Help.. Opus BT-C3100 V2.2 Smart Universal LCD

is this charger capable of reading the capacity of 18650 batteries??


im planning of getting the 18650 from dead laptop battery and want to check the capacity of the battery..

Yes, only a rough guide though(tend to read a little too generous)and will need to discharge the cell and charge it ,to get a rough mah read out.

:welcome:

As "ven" stated, it is only the approximate capacity. The only way to get the approximate capacity is to fully discharge the cell using the Opus' discharge feature so that it is fully drained. I don't recall but I think the voltage goes down to about 2.7v when the Opus has discharged it. Then start the charge cycle and when it reports "full" at about 4.2v it will display the mAh it was charged with. That is how it works to the best of my recollection.

ven said:

Yes, only a rough guide though(tend to read a little too generous)and will need to discharge the cell and charge it ,to get a rough mah read out.

:welcome:

Click to expand...

Mine tends to be a little conservative. My 3400mah NCR18650Bs read at ~3200mah. Even still, from what I gather, newer versions of this charger only go down to ~3.0v when discharging causing even more conservative readings.

bwalker said:

As "ven" stated, it is only the approximate capacity. The only way to get the approximate capacity is to fully discharge the cell using the Opus' discharge feature so that it is fully drained. I don't recall but I think the voltage goes down to about 2.7v when the Opus has discharged it. Then start the charge cycle and when it reports "full" at about 4.2v it will display the mAh it was charged with. That is how it works to the best of my recollection.

Click to expand...

You don't have to manually do it, the charger has a Charge Test mode which will charge the cell fully, discharge it fully, then charge it fully again, displaying the measured capacity after the discharge.

Sir Lightalot said:

You don't have to manually do it, the charger has a Charge Test mode which will charge the cell fully, discharge it fully, then charge it fully again, displaying the measured capacity after the discharge.

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That's what I do. Always some pretty consistent results with a mixed mag of cells. Great charger!

markr6 said:

That's what I do. Always some pretty consistent results with a mixed mag of cells. Great charger!

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I have the same cells and got the same results on my v2.2 C3100 which has a 2.8v cut-off the v3.1 C3100 has an 3.1v cut-off i think :thinking:

John.

TinderBox (UK) said:

I have the same cells and got the same results on my v2.2 C3100 which has a 2.8v cut-off the v3.1 C3100 has an 3.1v cut-off i think :thinking:

John.

Click to expand...

Mine is also a v2.2, if that's what you were wondering.

bwalker said:

As "ven" stated, it is only the approximate capacity. The only way to get the approximate capacity is to fully discharge the cell using the Opus' discharge feature so that it is fully drained. I don't recall but I think the voltage goes down to about 2.7v when the Opus has discharged it. Then start the charge cycle and when it reports "full" at about 4.2v it will display the mAh it was charged with. That is how it works to the best of my recollection.

Click to expand...

Sir Lightalot said:

...
You don't have to manually do it, the charger has a Charge Test mode which will charge the cell fully, discharge it fully, then charge it fully again, displaying the measured capacity after the discharge.

Click to expand...

Exactly just use "Charge Test" mode and it will do everything for you and give you an approximate capacity value. Doesn't hurt to watch the temperature of the battery(ies) while doing this. If the charger won't recognize/charge a battery it has likely been discharged below a safe level and it's not worth trying to revive it, as that can be dangerous; especially if you're just trying to find cheap batteries and don't know much about them.

TinderBox (UK) said:

I have the same cells and got the same results on my v2.2 C3100 which has a 2.8v cut-off the v3.1 C3100 has an 3.1v cut-off i think :thinking:

John.

Click to expand...

Yes. Here's what a US seller said when asked "What does the newest version v3.1 offer over the older v2.2?":

"It is basically a change in the discharge for Li-ion cells. You will see the discharge for Li-ion cells terminate at 3.1V instead of 2.8V. This brings the charger in line with industry best practice for discharge. Most Li-ion cell data sheets specify 2.8V as minimum voltage for discharge. Best practice is to terminate discharge at 3.0V Because of the way this charger uses PWM for the discharge current it is better to use 3.1V.

In the past some low quality cells would trip the internal protect circuit, especially at high discharge currents. That was not so much a charger problem as it is a cell quality problem but the charger gets blamed. That situation is much improved now. The discharge and capacity measurement are now closer to industry best practice instead of just general Li-ion cell data sheet specifications. In fact the change has little affect in the measurements. The protocols for NiMH/NiCd cells are not changed."

I use the "charge test" mode quite often to determine if particular cells, usually older cells, are approaching the end of their service life. Bad cells can also be found by using the "Quick test" which measure the internal resistance.

In test mode, you are asked for a rate in MA, Just say i use 400ma is that use for both charge and discharge ??

Thanks

John.

