Opus 3100 Question

Batteries and Chargers Chargers
1

What is the best way to discharge a fully charged lithium battery to the recommended storage level of 40-50%?

I have the Opus 3100 and I put a battery in , put it in discharge mode with all default settings. After about 2.5 hrs it seemed to stop at 3.4 volts. I placed the battery on my Miboxer charger and it read 5% charged.

Is there a way other than trial and error to get them at the 40-50% level?

I thought the Opus had a “storage” option so little user programming is needed.

Thanks

2

I don’t think you can with that charger … although the one I had nearly caused the house to burn down so I wouldn’t use one for anything let alone discharging which generates heat.

EDIT: Just stumbled across this in another thread so seems it can be set to a lower termination / storage charge of 3.7v but I’m guessing that’s for charging from empty … don’t know if the same can be set for termination on discharge

Still wouldn’t ever use one though!

3

If it’s the 3100 v. 2.2, you should be able to easily remove the bottom cover and locate a small slider switch on the right side of the PCB, when looking at the opened unit.

Mark out a dot over the slider and bore a 3/8ths inch hole and just use a toothpick to move the slider to the 3.7v setting and charge the depleted cells up to 3.7v.

Chris

4


I second that, Opus charges are not reliable (even dangerous)

5

IME and I’ve used my two 3400s for 7 and 3 years and they’ve been fabulous.

Maybe you bought a cheap knockoff, or just don’t know how to use it properly?

Chris

6


Unless I missed the "Do not catch fire" button, I think I know how to use it properly ;)

7

Unno, my 3100 is my go-to charger (got Nitecore, XTAR, Zanflare, almighty Miboxer, etc.), and it works fine.

And I always press the “Do not catch fire” button before using it.

8

Same experience, the OPUS is my ‘best’ over all charger. No problems.
NOTE - I DID upgrade the power supply (early supply was inadequate, it’s OK now). For years I regularly lubed the fan about every 3-4 months. I finally replaced it with an upgrade fan. The fan allows it to charge and discharge at a higher rate than a lot of other analyzing chargers by keeping it cool. If the fan sticks or fails this certainly could allow more heat (fire?).
IMO it works quite well.

Yes, you can take off the bottom and locate a switch for various chemistries. The lowest setting will charge a Li-on to storage, but you have to start below that level. I simply cut a window in the bottom to access the switch. Works fine.

Using % charge IN a charger can be frustratingly inaccurate due the various ways the voltage is measured. Hint - there is no standard.
Voltage is ‘good enough’ if you use a DVM. Anything from 40-60% is fine. I now target 40% instead of 50%.

9

I don’t know you from Adam, so I don’t know what you did, or what your Opus, legitimate, or a knockoff, did.

You made the comment that ‘they’re’ a bad charger and I disagreed, which is my experience.

My two Opus BT-3400 chargers have never caught fire, and work fine, but there are a lot of fakes out there.

With electronics, anything can crap out on you.

Chris

10

Yes it charges and discharges just fine when everything is OK.
But have you ever charged a bad cell and noticed the the Opus stop charging when the cell got too hot? Before that incident I was also convinced that it is a great charger.
I used it for charging and analyzing hundreds of cells but apparently you don't know if the thermal protection is really working until you notice the smoke coming out of it.

11

No, I’ve never noticed that because I can tell, using a few chargers, when my cells are near ‘end of life,’ so I don’t fret over it.

Sorry you had a problem, but don’t try and deal with ‘sketchy’ cells, to begin with.

Chris

12


It is like saying I don't care if my car's airbags are working properly, since I am a good driver. Accident my happen you may buy a new cell from decent seller and for some reason it will be defective or one of your cells may get wet or any other strange scenario.... It is always good to know that safety features are working "just in case".

I earn nothing from telling people that these chargers may be dangerous. I don't get paid by the competitors.
I just recommend you to check that your changer have functioning safety features before you find it out when it is too late

13

Dude, just send it back, or junk it for good?

They’re really good chargers, for not a lot of money and just chalk your experience up to you being an ‘outlier.’

Chris

14

Have you charged that specific ( I guess a near end-of-life, ultra high IR ) cell in another charger/analyzer that activated its temp sensor? If you did, I’d like to know what that is.

15


The cell, charger and other 3 cells that were charging at the same time became a mess of electrolytic and melted plastic, I am not that crazy to try charge it again, it went directly to the lithium recycling bin

16

That’s fine.

I assume, becuase of that incident, you looked for another brand of analyzer/charger that could have detected it.

If you have found one and really performed as you expected, could you share it here?