SkyRC — IFA 2014 — MC3000 charger-analyzer

[linc90]

Nothing is wrong. In regards to the resting cell it's perfectly normal for a healthy cell to recover that much voltage after cutting out at 2.7v 1A . As for the cells almost finished, you are simply observing how little capacity is left in these particular cells below 3v.

 

[linc90]

Just to clarify you can see cells 3,4 are still discharging by the negative sign on the current measurement eg, -1.01 as opposed to cell 2 which has 1 amp going into it which means it finished discharging first and has now started charging.
One reason it might have done that is if it was more changed than the rest when you started the cycle since you have it setup c>d>c (charge,discharge, charge)

 

[SYZYGY]

i see. yeah i guess it's possible that it really did discharge to 2.7V, and i wasn't around to observe it in time. i'll pay better attention. thanks!

 

[linc90]

You're settings are correct and I've never seen this charger get it wrong, so it's basically a guarantee that it did discharge to 2.7v.

 

[SYZYGY]

how's this storage profile?

BATT TYPE: liion
MODE: storage
CAPACITY: 4200mAh
C. CURRENT: 1A
D. CURRENT: -1A
C. RESTING: 0min
D.RESTING: 0min
CYCLE COUNT: off
CYCLE MODE: off
TARGET VOLT: 3.80V
TERMINATION: 0.01A
RESTART VOLT: OFF
D. REDUCE: -ZERO
CUT VOLT: OFF
CUT TEMP: 45°C
CUT TIME: OFF

maybe it doesn't matter in the end, but it didn't finish even after 6 hours. the slots were still busy.

i think default termination for storage is Zero, and i read somewhere that setting it to 0.01A or 0.02A can help with the profile taking longer than it needs to. i don't actually understand why, though. should i try increasing it to 0.02A?

also, what's with skyrc's choice of 3.8V for storage? everything i've read i the past suggests 3.6-3.7V. guessing 3.6,3.7,3.8 are all close enough, and it doesn't really matter. as long as it's stored somewhere around half full it's ok?

 

[linc90]

I've heard reports of this to. Haven't had this problem myself, I think it would depend on the particular cell. Definitely try raising it up a bit. But you're right it doesn't matter at all, after 6 hours they will be as close to 3.8v as they will get.

 

[linc90]

Oh yeah somewhere around that voltage will do. It really depends on the cell where exactly halfway is and doesn't have to be that accurate I believe.

 

[SYZYGY]

thanks for your patience.

got another one:

slot 4 is running this program:

NCR18650GA Storage

BATT TYPE: LiIon
MODE: Storage
CAPACITY: 4200mAh
C. CURRENT: 1.25A
D. CURRENT: -1.5A
C. RESTING: 0min
D.RESTING: 0min
CYCLE COUNT: OFF
CYCLE MODE: OFF
TARGET VOLT: 3.75V
TERMINATION: 0.02A
RESTART VOLT: OFF
D. REDUCE: -Zero
CUT VOLT: OFF
CUT TEMP: 45°C
CUT TIME: OFF

i'm putting some fully charged cells into storage, but it seems to discharge at -1A despite D. CURRENT being set to -1.5A. thoughts?

 

[linc90]

Oh that's an easy one, mc300 will only discharge up to 2 amps if only 1 slot is getting used, if more than one slot is active it is limited to 1 amp discharge per slot as not to overheat the charger.

 

[SYZYGY]

i'm using eneloop pro AAs

BATT TYPE: NiMH
MODE: Charge
CAPACITY: 2700mAh
C. CURRENT: 1.00A
D. CURRENT: OFF
C. RESTING: 0min
D.RESTING: OFF
CYCLE COUNT: OFF
CYCLE MODE: OFF
TARGET VOLT: 1.65V
DELTA PEAK: 3mV
TRICKLE C.: OFF
TRICKLE TIME: OFF
RESTART VOLT: OFF
D. REDUCE: OFF
CUT VOLT: OFF
CUT TEMP: 45°C
CUT TIME: OFF

according to the packaging, these can supply up to 2550 mAh:

anyone have a profile for these they'd like to share? does mine look good?

when i use this profile, i encounter the Capacity Cut error:

Capacity: 2700mAh
Voltage: 1.52/1.65V
Average: 1.458V
Energy: 3.931Wh
Time: 2:50
Batt IR: 73mohm

i hesitate to increase it by too much more without advice from you guys. should i set it to 3000 mAh?

thanks

 

[Gaudi]

Capacity Cut means that the charger is not detecting the charging ending point, probably because the charging current is a little bit too low, or there are other issues. You can set it a little bit higher, usually 0.5C, which is about 1.5-1.8 A for your batteries.

You can disable the Capacity Cutoff (make sure you are around to detect any issue/overcharging in case the batteries are damaged).

From Google: "The charge algorithm for NiMH, using negative Delta V to detect full charge is delicate, especially when charging at less than 0.5C. A mismatched battery pack or a heated one further reduces the symptoms. NDV in a NiMH charger should respond to a voltage drop of 5mV or less."

