Opus BT-C3100 v2.2 Issues?

Tesla101

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I bought a Opus BT-C3100 v2.2 and have been using it on the Discharge Refresh mode at 500mA for over 2 weeks with no issues at all.
Last night, I switched up to 1000mA on the Discharge Refresh mode, with 4 healthy 18650's and this morning came in to find that the supplied 12V/3A power supply had stopped working.

I've contacted the eBay seller for a replacement under warranty, but wanted to ask the community if anyone else has had any similar issues with this unit? Or am I just the unlucky guy? :!:

John
 
YEP! had one of mine blow 6 power supplies in six days - cut all the plug leads off attached to 12v rail of a computer psu and I'm golden and only one power point and none of those crap assed US to Aussie adaptors to deal with.
 
Thanks for the replies guys. I think I will go with the ATX power supply too :)

John
 
I Always keep atx powersupplys they are handy for al kind of projects.
You can get 12v 5v 3,3v out of them with a lot of amps.

Lux,
 
Great suggestion on the atx psu. I run 4 of these opus with the included supplies no problems. Think ill switch to an atx.

Another note, anyone opened one of these up, do they have a pot to calibrate voltage?
Wanted to check to sync all my units, just havnt bothered yet.
 
Hi,

I post this here rather than creating another thread about BT-C3100, if needed I can move it.

I recently got 2 BT-c3100 v2.2 to test capacity for my powerwall project and I found the readings a bit weird.
I didn't noticed it first testing 2800-3000 mAh battery, given capacity of 1500 to 2800 seemed good, but I retested some old Samsung 26H I previously tested with a copy Imax b6 months ago (a lot were 2400-2500 on Imax) and now I got 2600-2700 at 1amp with these BT-C3100, more than the rated capacity of theses old cells.

I'm a bit confused about the readings of theses chargers, I checked the discharge current with my multimeter and got 0.78-0.9Amp fluctuating for 0.999-1Amp given at the charger screen.
Can I assume the charger discharge below the rating it's supposed but think he's in the range and give a false capacity ?
I haven't found anyone with this concern with v2.2.A
 
Thx Paul,

I know that, but does it make sense to gain 10% capacity from 3V to 2.8V ? According to my little knowledge it's juste a few % max.

I checked again and my two units charges between 0.84 to 0.89Amp when the screen show .999-1.001. But this don't affect the tested capacity as it's during charging.
During the discharge process it's almost the same, around 0.87 to 0.91Amp for around 1Amp at screens.

So is it seems like a calibration problem, as it's almost the same rating during charge or discharge process, a week power adapter will only affect the charging. Am Iright ?
 
When charging with the Skilhunt M4D it gives 10-20% less capacity than what's previously discharged by the BT-C3100, % depending mostly of capacity and chemistry.
For exemple:
-Two identical cells will have the same capacity drop and the more high cap they are the more they drop most of the time, like 10% until 2000mah, 20% on some 2600+.
-Two 2200 mah discharged on the BT-C3100 but different brand/model can result one 2100 and the other 1950 charge on M4D.

So both my bt-C3100 give false capacity, but I will keep them as discharger, if all my cells are tested the same way it should be ok for a powerwall but I have to keep in mind they can't be trusted for small packs of different cells.
 
Yes, I know, and it's pretty close when I re-run a test, the problem is they always give too much capacity, a 5-10 year's old Samsung 26F can't give 2700-2800Mah at 1Amp.
BT-C3100 V2.2 stop discharge at 2.8v but capacity between 3V and 2.8V is almost null and most batteries fall from 3.1 to 2.8 in less than a couple of minutes.

Imax is one cell at the time so I need the two bt-c3100 to have 8 channels to test capacity.
 
Hi I had my Opus BT-C3100 blow up on me last night while discharging my current collection of batteries; then did that mad dash around the room while 50+ plus batteries are charging because I can smell 'magic smoke', then waving my IR thermometer around like a mad man. Only to find smoke pouring out of of the back of the opus where to DC connector plugs in. I unplugged and took the back off and found the PCB sparking and the display flashing (indicating a buggered PSU) and possible an arcing track on the power in track. Needless to say it's about 2 weeks old, and I've contacted the ebay seller.
 
Wow!!! that's nuts!! Umm, you didn't get it on video, did you? :rolleyes: I would of loved to see you running around like a madman :p

It sucks that the opus died. However, it's better the opus than the cells, imho. Cells could cause lots of fires as they like to explode and fling across the room and land in a place you absolutely can't get to as it found the 'only' too small to get into and can it before it runs rampant. And no, not from experience. Just thinking of what "could" of happened.
Glad nothing major happened, just a little excitement
 
Use the number from the charger as a number. Ie just stating in what bin you should throw them. If that number is 10% to much or 100% to much its a way to tell at what state the cell is in. We all know that it is 10-20% higher than some other but it also depends on what charger you do compare to and more importantly what voltages. First of all the opus tend to go a bit high and then it also goes very very low. Compare to some others that stop rather early at both ends :) (If you want to compare full capacity)

The last cells i got new for testing they all had their capacity measured between 4.2 and 2.5V and at 0.2C... Thats quite a difference to what most of us will be running in real life :)
 
The reason these chargers eat power supplies is because (electrically speaking) it uses the power supply as a hammer to beat the batteries to death with. There are some detailed reviews around, which show they draw peak currents between 6 and 9 amps from a 3 amp supply.

When charging, even at 200mA, they are blasting pulses of 2.4 amps into the battery.
When discharging, irrespective of the current selected, they are drawing pulses of 3.5 amps from the battery.

I think this is also why they give wildly inaccurate discharge currents - they're not discharging at a constant current. and the formula used to convert the peak current to RMS current changes with the pulse width. Either the algorithms aren't up to the job or the pulsing is messing with the battery chemistry. At 1 amp charge, I measured 950mA DC and 1.2amps AC. I'm no expert on charging lithium but I know that kind of ripple on a thonking great 12v AGM lead acid will void your warranty. It can't be healthy for a little old 18650.

I know that lithium is supposed to be charged at a constant current and then constant voltage - this charger produces neither and is about as constant as a hammer banging in a nail.

My other 3 chargers produce reasonably comparable discharge figures. This one is a bit of a rouge and is always optimistic by 20-40%. It's not so bad if this is your only model and you are only grading batteries, but you just can't use this one in combination with any other brands.

If you haven't already bought one of these, I'd recommend giving this model a miss. It is a shame because they are almost a brilliant charger - the physical construction is nice, the features are good, but who ever designed the electronics needs to go back to school and needs to calibrate their multimeter.
 
Do you have a site that has more information about this?
 
I recently witnessed something strange while charging cells with my MC3000s. This is a possible explanation.

I have three of them and used their original power supplies at first. These are rated for 50W and got surprisingly warm when charging four cells at 1A each. I then modded the MC3000s a bit and power them from an ATX PSU now. Because I had some excess solar power I connected the PSU to my Inverter where I always have a wattmeter at its output. Turns out the PSU peaks at over 70W at its input while three MC3000s charge four cells each at 1A max. I thought that this is a bit too much really given the known effciency of charging cells and the known efficiency of the PSU which is well over 85%
However, this wasn't the only thing. power consumption was also very unsteady. Over one or two hours I saw all kinds of numbers on the meter, most of which made no sense to me whatsoever. They do now, maybe the MC3000 does exactly the same thing as the Opus while charging.
 
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