SkyRC — IFA 2014 — MC3000 charger-analyzer

[Schermann]

Great review and thread!

 

[-Archie-]

I'd like to share my modification of MC3000: maybe it will be useful for some users.

Main problem was overheating: simultaneous testing of four 18650 cells at 1A discharge rate was impossible. I've added two 30mm Sunon fans to the rear wall, one of them mounted in opposite direction - so they make transient air flow.

They're controlled by thermal switch circuit, with sensor attached to the radiator: as soon as its temperature exceed ~35°C the fans are actuated. Now I can use all four slots without any problems.

Unstable sliding contacts fixed by bypass wires: extra-soft silicone cables are attached to the negative terminals:

Common problem of fragile plastic pins for spring mount resolved by using M2.5 screws instead. Cross-shaped heads successfully replace circled + signs BTW. Screw ends are going through PCB and fixed with Nyloc nuts to prevent loosening:

Turned out it's handy to insulate screw heads (e.g. with Kapton tape), as accidental contact with positive cell terminal will destroy the spring.

After assembling, thermal sensor holes filled with thermal paste, and narrow strips of thermal-conductive silicone affixed to the metal bands, to improve heat transfer:

Also, I've added sockets for 1st. slot to connect any non-round cells, and MiniDIN-6 socket to connect ST-Link for easy programming/debugging without using USB method:

 

[marco.weiss]

WOW!

 

[tjh]

Farewell.

My first gen MC3000 had it's first post snap yesterday. I opened it up and it was tiny bits of plastic everywhere.

Alas. I threw it in the rubbish.

I'll get another one one-day, it was a superb charger and I'll miss it.

 

[-Archie-]

Throw away $100 charger because of snapped pin?!? Unbelievable...

 

[tjh]

Throw away $100 charger because of snapped pin?!? Unbelievable...

Why? I couldn't put it back together. It was in pieces, it was very broken (so many little bits of broken plastic - it had obviously degraded badly) and I've got a Dragon VP4 Plus that I use anyway.

It's a shame, but I wasn't going to spend hours putting a broken piece of kit back together.

 

[-Archie-]

Ok, it's not my business of course - just looks illogical to me. But I do agree the plastic used for MC3000 case is a garbage.

 

[Dascombe]

I'd like to share my modification of MC3000: maybe it will be useful for some users.


Unstable sliding contacts fixed by bypass wires: extra-soft silicone cables are attached to the negative terminals:

View attachment 15282

Very nice work Archie!

What's your thoughts on the wire bypass mod? Do you find it makes much of a difference with IR measurements?

 

[-Archie-]

Thank you!
Main intention was, to minimize voltage errors on discharge. IR measurement in MC3000 is a joke anyway: four-wire scheme is needed to do it properly. But after modding, the deviation of displayed IR values on several subsequent "measurements" was greatly reduced as well, as expected.

 

[radellaf]

Nice mod! Bit of work, but if I ever have to open it up to repair a spring post maybe I'll do that.

The IR measurement is, eh, good enough to tell if your cells are starting to get old. I don't trust 50 vs 100, but if it starts saying my eneloop is 200+ then I know the Zebralight SC53 isn't going to like them. If I want to evaluate 18650 for if they're counterfeit or if my 2 y.o. cell can handle ridiculous high currents, then, yeah, MC3000 isn't great. I got a high reading on an old 14500 (like 200-300?) and was convinced to buy some new ones.

 

[-Archie-]

Nice mod! Bit of work, but if I ever have to open it up to repair a spring post maybe I'll do that.

Thanks!

The IR measurement is, eh, good enough to tell if your cells are starting to get old.

Or it's time to clean the terminals, or to check with more serious tool...

Example from my records: five LG B1 cells (datasheet claims ≤ 70 mΩ) checked with 4-wire Kelvin circuit and with unmodified MC3000:

59.5 == 191
59.2 == 337
58.2 == 198
58.4 == 249
58.3 == 138

It's nice to have that data on MC3000 display, but when it looks incorrect - don't relay on them to make the decision to discard the cell in question: it's better to double-check.

 

[STIXXXXX]

Hi, I´m reading this thread since the beginning, and love the MC3000. Had all hardware versions and the last one shows a weird behaviour:
When inserting 4 cells into the slots, all voltages are nearly the same, but when charging starts, the first slot voltage increases way faster than the other ones. The cell will be charged but takes longer and does only take around 90% of charge.
LiIon or Nimh doesnt make a difference.
Some ideas?
Just ordered the EBL TC-X Pro, because I like the touchscreen, but I miss 1A discharge and presets.

 

[-Archie-]

the first slot voltage increases way faster than the other ones. The cell will be charged but takes longer

Seems contradicting to me.

 

[STIXXXXX]

Seems contradicting to me.

That was, what I saw with LiIon batteries. Voltage increased very fast, so that the current was reduced earlier -> longer charging..

 

[panasonicst60]

Had a problem with my mc3000 earlier today. When I put in four enoloop aaa batteries to charge, two of them started charging, but the other two said no battery message. I switched out the slots and it still didn't work. I changed them for a few minutes on the oem Panasonic charger then placed them back into the mc3000 and then it was recognized with a battery and charged without further issues. How can I fix this issue. Was it drain so low that the mc3000 didn't detect a battery?

 

[Vasilije]

Had a problem with my mc3000 earlier today. When I put in four enoloop aaa batteries to charge, two of them started charging, but the other two said no battery message. I switched out the slots and it still didn't work. I changed them for a few minutes on the oem Panasonic charger then placed them back into the mc3000 and then it was recognized with a battery and charged without further issues. How can I fix this issue. Was it drain so low that the mc3000 didn't detect a battery?

Holding the slot button in which the battery does not have enough voltage forces the charging so that the charger accepts it and allows it to start a normal charging cycle.

 

[sbj]

It could have been due to a bad contact on the minus side?

With the small diameter of the AAA batteries, it can easily happen that the negative pole of the battery does not make proper contact with the sliding contact of the charger.

https://www.candlepowerforums.com/t...—-mc3000-charger-analyzer.389700/post-4813931

When inserting AAA batteries, I have got used to lifting the minus side of the battery slightly after inserting it.

 

[panasonicst60]

It could have been due to a bad contact on the minus side?

With the small diameter of the AAA batteries, it can easily happen that the negative pole of the battery does not make proper contact with the sliding contact of the charger.

https://www.candlepowerforums.com/threads/skyrc-—-ifa-2014-—-mc3000-charger-analyzer.389700/post-4813931

When inserting AAA batteries, I have got used to lifting the minus side of the battery slightly after inserting it.

No I verified it's not the reason. It charges up without any issues now that the battery is not low.

 

[wus]

When inserting 4 cells into the slots, all voltages are nearly the same, but when charging starts, the first slot voltage increases way faster than the other ones. The cell will be charged but takes longer and does only take around 90% of charge.
LiIon or Nimh doesnt make a difference.
Some ideas?

My guess: channel 1 has some unwanted resistance in its path. Did you clean the contacts?

 

[wus]

When inserting 4 cells into the slots, all voltages are nearly the same, but when charging starts, the first slot voltage increases way faster than the other ones. The cell will be charged but takes longer and does only take around 90% of charge.
LiIon or Nimh doesnt make a difference.
Some ideas?

My guess: channel 1 has some unwanted resistance in its path.