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

[kreisl]

v1.0 may or may not do any trickle charging

i am herewith confirming that v1.0 does trickle charging after discharge; i've measured it with NiMH battery, the trickle current is 2-4mA, average ~3mA:

and it also says so in the printed v1.0 instructions manual:

that's interesting.
and it is also interesting that the v2.1 doesn't do it anymore.

the question is: does it make sense to have/offer such a thing?

To me, it doesn't make real sense. And it is in fact contradictory to real discharge functions such as DISCHARGE REDUCE (see iCharger, MC3000).

 

[UnknownVT]

i am herewith confirming that v1.0 does trickle charging after discharge; i've measured it with NiMH battery, the trickle current is 2-4mA, average ~3mA
...
and it also says so in the printed v1.0 instructions manual

Ah! good catch (and confirmation).

My apologies, it seems v2.1 does trickle charge too -
v2.1 manual:


My observation was flawed - probably because the period was too short -
and/or the trickle charge current low enough that it made no difference to the readings.

Sorry for my misleading post.

 

[kreisl]

Thanks for the share Vincent, appreciated!
The LCD on my Opus says "0mA" too. But it is possible to measure the actual current, the trickling, with a multimeter, did you try it back then? Never mind.

Hobby chargers have a trickle charge parameter, for example iCharger offers {OFF|10|20|…|490|500}mA, and it is applicable to their CHARGE routines only. That makes sense. 30mA is a nice trickle charge rate to keep a normal battery at fully charged state. The Opus 3mA would be of little effect after a CHARGE routine; in turn this means that the "{OFF|10|20|…|490|500}mA" are absolutely not suitable for application after a DISCHARGE routine on a hobby charger, the rates are simply too high to keep a depleted battery at steady-state. With 10mA you could get a depleted AAA battery back to fully charged state after few days!

All that is helpful info. From that we are learning that "{OFF|10|20|…|490|500}mA" should only be applied to completed CHARGE routines, not DISCHARGE routines.

And to keep things simple and stupid, a TRICKLE CHARGE -neither 30mA nor 3mA- should imo not be applied to any completed DISCHARGE routine because it is really unnecessary. "preventing the batteries from discharging any further for NiMh and NiCd battery" — i don't believe that's an urgent argument.

 

[kosPap]

this is a very detailed video review of the charger (the 2nd part has it dissasembled)

https://www.youtube.com/watch?v=IA-MZZD7HEQ
https://www.youtube.com/watch?v=JJxrDgEFxMU

 

[realista]

if i open it and change the selector to 3,6v is it ok to charge 4x lifepo4 batteries ?

 

[StandardBattery]

if i open it and change the selector to 3,6v is it ok to charge 4x lifepo4 batteries ?

In theory, other people have done it with various versions of the charger, but I don't know that there has been an analysis of the charge cycle. I'd do one and check the termination voltage and then you could check the capacity.

 

[matt2]

I purchased this because I had a bunch of older AA's around and my cheapy charger doesn't test them. I put the charger on "quick test" but it doesn't seem that consistent. Is there something I need to be doing to make it more consistent or did I just receive a malfunctioning charger? One time it said 5000 or so, then 72, then 121. Can I trust it enough to throw out some of these older but costly batteries? It was basically bought to recondition them if possible and if not, give me a reliable way to tell me when and what to throw away.

 

[RI Chevy]

Welcome to the Forum! :welcome:

 

[StandardBattery]

I purchased this because I had a bunch of older AA's around and my cheapy charger doesn't test them. I put the charger on "quick test" but it doesn't seem that consistent. Is there something I need to be doing to make it more consistent or did I just receive a malfunctioning charger? One time it said 5000 or so, then 72, then 121. Can I trust it enough to throw out some of these older but costly batteries? It was basically bought to recondition them if possible and if not, give me a reliable way to tell me when and what to throw away.

Quick Test attempts to determine the internal resistance of the battery, it is very sensitive to battery contact resistance. Check HKJ's review on this changer for how this feature tested. It is likely sensitive to temperature and maybe current charge state. It should in general give some indication, but maybe just analyzing the discharge capacity is a better idea to get the current capacity of the cell, even if it can no longer be used for higher current applications.

 

[matt2]

Quick Test attempts to determine the internal resistance of the battery, it is very sensitive to battery contact resistance. Check HKJ's review on this changer for how this feature tested. It is likely sensitive to temperature and maybe current charge state. It should in general give some indication, but maybe just analyzing the discharge capacity is a better idea to get the current capacity of the cell, even if it can no longer be used for higher current applications.

