Review: Opus BT-C3100 ("dreamcharger!")

B25364 - I need only one, but for the price of 15$, shipped, I would gladly accept two :D!

UPz - thanks for your work, I understand that as detailed reviews as yours are hard to translate due to large amount of data/words ;)! I will take a look at Google translated ones :D!

Very interested.

Interesting video from one of the well known “electronic” guys (along with EEVblog/Dave and mikeselectricstuff) on youtube

Nice review. He didn’t test for some of the issues HKJ found in his model though, but measurement differences and fluctuations of current seem to indicate maybe they are still there.

Yes for $15 I think many here would buy several :slight_smile: *especially if some of the issues are corrected. I would be cautious about charging some of my more expensive batteries in it so as not to reduce capacity, and I can see off/on fan constantly as particularly a potential annoyance.

Another technical review of the charger has appeared, interesting!
http://www.mountainprophet.de/2014/03/15/preview-akkulader-opus-bt-c3100/

The spike he found is interesting, although he is using the undocumented 4.35V option (charging two cells at 2A). I would be concerned if this and the power cycling happened at 4.2V.

Chloe,

the spike was recorded at 4.20V. Charger resets were observed at 4.35V.

The price is not good yet.

http://www.aliexpress.com/wholesale?SearchText=bt-c3100&catId=&initiative_id=SB_20140321233102

There is a group buy on German forum TLF, cost ~40€:

Is that a group buy for the corrected version of the charger?

A google search came up with another technical review of the early BT-C3100, says "Preview":

http://www.mountainprophet.de/2014/03/15/preview-akkulader-opus-bt-c3100/

Yes, if you click the Google docs link in the TLF post it says new firmware including error correction. The voltage switch remains internal.

€ 43.85 = $60.49 So their group buy price of 40 units is the same as a single Aliexpress unit shipped to usa. I wonder what we could get the price down to? Maybe just waiting a month or two will lower the price of them a lot.

- Joe

Ouch $60 with only 2x26650, no 32650, max of 2A with spikes too, so $120 to charge big multi cell lights at once?? Bye bye to the “dreamcharger”, its turning into a nightmare. :stuck_out_tongue:

I’m not sure I’d call it a nightmare. I paid about $35 for a Lacrosse BC700 that only does AA and AAA that I love. This is the same thing, but it will also do my 18650 and 14500 cells. It would save me from buying a hobby charger, and then rigging it to do discharges and other things. I wish it was more like $40-$50 but I will end up with one eventually. I will wait a bit though and see how the price changes. I think our uses for it are different. I have nothing larger than an 18650. I want it for discharging and doing capacity testing of 18650s and such. Things that you’d normally need to buy a hobby charger for, and then hack it so it does single cells.

- Joe

Yeah I’m responding to the drama with which we were promoted this “dreamcharger” for months to wait to purchase :wink: Its not horrible, but for the price I wouldn’t get it, and for my use, the use that this was promoted to solve for me, its poor. For a multi chemistry person I guess its OK. *as long as you are only charging 18650/smaller cells. But that’s not what I want it for, I have other chargers for that. This was promoted as a solution for the big multi cell lights, which it is most certainly not. 2x TR-008 is a much better option for price at $30 each, but then they have a charge dip during charging and HKJ noted some over-voltage at times…keep on dreaming for a dreamcharger I guess.

Banggood have “Powerfocus” branded ‘BC3100’ (58.69 USD).:

Also listed, C/D cell adaptors, like in the BT-C2000 :

Well, that didnt take TOO long to finally go on sale :D!

And those C/D adapters are chepaest ones Ive seen!

They say, the best things come to those who wait… :wink:

Price is still nowhere near the 25°C group price!!

http://www.hkequipment.net/index.php?p=6&id=2041

What does that mean? Its $62.99 on that site?