SKY RC MC-3000 Resistance Measurement Problem - Page 1
Forum section: electronics / general

author: Neshco
author_rank: Contributor
timestamp: July 25, 2025, 08:38:04 pm
content: I own this device fro quite some time and intermittently use it to check the health of some batteries, charge/discharge etc, and it work just beautiful, no complain, no problems, except resistance measurement. It often easily double the values that I measure with Zoyi ZT-DQ02 and YR1035, which both pretty much consistent and similar measurement.Springs load nice I would say, does not matter which slot I use, did not help cleaning contacts with alcohol, so it is definitely some issue with the device.Recently, I have updated it to the newest fw version 1.23, did not help at all.There is a lot people online complain on this, but no one found the solution.Is there anyone who did find a way to fix this, calibrate, or whatever?

author: thm_w
author_rank: Super Contributor
timestamp: July 25, 2025, 10:44:14 pm
content: Its normal for these cheap smart chargers to not be too accurate in terms of resistance, but current and voltage is quite accurate. OK this unit is not cheap, but it looks the same form as those you can get for $30 from aliexpress.Is the resistance consistent and just has an offset?Did you try measuring the resistance of the spring mechanism with your YR1035?

author: Neshco
author_rank: Contributor
timestamp: July 25, 2025, 11:00:34 pm
content: It's far from cheap, needed to have some charger like that, and decided to spend some money for decent one and this happens.No it is not consistent, it is all over the place some time.What do you mean by measuring with the YRs module? It is Kelvin clamp system, cannot attach it to the MC3000. I mean, I can, but I am sure it would show same results. Every single slot show more or less same results. It appears that I can forget resistance measuring on it. I mean, I have this two devices but this is more convenient to have it all in one place.

author: thm_w
author_rank: Super Contributor
timestamp: July 25, 2025, 11:41:52 pm
content: Its still going to be using the same mechanism to test the cell resistance as the cheap units, different from what YR1035 is doing. I don't even see a spec for internal resistance in the manual?You can measure the slider resistance by pressing the probes on one side where the battery contacts the slider, and the otherside on the PCB itself. But this would probably require taking apart the unit. Move the slider around and see if the resistance changes.If the problem is the slider, maybe you can solder some copper wick to improve the connection, but its going to be ugly.

author: symphonystars
author_rank: Newbie
timestamp: July 26, 2025, 01:52:12 pm
content: owning a mc-3000 i can confirm its IR test can be kinda wonky. Unlike the YR1035 it only does a 2-wire measurement and making things worse the plate that touches the negative side of the battery is not wired directly to the pcb(connects to the pcb through a sliding contact with the metal rail beneath).Mine at some point got so bad due to oxidation that i had to connect the sliders directly to the pcb with a wire, but at least since the fix the resistance values are quite consistent and close to what are supposed to be(50-55mOhm on the mc-3000 and about 30mOhm on the YR1035+)

author: Neshco
author_rank: Contributor
timestamp: July 26, 2025, 02:17:13 pm
content: Omg, I havent disasemble it yet, so it goes over slider. It explain a lot.Thank you for tips, I will for sure do that, and maybe even gold plate contact areas.