
I have this plastic tub full of batteries which all measure "Good", but they don't work in most of the newer electronic devices. Some devices apparently need "Extra Good" or "Practically New" or else they won't work. Others - especially flashlights - seem to be just fine with "OK", "Good", or "Whatever".
Our new camera (FinePix S2980) uses four AA batteries, and thus it uses a lot of current at a relatively high voltage. Batteries which measure "Extra Good" or "Practically New" will work with it; others do not.
I was curious to know just how "Good" the battery had to be in order to work in the camera, so I took one of the batteries which had read "Good" on the el-cheap meter but failed to function in the camera, and compared it to one which worked in the camera using my handy-dandy el-cheap ($10) multimeter.
 |
| Reading from a Working Battery |
(The multimeter includes a batter-testing scale down at the bottom, but I ignored it because it is about as useful as the other one; instead, I referred to the "V-mA" scale with the black numbers.)
 |
| Reading from a Bad Battery |
The bad battery tips the needle here at between 190 and 195. That's not much of a difference between the two. So apparently the battery, once it steps just a toe over the line, is no good, and must be replaced.
Leaving me with a huge tub of not-quite-good-enough batteries. Which are probably only useful for simple electronics like flashlights.
Obviously, I can't throw them out. But what am I to do with them?
Where did all this come from? you ask. And rightly so.
It came about because I was trying to get a picture of Mary playing guitar one morning using the new camera, and the camera died right after I'd taken the picture.
Well, that's not a catastrophe. It took the picture - at least, I thought it did. So all I had to do, was to pull the flash card out and copy it over to my laptop, right?
Wrong.
The camera had enough power to create a file on the flash drive on which to store the data from the picture, but it died before it could actually write the data to the file.
Which meant that the flash drive contained file with nothing in it.
This is one of the errors that that fancy power-detection circuitry in the camera is supposed to prevent. It is supposed to determine if there is enough power in the camera to store pictures on the flash drive, and, if there isn't, it is supposed to shut down the camera.
Mine apparently isn't calibrated quite right. Because it allowed me to power up the camera and take pictures of Mary - twice! - but then failed to actually write the data to the flash.
(Yes, I tried to take a picture of her the next morning after changing batteries, but apparently the new batteries were no better than my old ones.)
So I spent half an hour going through my tub of batteries, looking for "Good" ones and testing them in the camera, and discovered that only the ones which read high on the multimeter actually worked in the camera.
And I discovered that the vast majority of the batteries in the tub are good enough for other things, but not good enough for the camera.
And I don't throw anything away if it can still be used for something.
So now I have a tub of almost-good batteries and need to find something they can be used in.
And I still don't have a good picture of Mary playing guitar yet.
1 comment:
87just try again
Post a Comment