POLL: Your favorite Chinese knife?

That depends on the actual battery, then 1C charge rate is rule of thumb, not a specification or a law.

IMO, damage at 1c will be minimal, it would be interesting to see cycles compared between 0.5 & 1c.
Above this damage will get progressively worse, ie on the 4200mAh, 4.3 amps would be so close to 1c I doubt a difference would be noticed

Right, I figured it was somewhat standard for the chemistry and based on that? But I guess there is no telling with the Chinese cells what is inside as to chemical composition and how they really stand up unless you tried it.

Not only Chinese cells, the Panasonic 2900 and 3100mAh cells are 0.3C charge current. The new 3400mAh cell has been upgraded to 0.5C.

Thanks HKJ for your valuable input, your technical view is as always highly appreciated.

Since you like the 2A, i have voted for 2.0A now too!

:p

PFC = installing more capacitors? If so I can see how it would cost more.

That is not enough today, a full compensation requires an activate circuit that will regulate the current draw.

Here is some more explanation (It is technical): http://www.fairchildsemi.com/an/AN/AN-42047.pdf

my PC power supply, engineered in Gemany, has it.

active PFC:

kreisl wins :p

It would be illegal in the entire EU, if the PFC was missing or you would have a very low power PC.

So what would you think about an integrated power supply (no power adapter!) in a dream charger with 4×3.0A output, say ~50-60Watts. Should it have active PFC too? :)

As I wrote above, I do not know exactly where the limit is today.

No stick to normal external PSU Dinoboy. The ability to run off of 12v battery bank is useful and also failure of PSU doesn’t mean scrap charger also :cowboy_hat_face:

Oh, 12V input is kinda standard with most modern chargers. Nitecore i4 was exceptional with both 12V input and built in power supply unit.

Right now i am charging 2x18650 in the Nitecore i4 starting off 3.80V (slot1 and slot4 occupied) and the back of the charger is really hot by now. Maybe the heat production has something to do with the built-in PSU? Output is only 2x0.75A (nominal) but wtf does the charger get so hot?

The two 18650's are slightly warm, nothing to be concerned about, i guess.

It's time for a new, better built charger. The dream charger.

Do you have any other mains leads you can use instead, or a 12V power supply?

BatterySpace.com/AA Portable Power Corp. Tel: 510-525-2328 - Powerizer Battery Official Site These are high drain with 1500 cycle repeatability. Made for cars and scooters. I’m using them for my HD2010. 18A constant draw rate at 3000mAh capacity. $9.50 ea.”

These are listed with a charge rate of 1C…so we do have one confirmed that could easily take a 3A charge rate. I know 1C is a guideline, 26650’s are the only reason I say 3A charge rate at least for the 4-6 channel dream charger :slight_smile:

that's a tricky question i think! ;)

Yes another advantage to external power supply is heat generated in the rectifier will not be conducted to the cells. Possibly a much bigger problem for a NiMh charger as it may monitor the temperature delta, as all good chargers do, to terminate correctly.

on the one hand I believe that temperature delta is the correct classic way to terminate charging. on the other hand modern dream chargers have a full-fledged big CPU inside, quite similar to PC CPU's, and one could program the CPU to simply monitor the exact voltage and then terminate the charging when the target voltage, e.g. 1.470V has been reached. So the CPU controls the charging process directly through the actual voltage instead of monitoring the classic temperature delta.

Was a hot long day today, if i am talking **i* lemme know and i'll try to cut the ***p ;)

Temperature would not be the primary termination method, usually voltage as you say (although delta V looks for a slight dip in voltage at correct termination, it’s applying CC). The temperature is a back-up method but still this fails, at least I’ve seen reports of chargers missing termination.

Excellent point. This heat conduction problem was observed in some less popular Chinese C9000-like charger by Opus Instrument Co., Ltd, the inexpensive BM210 charger now marketed by the Danish Japcell brand:

http://www.amazon.com/review/RRZI4G772IAVR
http://www.amazon.com/review/R30IYBU06GPMKC

XTAR designers and engineers need pay special attention to the efficient removal of heat into the right direction. Not into the cells!