2D82Auto not working on battery only power

+1-US8602350826 · Post time 2022-5-18 18:39:20

Just updated firmware to fix random pulse on O'scope. O'scope works ok now but unit needs to have USB power to operate. Tested batteries and one was low 3.52V and other was 4.22V. Charged and balanced so both were 4.0V but scope still does not work with battery alone. After sitting off for 2 days tested again. Both discharged: 2.9V and 3.5V. Plug in USB and both charge ok above 3.7 but 2D82 will not power ON without USB power plugged it? Please. I like Hantek hand held but need to work without power cord.

ying · Post time 2022-5-22 00:57:17

Before updating the firmware, did the device can charge for the battery?
If it is convenient, please share a video to study. Thanks.

+1-US8602350826 · Post time 2022-5-26 16:55:32

Yes, can charge before and now. Problem is device can only power on with USB. When USB is removed device turns Off even if batteries are fully charged. When device is off and USB removed, battery discharge quickly in 1 day. Device feels warm. Short circuit causing batteries to drain when off and no USB. Bad circuit. But no sign of burned circuit. Please send schematic for battery input power and charging. Also device will no longer enter firmware update mode. No green light flashing.

+1-US8602350826 · Post time 2022-5-26 17:16:39

Batteries do not balance. Looking at rear, battery on left only charges to 3.56V. Right side charges to 4.20V. Problem stays on left side after swapping batteries. Batteries good, no discharge when removed from device. With batteries removed, left slot always measures about 0.10V higher than battery slot on right.

+1-US8602350826 · Post time 2022-5-27 18:47:07

With batteries removed and power from USB, O'scope displayed a pulsing signal when no signal is connected. Appears to be noise from battery charging circuit. Noise also causes distortion when measuring sinewave from signal generator. Pulsing stops when one battery is installed on one side but not when moved to the others side.

Jing · Post time 2022-6-30 16:56:19

+1-US8602350826 replied at 2022-5-27 18:47
With batteries removed and power from USB, O'scope displayed a pulsing signal when no signal is conn ...

Dear Sir，
Please send me your questions via video. The email address is support@hantek.com.