Shop with DX Mobile Site Yes No

Jtron 0.91" 128*32 OLED USB Voltmeter Current Power Capacity Tester

Jtron 0.91" 128 x 32 Dot Matrix 3-Bit OLED USB Voltmeter Current Power Capacity Tester

by Jtron
4.2 ( 6 reviews)
SKU: 382577
  • US$12.99

    20 %

  • 10.40
  • Free shipping To

  • Handling Time: Ships within 1 Business Days
  • Dispatch: Ships within 4-7 business days
  • Form Color:

    Translucent Blue Blue

Jtron 0.91" 128*32 OLED USB Voltmeter Current Power Capacity Tester
Jtron 0.91" 128 x 32 Dot Matrix 3-Bit OLED USB Voltmeter Current Power Capacity Tester

Jtron 0.91" 128*32 OLED USB Voltmeter Current Power Capacity Tester

US$10.40 US$12.99 20%OFF 4.2 (6 reviews)
Add To Cart

It forbid for being used for inductive load, eg: the load with motor and fan. it can be used digital products, eg: mobile phone, power bank, USB flash drive and etc.


Overvoltage, undervoltage remind

Screen flip up / down storage

USB signal lines through without affecting communication

The screen turns off

Group 9-capacity storage

Unit switching capacity

Automatic calibration current zero

Display color: white

When contact the power supply, the screen shows welcome window firstly and then comes into main interface. The first line displays voltage, power and data set. The second line displays current and accumulated capacity.

Current zero calibration function  

Because of the influence of component aging and temperature variation after long-term use, the error may become bigger when it measures small current. So you can keep pressing the button on the back to connect power supply in the no-load terms, until the LED lights. The calibration is accomplished.

Over-voltage and Under-voltage reminding function:

When the voltage is over 5.3V (less than 4.7V), the arrow ˆ (ˇ) will be flashing to remind the voltage is too high (low). When the voltage becomes to 4.7V-5.3V, the arrow will be disappeared.

In the main interface, you can click the button to switch data set one by one. And it provides for storing and checking 0 to 9 totally ten group data set.

Capacity stored function

When data set is between the 1 to 9 group, the current capacity will be stored after power off. And the stored capacity will be accumulated after power on. When the data set is 0 group, the current capacity will be stored after power off. When power on next time, the stored MAH is blinking displayed .When the new MAH is up to 1 MAH, the stored MAH will be covered, and the values will start over.

 In the main interface, click 2 times the button on the back (the time interval of the two times is within 0.5s), then you can get into data check window and see the capacity of the current data set. In this window, you can click the button to check the next data set, and when you keep pressing the button more than 2s, the current data set will be cleared. And if you click the button two times, it will come back to the main interface.

Counting the capacity and efficiency of the mobile power bank battery:

Ah data * output voltage ÷battery voltage ÷ efficiency = mobile power bank battery Ah (output voltage is typically 5V, the battery voltage is generally based on 3.7V, typically by 85-90% efficiency)

Capacity unit switch function:

In the main interface, keep pressing the button, until the LED lights (time about 2s), loose the button, the capacity between mAh and mWh is switched.

Screen rotation function:

In the main interface, keep pressing the button, until the LED lights and then goes out (time about 4s), loose the button, the screen is rotated and automatically stored for being used next time conveniently.

Shut-down screen function:

In the main interface, keep pressing the button more than 6s, then loose the button, the screen display can be shut-down and come into power saving mode. In the meaning time, the LED is flashing. You can click the button to come back to the main interface.


Quantity1 piece
Form ColorTranslucent Blue
Screen Size0.91 inch
Powered ByUSB
Battery included or notNo
Other Features
Other FeaturesProduct model: USB meter (L); Voltage range: DC 3.700-7.000V; Voltage accuracy: ± (0.3% + 2words); Current range: DC0.000-3.000A; Current accuracy: ± (0.8% + 3words); Capacity accumulation: 0-99999mAh; 0-700Wh; Capacity resolution: 1mWh; 1mAh; Idle discharge: about 10mA; Display screen: 0.91 OLED screen; Update rate: 2 times/s.
Dimensions & Weight
Dimensions 2.24 in x 0.79 in x 0.39 in (5.7 cm x 2 cm x 1 cm)
Weight 0.46 oz (13 g)
Packing List
1 x USB Tester

All packages from are sent without DX logo or any information indicating Due to package variations from suppliers, the product packaging customers receive may be different from the images displayed.

To enable volume discounts on this site, use coupon code: BULKRATE during checkout. You will see a discount applied at the bottom of the shopping cart. Competitive pricing is available. Contact us for details.

Quantity 3+ units 5+ units 10+ units
Rate US$9.22 shipped US$9.19 shipped US$9.16 shipped

What is Bulk Rate? BulkRate is a semi-wholesale system with items priced separately from retail. When you use bulk rates, a flat $1.70 registered air mail fee will automatically be added to your cart to ensure delivery of package. While BulkRate's intention is to offer cheaper prices when you buy in bulk, because it is priced separately it on occassions show a higher than retail price. That's why we ask you to enter BULKRATE as a coupon code to manually activate the rates. You can always opt not to use the bulk rates. If you are looking for wholesale prices please feel free to contact us.

Looking to get even more?
Try VolumeRate - Gadgets Wholesale

Customer's impression:
good Useful Присылают более простую и дешёвую модель Товар совершенно не соответствует описанию Better than DX says EXCELENTE MEDIDOR USB
Create Review

Share your reviews, photos and videos here!

Review Program

Recent Customer Reviews

  • Sashock33 Post on 8/2/2016

    В 2015 году заказал этот прибор - пришёл точно такой, как в описании на сайте. В 2016 году прислали совсем другую модель, младшую в линейке - USB Meter (L), вместо старшей (H). Младшая модель 3-разрядная (3 Bit), т. е. 2 и... Read more

    Impression:Товар совершенно не соответствует описанию, Присылают более простую и дешёвую модель

    0 0
  • John767 Post on 3/28/2016

    Great product to see if a phone is really charging, and to test chargers. For this price it's really worth the cost. Comes i a nice box for storage.

    Impression:good, Useful

    0 0
  • jante1989 Post on 12/17/2015

    Pros: Wokrs fine, has own memory Cons: none Works just as required. Helps to estimate phone/tablet battery capacity and to find out a real DC adapter rating.


    0 0
  • Doublehp Post on 12/15/2015

    Item received is not item described here. I don't know if they wrote a bad description, or sent me wrong item. Item is labelled with correct SKU. It was shipped in a nice clear transparent box, with soft stuff and user Bad... Read more

    Impression:Better than DX says

    0 1
  • Laurentiuu Post on 11/17/2015

    Good product


    0 0

Most Helpful Reviews


Post a new topic

Please note that DealExtreme Forums are not a sales or product support board. For support questions, please contact us via support ticket at for a guaranteed response. We make every effort to make the quickest replies.

Tags of this product

Add your tags:

Your last viewed items

Recommendations Based On Your Recent History


DX Everywhere