Even then, I regret not having bought one when I could 
That’s shocking high and definitely not what I was expecting (I was expecting about 10% which was what I was used to see with my late LaCrosse BC700 albeit in NiMH-land) .
Maybe your results were with the previous model of the MC3000 with the not-quite-inoxidable contacts? I’ve researched and the latest MC3000 uses much better materials for the battery contacts and possibly wouldn’t be that bad…
Problem is: you can’t know if it’s correct or not. Four wire measurement eliminates the uncertainty of contact resistance.
Looks like there’s a larger population of mad scientists and big corps here in BLF than I thought 
We’re in actual agreement on that. What we (still?) disagree on is whether all 4 contacts must necessarily (for ~10% precision) touch the battery directly as in the iron-maiden-like apparatus
@HKJ uses, or if the single-external-good-large-contact-with-separate-probes-internally is Good Enough™ for that. I hope to determine that to my own satisfaction for my incoming SkyRC MC3000 in the next few days provided the Andean delivery gods smile on me 
I was actually somewhat disturbed when I saw that pic, but couldn’t at the time quite put my finger on the reason – now I think I figured it out: that thing looks just like an iron maiden torture apparatus but for batteries! 
I think the only thing missing is a special microphone to record the supersonic screams the battery must make when being tested in there so @HKJ could graph their decibels vs charging current etc
I swear I haven’t had a drink in like >3 years. But I fall asleep mid-comment while still holding my phone all the damn time lmao
If you ever see a comment like that from me it’s because I literally fell asleep halfway through writing it lol
Ill try and fix it when I wake up usually
That sounds like a great idea! Surely not as good as @HKJ’s battery torture apparatus , but perhaps more than good enough for customer level equipment.
I haven’t tried this myself but it makes sense, this guy here suggests if you open the charger up and bypass the sliders and springs you can get more consistent resistance measurements.
I’ve also found wiping the contacts down with a little iso and a cloth makes a big difference. Not just dabbing it with a little qtip you gotta actually get a cloth and wipe them down.
You can still buy those things on AliExpress and places. Not exactly the same as that but pretty darn similar. I like the aluminum ones, they look a lot better
yep, but given the date of his post (2018) I’m pretty sure he had an old unit with less-than-ideal material in the contacts.
This IMO corroborates the idea that it could be corrosion (perhaps very light, invisible corrision) on the contacts that’s causing the imprecion, and not the 2-pairs-of-probes-direct-to-battery thing.
EDIT: just heard I should receive my SkyRC MC3000 tomorrow. Fingers crossed!
EDIT2: just read the post you linked and the guy had an Opus, not a SkyRC… 
All these chargers use the exact same setup with the sliders and the springs, it applies to any and all of them.
I agree that they externally all look the same. But besides the matter of the contact material (which in the MC3000 I know for a fact that SkyRC replaced it recently to avoid issues with corrosion), there’s also the mattter of how they’re connected to internally: they could have just a single wire to each contact and try to measure both voltage and current with it (which as we have seen would not be ideal) or have two wires connecting to two different points at each contact, which would not be as great as @HKJ’s ‘iron-maiden battery torture apparatus’ but would be a step in the right direction.
Alas didn’t manage to get my SkyRC MC3000 yesterday as it was a holiday here. I expect to get it today or worst-case tomorrow, and then I will be able to offer more than mere speculation.
No I’m talking about internally, but just about the sliding battery holder. Idk how they do the measurements afterwards, that varies I’m sure, but they all do the actual physical build of sliding battery holder the same way. The positive post is soldered to the board, the metal strip with the sliding negative post is soldered to the board, but not at the point where there would be the lowest resistance. Bypassing it with a wire would work on any of them, no matter how they measure resistance and current, bypassing the varying resistance of the slider and spring is anyways gonna give you more consistent measurements I think.