Test/Review of Charger Opus BT-C3100 V2.1

[Arizona_Mike]

I'm going to double check my voltages but I think they are right on based on self discharge testing I've done on laptop cells. I never noticed a difference between the Opus and my multimeter.

I thought I'd read somewhere that the version 3.? only discharge tests to 3-something volts! 2.8 is plenty conservative in my opinion.

Mike

 

[oneof]

Hallo all, first time post here and longtime lurking.

Got a opus BT c3100 v2.2 and I am going through my old battery's....... Now a have the following set where something strange is going on....at least I think it is strange.....

4x 2600 GP Nimh

First time did a charge test

1379 mAh 1342 mAh. 1297 mAh 1389 mAh

Then I did a discharge refresh
In the same following

2602 mAh 2598 mAh 1703 mAh 2627 mAh

Now I could thing that the 3th battery is bad..but when it was doing it cycle in the charger it went up to 2624 so did it do a bad last charge.? Or is the battery bad?

Any info would be highly appreciated

Thanks

 

[tripplec]

I would not be concerned with that cell if it came up. You could do a few more cycles on it and see if stays up to capacity. If you are using the cells in pairs etc match it with one thats similar but for general use the capacity is much higher than the typical eneloop LSD.

 

[The-J-Man]

Changed the internal switch to 4.35v setting but when I put in a cell that at 4.2v it says full. Tried with all 3 of my c3100 V2.2 and it didnt work on any of them.
Any one know why?

the cells are ICR18650-30A /B

 

[ChrisGarrett]

Changed the internal switch to 4.35v setting but when I put in a cell that at 4.2v it says full. Tried with all 3 of my c3100 V2.2 and it didnt work on any of them.
Any one know why?

the cells are ICR18650-30A /B

Run them down to 4.00v, or less and then start over, seeing what you see.

I think people reported a starting cutoff voltage where it wouldn't charge up further, than where it was.

Chris

 

[tripplec]

Sounds like a software bug to me then. Any battery previous charged and unused even after a few hours place in another chargere EG my I4 will charge topping as the last LED is flashing and eventually finishing with all lights on. Same goes for my SH4 the other way around.

 

[ven]

Run them down to 4.00v, or less and then start over, seeing what you see.

I think people reported a starting cutoff voltage where it wouldn't charge up further, than where it was.

Chris

+1

Might get away with 4.1v as I have, but yes it won't top back up to 4.35v if the cell is near 4.2v. Been using mine regular for 4.35v cells of late now I know !

 

[The-J-Man]

Run them down to 4.00v, or less and then start over, seeing what you see.

I think people reported a starting cutoff voltage where it wouldn't charge up further, than where it was.

Chris

Thanks!! popped some cells in that were at a lower voltage and they charged to 4.35 just fine!

 

[markr6]

On my 3100 v2.2, I noticed when running a Test on 4 18650s, it went: 1000mA charge, discharge (didn't check rate), then 500mA for the final charge. I could have sworn it was 1000mA on the second charge other times I used this.

Update: never mind I just figured it out! When scrolling thru the screens I noticed all four bays say "418 mAh", which is impossible since they all started their second charging at different times. The charger obviously reset itself, maybe from getting too warm? Now that I think of it, I heard the fan get quiet and restart a couple times so I'm guessing it got too warm and restarted with the default 500mA. Same as if the power went out.

 

[fmc1]

Markr6


What you are seeing is also a classic symptom of an underrated or faulty power supply. It craps out exactly at the highest load point.


I had the same problem with my BT-C3100 V2.1. I was lucky because I was able to salvage a 12V 4A power supply from the trash. I had to change the output connector from a 5.5x2.5 to a 5.5x2.1 but it was no big deal. The reset issues all went away with the 4A power supply.


You could also stager the loading of each slot. That's what I did at first before I got the new PS. Put in one battery wait 15 min put in the next and so on. This way the transition from discharge to charge is at different times. This method helped but it was not a total cure.


Hopefully you have a supply from another device you can test with.

 

[Gauss163]

What you are seeing is also a classic symptom of an underrated or faulty power supply. It craps out exactly at the highest load point [...]

Yes, this was discussed at length on BLF starting around here. Many users fixed this by purchasing a $10 new high-quality 66W LITEON SMPS that I recommended.

 

[kosPap]

anyone knows how the charger handles deeply discharged batteries?

I just tried a 18650 showing 1.27V and the charger started charging as usual.

 

[tatasal]

anyone knows how the charger handles deeply discharged batteries?

I just tried a 18650 showing 1.27V and the charger started charging as usual.

It's a smart charger. If you choose a charging rate which is too high for the cell to safely accept it, the charger will automatically lower the charging rate to a safe level until the cell recovers and the charger then goes back up to the chosen charging rate.

For example, choosing a charging rate of 1A will not be followed by the charger until it senses that the cell can safely accept such rate. It will automatically hover between .1A to .3A... just click till the Display shows MA..you will see the charging rate as it progresses.

 

[Gauss163]

anyone knows how the charger handles deeply discharged batteries?

Most Li-ion chargers (likely including the BT-C3100) incorporate a precharge phase that attempts to safely recover cells that have been overdischarged. Typically cells are precharged at a very low rate (e.g. C/10), which helps to recover the crucial SEI passivating layer (which may have dissolved after long storage in a deeply-discharged state). Precharge usually terminates around 3V, at which time the normal CC/CV charge starts. If the precharge doesn't reach 3V in some configured time (e.g. half-hour) then an error is signaled (possible internal short, or other major failure). See this post for more on precharging.

Above the charge rate C/10 means Capacity over 10, so if they are 2500mAh Capacity then C/10 = 2500/10 = 250mA.

 

[kosPap]

thanks Gauss.
I thought most intelligent chargers did not allow recharging of an overdischarged cell. So it came as a surpise the Opus did.

 

[Gauss163]

thanks Gauss.
I thought most intelligent chargers did not allow recharging of an overdischarged cell. So it came as a surpise the Opus did.

It depends upon the depth of overdischarge. I don't recall the limits for the Opus, but if iirc they were mentioned in some of the earlier threads (and, of course, they can be determined by testing).

 

[TinderBox (UK)]

With firmware V2.2 it discharges 3.7v li-ion to 2.8 volts and firmware V3.1 discharges to 3.1 volts, It`s been a while since i used my C3100 V2.2 so i might be wrong.

John.

 

[joelbnyc]

This thread is giving me second thoughts on the Opus BT-C3100 V2.2 I just ordered...

Is this charger any use for measuring capacity? If not, can anyone recommend a capacity-measuring device or charger that is precise, accurate, and relatively user-friendly? Maybe the XTar VP4?

 

[ven]

The v2.2 is fine joel, if anything you get a more accurate reading. Most manufacturers state their MAH from min 2.5 or 2.7v, the v2.2 takes it down to 2.8v. The reason i believe they increased the voltage to 3.1v was due to issues with poor quality cells and PCB tripping.

 

[tatasal]

This thread is giving me second thoughts on the Opus BT-C3100 V2.2 I just ordered...

Is this charger any use for measuring capacity? If not, can anyone recommend a capacity-measuring device or charger that is precise, accurate, and relatively user-friendly? Maybe the XTar VP4?

The VP4 is just a 'straight-up' charger. It does not have the analyzing function like the Opus.

I have the Opus too and you can't go wrong with it. Very user-friendly! (and I have other analyzing chargers too like the SkyRC MC3000, etc. for that matter)

In the VP4, the channels are not independent of each other, unlike the Opus (different modes, rates, etc. can be set ALL at the same time regardless of battery chemistry).