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

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

Chloe
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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.

sk4477
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Chloe,

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

Let-There-Be-Light
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Chloe
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There is a group buy on German forum TLF, cost ~40€:
http://www.taschenlampen-forum.de/ladegeraete/32083-opus-bt-c3100-dreamc...

pipifax
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Chloe wrote:
There is a group buy on German forum TLF, cost ~40€: http://www.taschenlampen-forum.de/ladegeraete/32083-opus-bt-c3100-dreamc...

 

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/

Chloe
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pipifax wrote:
Is that a group buy for the corrected version of the charger?

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

Quote:
Neue Firmware Lt. Hersteller Opus inkl. Fehlerkorrektur Schalter bleibt Intern!

Let-There-Be-Light
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Chloe wrote:
There is a group buy on German forum TLF, cost ~40€: http://www.taschenlampen-forum.de/ladegeraete/32083-opus-bt-c3100-dreamc...

€ 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

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Ouch $60 with only 2×26650, 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. Silly

Let-There-Be-Light
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B42 wrote:
Ouch $60 with only 2×26650, 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. Silly

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

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Let-There-Be-Light wrote:
B42 wrote:
Ouch $60 with only 2×26650, 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. Silly

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.

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Banggood have “Powerfocus” branded ‘BC3100’ (58.69 USD).:
http://www.banggood.com/Powerfocus-BC3100-Ni-Mh-Lithium-ion-Battery-Char...

Also listed, C/D cell adaptors, like in the BT-C2000 :
http://www.banggood.com/Powerfocus-D-C-To-AA-Cell-Adapter-For-Ni-mh-Batt...

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

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

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

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

 

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

B42
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pipifax wrote:

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

 

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

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

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Is the spike still an issue? I'm not clear on all this. Looks like a great charger other than that issue.

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That Powerfocus is too expensive unless it's revised and working properly.

The low mode should be lower.

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so anyone already arrange a group buy for this charger?

pipifax
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i cannot reach the bogus website powerfocus.net Cry

This URL has much commercial material about the product?

http://item.jd.com/1077609865.html

 

What does it say, it it the revised version of Chloe's product? Smile

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pipifax wrote:

i cannot reach the bogus website powerfocus.net Cry

This URL has much commercial material about the product?

http://item.jd.com/1077609865.html

 

What does it say, it it the revised version of Chloe’s product? Smile

Hopefully it’s the fixed one. There is a fixed firmware according to post #127. Google Translate gives me a headache though.

- Joe

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I thinks the group buy fir this charger just started:

http://budgetlightforum.com/node/30515#new

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Chloe wrote:
pipifax wrote:
Is that a group buy for the corrected version of the charger?
Yes, if you click the Google docs link in the TLF post it says new firmware including error correction.

Hi Chloe

The main issues found by HKJ was:

- The charger is oscillating and stops the charging a bit too premature

- The "resting"/overheating periods during 2A charging or 4 x 1A discharge

- Power spikes from the power supply

- Uses trickle charging for NiMH when cell is fully charged

 

Do you know if all the issues above have been fixed, or only some of them?

Is there a way of determining whether a charger has got the revised firmware?

Thanx

Current Collection:

BLF: BLF-GT90, BLF-GT70 (CW Sliced), BLF GTmini, BLF-LT1; 

BTU: Shocker (3 x SST-40 @ 8A)

Solarforce: L2P (XM-L2 U3 @ 4A), MPP-1 (XP-L HI @ 6A), MPP-3 (3 x XM-L2 U2 @ 12A), M6 (Nichia 319A @ 6A), M8 (XHP-50.2 @ 9A), 9x (9 x XM-L2 U2 @ 2A)

Coming Soon: Lumintop: BLF-GT4; 

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Lothar wrote:

Chloe wrote:
pipifax wrote:
Is that a group buy for the corrected version of the charger?
Yes, if you click the Google docs link in the TLF post it says new firmware including error correction.

Hi Chloe

The main issues found by HKJ was:

- The charger is oscillating and stops the charging a bit too premature

- The “resting”/overheating periods during 2A charging or 4 × 1A discharge

- Power spikes from the power supply

- Uses trickle charging for NiMH when cell is fully charged

 

Do you know if all the issues above have been fixed, or only some of them?

Is there a way of determining whether a charger has got the revised firmware?

Thanx

I have sent to Dora of Gearbest a copy of HKJ’s CONCLUSION section of his review.
Dora will forward it to Opus for their perusal.

Henry Xu
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1. The charger is oscillating and stops the charging a bit too premature
This has been solved by firmware update: charger will make no current increase back in the CV stage. So no oscillating at all circumstances.

2.The “resting”/overheating periods during 2A charging or 4 × 1A discharge

2A charging is supposed to be used for high capacity Li-ion batteries, we should mention this in user manual that charging with ni-mh AA batteries with 2A charging current is not appropriate. Since 1A discharge current for 4 pcs li-ion batteries will generate a lot heat, and the fan exhausting speed is not fast enough.So it can lead to thermo-protection kicked in, which this safety mechanism is designed for. So I hope it is acceptable. If only two batteries is discharged at 1A speed, it should be no problem.

3. Power spikes from the power supply
We noticed for 9A peak current with very little period time of less than 10ms. we improved this problem by adding a larger enough filtering capacitor and its peak current now is reduced to 7A. The problem is not 100% solved, however it is improving the power supply quality significantly.

4. Uses trickle charging for NiMH when cell is fully charged
I think trickle charging current for nimh is necessary. And we believe this is a good feature of this charger. We have no plan to take this trickle charging away for nimh batteries. For li-ion batteries, there is no trickle charge current.

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Thank you, Henry!

Icon
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Excuse my ignorance on such things, but this says it will discharge, does that mean it will set a charge for storage?

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Henry Xu wrote:
1. The charger is oscillating and stops the charging a bit too premature
This has been solved by firmware update: charger will make no current increase back in the CV stage. So no oscillating at all circumstances.

2.The “resting”/overheating periods during 2A charging or 4 × 1A discharge

2A charging is supposed to be used for high capacity Li-ion batteries, we should mention this in user manual that charging with ni-mh AA batteries with 2A charging current is not appropriate. Since 1A discharge current for 4 pcs li-ion batteries will generate a lot heat, and the fan exhausting speed is not fast enough.So it can lead to thermo-protection kicked in, which this safety mechanism is designed for. So I hope it is acceptable. If only two batteries is discharged at 1A speed, it should be no problem.

3. Power spikes from the power supply
We noticed for 9A peak current with very little period time of less than 10ms. we improved this problem by adding a larger enough filtering capacitor and its peak current now is reduced to 7A. The problem is not 100% solved, however it is improving the power supply quality significantly.

4. Uses trickle charging for NiMH when cell is fully charged
I think trickle charging current for nimh is necessary. And we believe this is a good feature of this charger. We have no plan to take this trickle charging away for nimh batteries. For li-ion batteries, there is no trickle charge current.

So are the PowerFocus units for sale at Banggood being shipped with the updated firmware?

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Icon wrote:
Excuse my ignorance on such things, but this says it will discharge, does that mean it will set a charge for storage?

No, the discharge program will discharge li-ion cells fully (to 2.8V, Ni-MH 0.9V).

It is best to store around 3.7V, so you will need to take the cells out, but you can see the voltage as it discharges.

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not yet. the new firmware will show version number 2.0. But I think they will change to new firmware soon because new version has been shipped to them since last week.

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