POLL: Your favorite Chinese knife?

+1

:stuck_out_tongue:

I’m surprised 1.5a seems quite common on a 26650 or even 32650 charger. Votes seem to dictate at least 26650.

I haven’t read up on Li-ion charging but is it similar to some other chemistries in that a middle current can be a bad choice as termination is hard to identify for the charger and thus overcharge is very possible?

A really low that is safe long term works I guess but at levels that low you are looking at 12hr+ charging time (and who wants to sleep with the charger on!)

A relatively high charge rate that the manufactures say a cell will safely accept is best to aid termination and keep times realistic.
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Edit;

Infact DigiKey specify a 1c charge rate, so a 26650 ideally around 4A!

Source: http://www.digikey.com/us/en/techzone/power/resources/articles/a-designer-guide-lithium-battery-charging.html

I'm with Texaspyro, none of the choices have high enough numbers

i am not the only one who masters the art of stealth deletion, thanks ezarc :p

i haven't voted yet. still undecided. i think the hardcore charging people incl HKJ prefer 3.0A?

No, 2A for a slot is enough. With 18650 I nearly always uses 1A. With 26650 the 2A current is fine for standard charge, many of the 26650 batteries could accept 3A or 4A for a quick charger (i.e. with slight damage to the battery), but I have not seen a need for that.

Making higher charge current in a charger will also make it more expensive, especially if you need PFC correction (Required at higher power levels).

Are you required to have PFC over a certain power in Denmark? I’d be surprised if even a 4a, 4 channel charger required one. Would be nice tho.

I agree 2a is enough but more would be nice, who knows what’s around the corner and the ability to rapid charge if really needed would be nice.

Yes, it is above a certain power level, the rules are common for EU.

I do not know exactly at what power, probably somewhere between 60 watt and 100 watt. A 4A 4 channel charger might be around the limit.

What is around the corner, might required other voltages. I prefer to charge at safe current levels and then more batteries at the time.

That’s how I thought about it too, plus I know the 2A ~ .5C is better for the battery but 3A is under 1C and should be able to accept that charge …shouldnt really damage a 4200mAh 26650 battery until 4.3A should it?

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.