SkyRC MC3000 help thread

Anyone think it's a good idea to start a question and answer thread about the SkyRC MC3000 charger, how to program it and any questions related to it? I got a couple of my own questions too.

Go ahead and ask. If someone can help I’m sure they will. I recently bought my third one. Unless I’m traveling it’s the only charger I ever use now.


Three of them, not bad! I can see how this charger can be addictive. My first question.

When using Storage Mode. Does that mean it charges or discharges the batteries to 3.8V and then the slots light up green?

This is what I did under the settings menu for storage, but not 100% sure I did it right. I set this for a protected NCR18650B for starters

Batt Type: Lilon

Mode: Storage

Capacity: 3400mAh (I'm assuming it's asking for the rated capacity of the battery in the slot?)

C-Current: 0.5A

D-Current: 0.5A

That’s fine, if you want to speed things up a bit you can use a higher current. A good 3400mAh 18650 can handle 1.5A charge no problem. Storage mode will charge or discharge whatever it takes to get to the voltage you have “target volt” set to. The default is 3.8V for LiIon. Storage mode works a little different than other discharge routines in that “cut volt” and “d reduce” are ignored. Storage mode will always use “target volt” and “termination” do determine when to stop even if it’s discharging.


Thanks Frank, very helpful. Right now I am using Simple Mode, so knowing storage default is 3.8V, I'm good to go. Have not moved up to the advance modes yet where they have all the extra info in the menu. D-reduce, does that mean charging current will constantly reduce power as it gets closer to the batteries cut volt? Shouldn't make any difference if I am putting the batteries away for awhile hopefully.


I noticed that after the batteries reach storage voltage of 3.8V and no more discharge is applied, instead of the button light turning green, it still stays red. The screen will show discharge current rate at 0.00 instead to let the user know the process has completed so thought I should mention that to anyone following this thread.

D. reduce is used for discharge routines and yes it’s the current cut off after the cut volt is reached. It’s very similar to what termination does on charge routines. One of the things that I really like about the MC3000 is it will only start to lower current when target volt is reached and not before. Same with discharge it goes full current until it hits cut volt.


Got it thanks. My batteries were around 3.9v so I entered the storage info in the charger just to see what it will do to them and now they are both at 3.8v and discharge current is progressively dropping from 0.5A to now 0.11A.

I also have a lot of questions on the MC3000, knowing that many of them are theoretically explained in the very good manual. Still, theory is often different from user‘s expertise and so I‘m quite curious about:

a) How you guys measure your battery‘s capacity and internal resistance, especially with brand new cells. My question also refers to the variety of cycle modes. e.g. D-C-D or C-D-C. After an eternal journey of 65 days (probably transported by camels and horses along the silk road :wink: ) I recently received my Imalent 18650 cells from Gearbest. Those cells had a residual idle voltage of 3.28V when they arrived.

My plan is to discharge them down to 2.5V first and then charge ’em up to 4.20V and then discharge again to 3.8V for storage. Afterwards I want to know the cells capacities and their iR, so I can put a label onto the shrink sleeve. Would this plan make sense or do you have better recommendations?

b) Do you prefer the remote app via bluetooth or the UI that needs to be programmed on the device by a lot of button presses?

Thanks a lot for your feedback!

When I want to test battery capacity I use cycle mode C>D. Then depending on the results I’ll charge it, store it with a storage program or throw it away. You can do C>D>C also, the only down side is once the second charge routine starts it begins measuring charge mAh so you need to catch it between the discharge and the second charge. That amount of time is determined by what you have D. rest set to. The discharge mAh results are redisplayed only after the second charge cycle is done. IR is displayed by clicking up and down at the same time with the slots in ready mode.


I'm new to this too, but the cheat sheet on the bottom of the first page says how to test IR if that helps any.

D-Reduce will lower the charge current when battery voltage (during discharge test) gets close to V cutoff. Per the manual, this can be used to test capacity of alkaline batteries, and factors in an alkaline's ability to recover. Through experimenting, I found that setting D-Reduce to about 50% (of set discharge current) can get you close to an alkaline's rated spec. For example, a while back I did a discharge test on an Energizer C-cell. Discharge current was set to 100ma (duplicating Energizer's testing spec), and D-Reduce to 50%. From Energizer's rated capacity HERE, I got pretty close (6416mah), but not without using D-Reduce.