 

[Geppo]

Capacity: 2700mAh
Voltage: 1.52/1.65V
Average: 1.458V
Energy: 3.931Wh
Time: 2:50
Batt IR: 73mohm

i hesitate to increase it by too much more without advice from you guys. should i set it to 3000 mAh?

thanks

You set a capacity cut value too low. Use Nominal Capacity x 1.2, then 3100mAh for Eneloop Pro AA batteries.
Anyway Gaudi's suggestions are right. If you set Delta Peak=3mV you should use 0.5C as charging current (as clearly stated by Panasonic).
Alternatevely (like I do) set Delta Peak=0dV and generally you can lower the charging current down to 0.3C.
The MC3000 charger uses a constant current charging method (not pulsed) and it is quite critical regarding the detection of the end charging point.

 

[dma_k]

From Charger SkyRC MC3000:

Be careful with charge current, using anything below 0.3C will probably miss termination on AA/AAA cells. I mostly use around 0.5C.
To keep the cells safe if the terminations is missed use a capacity limit between 130% and 150% of the cells capacity and a timer cutoff calculated as ''capacity/current×1.4'', i.e. for a 2000mA cell at 1A it is 2000/1000*1.4 = 2.8 hours = 2 hours 48 minutes.
For NiMH the -dv/dt setting must be as low as possible, I used 3mV for my test, but a lower value might be even better. Too low value will not damage the cell, but might give early termination.
LSD cells do not need any trickle charge, for other cells a 10mA trickle charge can be used, but it not really needed either (some manufactures recommend a time limited trickle charge after a -dv/dt charge).

 

[SYZYGY]

thanks. for my 2550mAh eneloop pro AAs, i'll try changing from this:

BATT TYPE: NiMH
MODE: Charge
CAPACITY: 2700mAh
C. CURRENT: 1.00A
D. CURRENT: OFF
C. RESTING: 0min
D.RESTING: OFF
CYCLE COUNT: OFF
CYCLE MODE: OFF
TARGET VOLT: 1.65V
DELTA PEAK: 3mV
TRICKLE C.: OFF
TRICKLE TIME: OFF
RESTART VOLT: OFF
D. REDUCE: OFF
CUT VOLT: OFF
CUT TEMP: 45°C
CUT TIME: OFF

to this:

BATT TYPE: NiMH
MODE: Charge
CAPACITY: 3100mAh (1.2x)
C. CURRENT: 1.30A (0.5C)
D. CURRENT: OFF
C. RESTING: 0min
D.RESTING: OFF
CYCLE COUNT: OFF
CYCLE MODE: OFF
TARGET VOLT: 1.65V
DELTA PEAK: 3mV
TRICKLE C.: OFF
TRICKLE TIME: OFF
RESTART VOLT: OFF
D. REDUCE: OFF
CUT VOLT: OFF
CUT TEMP: 45°C
CUT TIME: 165min (C/I*1.4 = 2550mAh/1300mA*1.4 = 2.75h)

 

[Geppo]

Anyway, worn batteries could exhibit a different behavior, missing the end of charge point. As far as I could see, you can get a better behavior lowering delta peak down to 0V (and lowering a bit the charging current).

 

[tjh]

I'm in the market for a new AA/AAA/LiIon charger.
Is the MC3000 still the best beast to get for someone (like me) who loves to fiddle with everything?

 

[mactavish]

I'm in the market for a new AA/AAA/LiIon charger.
Is the MC3000 still the best beast to get for someone (like me) who loves to fiddle with everything?

If there is a better one, I'd be curious. I don't recommend it for those that just want an auto everything unit. If you like learning all the available settings, and dealing with the interface, it's great. Having a bit of battery charging knowledge beforehand is helpful.

 

[tjh]

If there is a better one, I'd be curious. I don't recommend it for those that just want an auto everything unit. If you like learning all the available settings, and dealing with the interface, it's great. Having a bit of battery charging knowledge beforehand is helpful.

Oh, I had one for years. Loved it. If you read back in this thread you'll see I had to help a bunch of people who thought they'd bricked their charger when they did a FW upgrade. I had the very first version, I even did the fan mod to help keep it cooler, but in the end the plastic posts snapped. I'm thinking of getting another one - but I just wondered before I drop the $$$ on it (it seems to have almost doubled in price since I bought it, but I think I got an earlybird discount maybe) if there was something out there even more nerdy

 

[hc900]

He has a flaw evident:
While with pulse charging type BT-C700 things usually go well, with adequate current the charging of AA batteries ends quite well.

With constant current charging, the MC3000 has problems finishing the charge: the -Delta V at 0mV works with certain 2500mAh batteries, but with other batteries the charging ends at 60%. In this case the recharge must be set with -Delta V at 3mV.
In other cases, if the charging current is low, such as 400mA, the substantial risk is to go well beyond 100% with obvious consequences.

My conclusion is that with the MC3000 I have to:
1] do some recharging tests with any type of AA or AAA battery
2] write down all problems
3] set the type of recharge in the memory for each brand of batteries
4] set the right current for each model
5] set the -Delta V for each model
6] set the safety timer for each model

The alternative would be to buy only one type of battery, such as Eneloop:
as on the famous HKJ tests, without wasting time analyzing all the possible complications.

Ultimately, with NiMh batteries this is not a fully automatic and foolproof charger.

 

[linc90]

I recharge quite a lot of different brand aa and aaa nimh on my mc3000. With new cells and healthy cells I never have a problem at all. Only with worn out or very poon health batterys fail to terminate correctly for me.