I am able to duplicate this issue. The MT2070's battery is drained until the unit doesn't power on. I attach the RS232 cable with the power supply attached, the unit still doesn't power on. I leave the cable connected for 10 minutes, press the trigger to turn it on. The unit doesn't power on. I must disconnect the cable, remove the battery and do a cold boot. This is the only way that I can get the unit back on after the battery is dead. I need to know if this is by design. I would hope that the battery would turn the unit on once it received enough charge, I am not seeing that.
MT2070 powering up after dead battery indication// Expert user has replied. |
16 Replies
I tested with a 2070 with a battery that had been discharged to cause it power off. I attached the USB cable. When I came in in the mornimg the device had restarted by itself. There is a note in the PRG on page 1-11 that describes this behavior:
This sounds like an SPR to me. The unit should turn on by itself.
In my testing the unit does turn on by itself.
It took 1 hour when connected RS232.
Here is the latest. My MT2070 was connected into the USB port for about 3.5 hours. It still hadn't reset. I disconnected it, it came on and showed a battery level of 11%. I guess the unit didn't power up as the USB connection hadn't been refreshed after it reached the 5% mark. If this is how the unit will function with the USB connection, then this should be added to the note. The unit comes on without user intervention with the RS232 connection, but not with the USB connection. Should a SPR be created to modify the document? Or can it be changed without one?
Corinne, to my knowledge, this is a known scenario that has no solution in Rev A other than change the battery.
Since we know that with a dead battery and a USB cable, the charging takes more than 2 hours, should the note in the user's guide be changed to state that? There will be a difference in time with the USB cable and the RS232 cable. I think that the note should explain that.
Corinne, out of curiosity, how long does it take for the RS232 cable to boot up a dead battery?
USB port only supply 100mA, but part of the scanner consumes some of it. So the net current going to the battery is even lower. I would not let the battery charge over the USB cable in this scenario. I would just swap the battery.
What happens if my customer has only 1 MT2070 and 1 USB cable? Do I tell him to wait for what number of hours to use their unit? Can anything be done to assist with this, assuming that the end user doesn't have spare equipment to use?
I am now connecting the scanner into the USB port. It has been connected for over 2 hours and still hasn't come on. The scanner isn't seen by device manager when it is connected. How can it get power if the USB port doesn't see us?
Keep in mind that when battery is really dead and charged only by USB cable (which can not be enumerated since the scanner is not booted up yet), the charge current is very low. It could be much lower than the 100mA. How long it takes depends on how dead the battery is.
How long do you think? I just put the unit in the cradle and it is at 2%. Is the USB port providing power even though the unit isn't being seen in device manager?
The end user said that his unit powered up by itself after the cable was connected for 1 hour. I am testing my MT now as well. I will wait until it powers up and then see what the percentage of charge on the unit is.
My MT powered on after about 1 hour. The battery level is at 5%.
If the battery is really dead, it is by design (at least for Rev A) that CPU is being held in reset on bootup until the battery is charged up to threshold (say 5%). The USB or RS232 cable does charge the battery, but at pretty low current about 100mA. After a while (you saw about 1hour in your case) when battery is charged above the threshold, the CPU is out of reset and start booting.