Is the spike still an issue? I'm not clear on all this. Looks like a great charger other than that issue.
That Powerfocus is too expensive unless it's revised and working properly.
so anyone already arrange a group buy for this charger?
i cannot reach the bogus website powerfocus.net 
This URL has much commercial material about the product?
What does it say, it it the revised version of Chloe's product? :)
Hopefully it’s the fixed one. There is a fixed firmware according to post #127. Google Translate gives me a headache though.
- Joe
I thinks the group buy fir this charger just started:
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
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.
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.
Thank you, Henry!
Excuse my ignorance on such things, but this says it will discharge, does that mean it will set a charge for storage?
So are the PowerFocus units for sale at Banggood being shipped with the updated firmware?
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.
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.
How can you tell what firmware is installed on the unit?
when first power up, before full segment is turned on, it will show 2.0 for 2 second.
HKJ wrote Test/Review of Analyzing NiMH/LiIon Charger Opus BT-C3100
showed …
Charger NiMh.
I asked the seller to OPUS …. “–ΔV where is here?”
Dea”OPUS”: This product is no longer available.
What methods CHARGER stop! working?
–ΔV ???
0ΔV ???
1.45v???
Today I received a response.
===
Whom to believe ?
Manufacturer ?
Or pictures HKJ?
Welcome to BLF, Alexp! :party:
It looks like Henry already explained; it uses both negative delta voltage and zero delta voltage (there are temperature sensors too). It is even recommended to use all three in this PDF dated from 2001:
http://www.le.ac.uk/seis-uk/downloads/Charging%20Nickel%20Metal%20Hydride%20Cells%2030.01.01.pdf
This thread may help. It mainly discusses the Maha C9000 which has similar behaviour (and also uses trickle charge).
Anyway, I just charged some slightly discharged Eneloop AAA at 500mA and they terminate past 1.45V but the current was falling from 1.47V, and trickle charge is <24mA.
Thank you. I know it.
OPUS BT-C3100 uses which method at the end of charge NiMh?
I just OPUS BT-C3100 interested.
In HKJ (# 153) was not seen these methods closure charge .
Im wondering if the C and D adapters for models BM200 and Maha C9000 will fit and work on the BT-C3100??
Anyone knows?
Thx.
I mean this ones:
http://www.aliexpress.com/item/2Pcs-Lot-Battery-Adapter-Charge-Test-C-D-Cells-PowerEx-MH-C9000-Charger-or-BM200-Free/1061338631.html