TinderBox (UK) said:

In test mode, you are asked for a rate in MA, Just say i use 400ma is that use for both charge and discharge ??

Thanks

John.

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Yes that is correct. It's the La Crosse chargers that automatically cut your selected charge rate in half for the discharge rate.

Torchmee said:

Yes that is correct. It's the La Crosse chargers that automatically cut your selected charge rate in half for the discharge rate.

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I was afraid of that i am testing the capacity of some 14500 800mah cells an 0.2C discharge rate is 160ma so 200ma is the closest, but charging an 800mah cell at 200ma is a little lower than the 0.5C that is recomended.

Thanks

John.

TinderBox (UK) said:

I was afraid of that i am testing the capacity of some 14500 800mah cells an 0.2C discharge rate is 160ma so 200ma is the closest, but charging an 800mah cell at 200ma is a little lower than the 0.5C that is recomended.

Thanks

John.

Click to expand...

Why not just use your MC3000 then you can set any charge/discharge rate you want?

Torchmee said:

Why not just use your MC3000 then you can set any charge/discharge rate you want?

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I cannot be bothered to dig it out, Aslo it`s a bit big and not easy to keep out of the way of my cat`s
Plus i like to play with all my toys
John.

TinderBox (UK) said:

I cannot be bothered to dig it out, Aslo it`s a bit big and not easy to keep out of the way of my cat`s
Plus i like to play with all my toys
John.

Click to expand...

Have you compared the results on BT-3100 vs MC3000??
I have the BT-3100 and I'm thinking to buy a MC3000, and I would like to know the accuracy of both chargers...
Have you checked the voltage, current and capacity on both chargers??

Thanks!

cpa said:

Have you compared the results on BT-3100 vs MC3000??
I have the BT-3100 and I'm thinking to buy a MC3000, and I would like to know the accuracy of both chargers...
Have you checked the voltage, current and capacity on both chargers??

Thanks!

Click to expand...

ive got both
the mc -3000 is in a whole other league
you can actually take a good DMM, and calibrate it to .000 volt

I have both chargers, with the Opus starting from the 2.0, 2.1 and 2.2versions (among my other chargers as shown below)

The MC3000 has features that the Opus does not have, like complexity to operate ( some kind soul even went to the extent of making a 'cheat sheet' to just operate it more simple. This cheat sheet is something only available in video games that are designed by the game developer to be hard to conquer that a cheat sheet is made just to make it 'conquerable' for those who does not have the patience, or the ability to figure it out).

The MC3000 has also the ability to be coupled to a pc or smartphone for some fancy graphs (also a feature in my iCharger, which is guaranteed to be uninteresting once you know how such illustrated information can also be deduced from the digital read-out of both chargers), and some other small features to make battery charging a little more user-configurable, and be more than 2.5 times more expensive in price, for something that basically a Decent Charger/Analyzer like the Opus can also also do, like having four independent individual channel digital read-out display, basic charge/discharge/analyze etc., all available in both chargers.

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Thank you for yours replays...

tatasal said:

I have both chargers, with the Opus starting from the 2.0, 2.1 and 2.2versions.

The MC3000 has features that the Opus does not have, like complexity to operate ( some kind soul even went to the extent of making a 'cheat sheet' to just operate it more simple. This cheat sheet is something only available in video games that are designed by the game developer to be hard to conquer that a cheat sheet is made just to make it 'conquerable' for those who does not have the patience, or the ability to figure it out).

The MC3000 has also the ability to be coupled to a pc or smartphone for some fancy graphs (which is guaranteed to be forgotten once you know how such illustrated information can also be deduced from the digital read-out of both chargers), and some other small features to make battery charging a little more user-configurable, and be more than 2.5 times more expensive in price, for something that basically a Decent Charger/Analyzer like the Opus can also also do, like having four independent individual channel digital read-out display, basic charge/disharge/analyze etc., all available in both chargers.

Click to expand...

I know what you mean. And, what about the accuracy??... The Opus is really so accuracy than the MC3000??

By the other hand, with the MC3000 you can charge with a small current for small battery, and with the Opus just at 200mAh.

cpa said:

Thank you for yours replays...



I know what you mean. And, what about the accuracy??... The Opus is really so accuracy than the MC3000??

By the other hand, with the MC3000 you can charge with a small current for small battery, and with the Opus just at 200mAh.

Click to expand...

The MC3000 should be more accurate, and it must because it's more expensive by more than 2.5x, but it's not more than 2.5x more accurate....

With 200ma minimum charging current (I think this is what you mean), I don't know if there is a cell that would require a lesser recommended current than that (not that I know of) ...though the Opus will automatically drop down its charging current below what is set if the condition of the cell cannot immediately and safely handle it, and will eventually climb to the charging rate you set once it senses it is safe to do so.