Last call for suggestion on a USB meter, 0.001 A and maybe a cable test

Ebay has a 10% ebate going through tonight, so I want to buy something while its active. In addition to the 1ma accuracy, actually just show current below 10ma even if its not great accuracy overall, I see some will test USB cables for resistance and type, which sounds good to have.

I’ll be searching on my own, but actual suggestions on units to buy that sell on ebay appreciated. Thanks.

If possible, look for the UM25/UM25C on eBay.

It’s extremely accurate, as per HKJ’s testing down to the 1/1000, rather than 1/100, and quite precise.

It can also be used with Bluetooth, which means you can log the info, and put it in an Excel file, which is very useful.

It can also handle 5A max, at up to 24V. It’s got a micro USB input, USB-C input/output as additions to the USB-A input/output. It also support USB protocol recognition. Finally, it supports USB-C PD pass through. No protocol activation/recognition though.

If you want compatibility with Dash Charge, look for the UM34/UM34C. Less accurate and less precise, but supports Dash Charge passthrough.

If you could, I would buy from the RD Tech store. They are the official manufacturer of the UM series of USB power monitors.

If you say you are from BLF, they will give you a small discount, about 5. It’s worth it IMO since I support them directly, and their customer support is great, even with a 5 higher price.

eBay link:

Aliexpress official store link:
https://www.aliexpress.com/item/RD-UM25-UM25C-for-APP-USB-2-0-Type-C-LCD-Voltmeter-ammeter-voltage-current-meter/32855845265.html?spm=2114.search0104.3.3.17f97e5bSrB3lD&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10130_10547_10059_10548_10696_100031_10084_10083_10103_451_452_10618_10139_10307,searchweb201603_54,ppcSwitch_2&algo_expid=e2869c11-4b0a-44eb-b303-be5593ce0714-0&algo_pvid=e2869c11-4b0a-44eb-b303-be5593ce0714&transAbTest=ae803_1&priceBeautifyAB=0

Both the UM25/UM34 can log in the resistance of the cable using a USB electronic load.

Thanks, UM25 sounds like a good option, skipping bluetooth for now due to issues with app software and pop up ads.

Did you get the UM25 and like it?

The Ali page for that link is quite confusing, is “Aideopen” the manufacturer?

I don’t see any way to buy from the RD Tech store and contact them for a BLF price.

But I’ve got a box full of dubious cables to test, so ….

I’m not sure that there is any special BLF pricing, but you can message them via AliExpress and ask.

Or send them a message on BLF:
http://budgetlightforum.com/user/20499

But given that it’s Chinese New Year, I wouldn’t expect a reply right away.

Also:

I think I picked the cheapest vendor on ebay, TWICE. Tracking on first showed delivery to my front porch on a day when I was home all day working next to the front porch, no idea what happened to it, but found nothing on porch or neighbors, and had never had prior issues. Second one less drama, played with it a few days, technically worked as advertised, but turn out most of my digital device draw power in some fashion closer to pulses so while the display is showing all those nice expensive to acquire digits, they change so much from sample to sample to be useless. Bluetooth was fun, worked fine with my LG phone, the old $3 USB doctor is back in use and the fancy one in its box waiting a purpose.

The details of cable testing didn’t seem all that practical vs buying some “known” good cables and stop using any questionable ones. Some cables I am sure are not very good, but I’ve had more issues with devices and chargers and its hard to decide if adding a meter to mix helps find the issue or adds a new variable.