Thanks. Is there a certain % of what mah is good for its rating? I have one showing 300mah after "discharge/test" but rated at 2400mah and quick test shows 1200. So I assume it's probably not even good for a clock, is it? I just have so many old ones and I'm trying to sort them out. I made a battery box, a small cardboard box with holes drilled in it so I can keep my AA's arranged and hopefully sort by health if I can figure out a good system. Do most people recycle? I hate to throw them away but it's a small town, I don't have a clue where to take them.

 

[StandardBattery]

Thanks. Is there a certain % of what mah is good for its rating? I have one showing 300mah after "discharge/test" but rated at 2400mah and quick test shows 1200. So I assume it's probably not even good for a clock, is it? I just have so many old ones and I'm trying to sort them out. I made a battery box, a small cardboard box with holes drilled in it so I can keep my AA's arranged and hopefully sort by health if I can figure out a good system. Do most people recycle? I hate to throw them away but it's a small town, I don't have a clue where to take them.

That one seems well done . Maybe others can give more guidelines but if mine are at 50% I consider them ready for recycling as it's not worth the cost or time to maintain them as they may miss termination during charging. I use devices to determine capacity maybe more than chargers. If they don't power the device for the time I need I'll try to revive them once and still probably move them to a lower power device. Then they go for recycle next time. I only consider LSD for low drain devices otherwise they need charging too often.

I hope most people recycle. Radio shack may still have recycle program, local fire stations often do. Ask around as many charities do it also.

 

[Tm98]

Most Home Depots or lowes has a recycling area for batteries.

 

[Tacoboy]

My BT-C3400 arrived a few days ago, so far I'm liking it.
But it's my first charger that I paid more then $10 for, so technically I have nothing to compare it to.

 

[InHisName]

I, too, charge / test all my old junk cells on it. I noticed that there seems to be an inconsistancy in what it does between successive charge / discharge cycles. One time I might discharge 1700 mAH, the next time the same cell discharges 27,567 mAH !! Obviously something has gone wrong with the 3100's methodolgy of calculations. HKJ, can you offer any explanations ? These odd discharge numbers have only occurred with the junkiest cells that I am attempting to categorize. BTW that cell above when in a low lumen flashlight, ran down in about the 90% of the hours I get from new Duraloops. So, that cell can put out up to 1700 mAH in low current demand devices. It's original mAH when I had it new & my C9000 was new, was 1977 mAH. It is a Duraloop that cycled weekly for 2 years, Then maybe 15-20 more in next 3 years. I'm guessing its at about 120 cycles of use, so far.

 

[HKJ]

HKJ, can you offer any explanations ?

I have a guess: The BT-C3100 works with pulses both during charge and discharge, these pulses are in the 2 to 3A range. If the battery is old it might have problems sustaining them and the charge may terminate a charge/discharge to early.

 

[ShineOnYouCrazyDiamond]

Hey - HKJ. There was a question in another charger recommendation thread about the 3100 vs the 3400. I had read in a review on Amazon someone saying that the 3400 was just the 3100 with the v2.1 rebranded as another model number for a particular manufacturer. Do you know anything about that?

 

[HKJ]

Hey - HKJ. There was a question in another charger recommendation thread about the 3100 vs the 3400. I had read in a review on Amazon someone saying that the 3400 was just the 3100 with the v2.1 rebranded as another model number for a particular manufacturer. Do you know anything about that?

I have also heard that the 3400 is just a rebrand of the 3100 V2.1 for a specific dealer.

 

[kreisl]

The BT-C3400 is a minimally improved version of the BT-C3100v2.1 and for exclusive sale by the US seller who is an electronics expert and charger maker himself . One can always drop him an email and ask about these minimal differences, yet i for my part finally did lo inconcebible for xmas and gave away my very last Opus unit (it was v1.0) to a dear friend :wave:. I had't been using the Opus much for months, glad now to have cleared space in my drawer. I liked it, DC1, but it has been factually replaced by my prototype units of DC2.

It was clever enough to release the early iterations v1.0 and v2.0 to market already and gather WWW feedback for further product refinement. The v2.1 seems mature and satisfactory enough for its price point (~35$ GB promotion) and hopefully Opus continues with the BT-C3xxx development as planned. The next notable iteration of the Opus charger model will have an external voltage switch and support 3.6V/4.35V chemistries officially so i will be looking into picking up one the 2015 model.

Fact is, it easily takes 2+ yrs to develop an advanced battery charger to full maturity status. Fans of DC1, DC2 and USC really need some patience including myself

 

[realista]

ehehee, they will sell the same charger but with "official" capability to charge 3,6 and 4,35v batteries....... imho just marketing.

 

[Tacoboy]

I've been using my new BT-C3400 almost non-stop for the pass week, been working fine.