An interesting quote from the manual about setting D-Reduce to 0%

What is the “termination” set to? If it’s zero or –zero move it up a little to .01V or 02V. Unless the battery is in very good condition it may never settle in at exactly 3.8V. I have two storage programs saved one at 3500 cap with .05V term and the other at 900 cap with .02V term and I get the green light.


Set termination voltage to 0.01V and it worked, all green lights finally came on but had to rotate two batteries before the green light lit up so maybe I need to set termination to 0.02V and see if that works better, thanks for the help! I think it's much better to go right to the advanced menu and sort it all out from the beginning.

Thank you Frank! Just out of curiousity, is there any difference between the capacity values of a discharge process and a charge process? Let’s just say I put those brand new cells I received with 3.28V into the MC3000. Will I already get the capacity and iR values if I chose to use cycle mode C>D or do I have to run a full C>D>C cycle? At what cut off voltage do you set your MC3000 when discharging cells? According to their data sheets most cells can be discharged to 2.50V or 2.75V, the VTC6 even down to 2.00V. Some people discharge their cells to 3.00V only, so I’m wondering what you guys deem to be reasonable.

Discharge capacity is universally regarded as a more accurate test then charge capacity mainly because of the heat loss during a charge, heat is energy. Yes you will see discharge capacity after a cycle C>D, scroll through SOV and you will see IR and more. Following manufactures data sheets IMHO is a very good safe practice.


Nice infos above, about the storage modes suggestions.

Just sharing what I usually do for capacity testing — (I only use the Advance mode of the MC3000, since that’s where we could get all options) I use the default Refresh cycle of C>D>C.

But usually, I charge the battery first to 4.20v independently (maybe using a lower ending current than the normal “Charge” ending current of 1/10th selected Charge current), that way the battery is closer to really full (or so I think) — lower resistance cells will be quite quick, but high-resistance cells may take a longer time.

So, let’s say I charge an 18650 to 4.20v, but I manually select ending current of 0.03A (normally when one selects 1A charge current, ending current is 1/10th or 0.10A; select 2A charge current, the ending current is 0.20A, which is quite high and may not fully fill up the the battery). Manually selecting the ending current seems to ensure the battery stays at 4.20v even when removing the battery from the charger. (I think doing this is a bit more “stressful” to the battery though. But I do this (lower ending current) only when I want to do capacity testing).

But during the C>D>C Refresh, I usually don’t try to change the ending current anymore (so it stays at the default 1/10th). Usually I test 18650s at 0.50A discharge current (this may be lower than 0.2C for higher-capacity cells, but at least I’m testing the cells in a more “standard across different cells” or comparable way for the various 18650s; rather than testing strictly according to the manufacturer specs).

Thanks for the tip Now that I have Storage mode working perfectly, I'm going to try my first Charge mode in the Advanced menu and see if I can figure it all out. I kind of like charging my batteries to 4.1V instead of 4.2V so it's going to be nice to finally be able to do so for my batteries in series to the voltage I actually want.

Good info too thanks. I use to charge all my batteries to 4.2V, but as of late, feel more comfortable at 4.1V.

Anyone know why the MC3000 needs the battery capacity entered? I was just thinking that if I entered for example 5200mAh for my 26650 keeppowers, what would the charger do with that info. Unless a C>D>C was done, it wouldn't know where the cut capacity would be for it anyway, would it? Someone on the "other" forum suggested changing "Capacity" in the menu to "Cut Capacity", but how would that help unless a full CDC cycle was performed. Maybe I'm over thinking, but it would be interesting to find out.

It’s just a safety option to ensure the cell will not be overcharged or if you deliberately intend to restrict the amount of energy charged into a cell. According to the (German) manual a 20% surcharge to the expected/nominal capacity is a reasonable value to work with. I assume this option can also be set to “OFF” if not needed.