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JakeRich · 04-03-03, 08:48 PM

Power Consumption
Sleep: 0.6mA
Read: 65mA max.
Write: 36 - 125 mA max.

Those were the specs on the memory CF card that ceej13 pointed to and

System Power Requirements @3.3V
Read: <33 mA
Write: <35 mA
Standby: 300 µA

those are the specs on the SD card. Now for the math.

The axim draws about 200 ma of power when running. You get to that number from the typical 7 hours running on a 1440 mah battery. So if you put in a CF card but didn't access it at all, the net change would be from 200 ma to 200.6 ma of current, and when you read it would be 265 ma and writes would range between 235 and 325 ma draw. For the SD card the numbers would be 200.3, 233 and 235, respectively. Now the big numbers are only for when the actual read and write is happening, like opening an app, opening a file, saving a file, etc. That activity is very quick and unless you are transferring a mega file, it takes a few seconds. With the card just installed and not being accessed, the additional draw is less than 1%.

So, the answer to the question is, "Yes, they draw some power, but not very much and not really enough to affect battery life unless you read and write continuously." For most of us the practical answer is "not really."

Now you could have a problem card that somehow is shorted out and drawing a lot more power than specs call for, but it would probably be very warm to the touch if that were the case. You might let it run for a while and then shut down, remove the card and feel for the heat. If it's hot, I'd get a replacement.

04-03-03, 08:48 PM	#9 (permalink)
JakeRich Aximsite Hall of Fame Join Date: Nov 2003 Posts: 7,876 Thanked 1 Time in 1 Post	Power Consumption Sleep: 0.6mA Read: 65mA max. Write: 36 - 125 mA max. Those were the specs on the memory CF card that ceej13 pointed to and System Power Requirements @3.3V Read: <33 mA Write: <35 mA Standby: 300 µA those are the specs on the SD card. Now for the math. The axim draws about 200 ma of power when running. You get to that number from the typical 7 hours running on a 1440 mah battery. So if you put in a CF card but didn't access it at all, the net change would be from 200 ma to 200.6 ma of current, and when you read it would be 265 ma and writes would range between 235 and 325 ma draw. For the SD card the numbers would be 200.3, 233 and 235, respectively. Now the big numbers are only for when the actual read and write is happening, like opening an app, opening a file, saving a file, etc. That activity is very quick and unless you are transferring a mega file, it takes a few seconds. With the card just installed and not being accessed, the additional draw is less than 1%. So, the answer to the question is, "Yes, they draw some power, but not very much and not really enough to affect battery life unless you read and write continuously." For most of us the practical answer is "not really." Now you could have a problem card that somehow is shorted out and drawing a lot more power than specs call for, but it would probably be very warm to the touch if that were the case. You might let it run for a while and then shut down, remove the card and feel for the heat. If it's hot, I'd get a replacement.