Review of / Measurement on 4Sevens Single Bay Charger V2

[pblanch]

My appologies to all. I have moved my query to Batteries section.

 

[HKJ]

Oh, I don't know that there's been any violation of etiquette here. JA(me)S question is, at least in part, about the 4Sevens charger. I suppose it would be up to HKJ to determine.

The question was fine for me, but I has been on a weeks vacation with a bad internet connection and not been able to do much posting.

I agree with your answer, 4Sevens looks like a good charger, but we need more time to really know it.

 

[pblanch]

Well received mine today. All bits and pieces present.

Found that something that was rattling around inside the unit. Was a little surprised. I decided not to use the unit in case it was a piece of metal or something. Decided that it would cost more to send back than the unit, so opened it up. Found a 3mm piece of clear plastic in the unit.

Little disappointed that quality control a little lacking. I hope 4 sevens gets onto the manufacturing and informs them no added extra's apart from those listed.

Haven't powered the unit yet and will charge a battery when my battery is a little lower.

Will let you all know.

 

[samgab]

Superb work HKJ. I'm glad there are people like you out there who do all this testing that people like me can benefit from. My 4Sevens single bay V2 arrived in the mail today, and I've put it into commission immediately. This must be one of the most affordable consumer "bay" chargers that uses the correct CC/CV method?

 

[nobunaga88]

Hello,
I just wondering what should i set for my AW 18650 2900mah?
let me say i set it for 1A, then for the best Voltages is it on 3.6V or 4.2V??
what is big deal if i set on 4.2V? is it gonna blow?

Sorry for my Totally noob question...and for my english...

Thanks Guys :naughty:

 

[HKJ]

Hello,
I just wondering what should i set for my AW 18650 2900mah?
let me say i set it for 1A, then for the best Voltages is it on 3.6V or 4.2V??
what is big deal if i set on 4.2V? is it gonna blow?

Sorry for my Totally noob question...and for my english...

Thanks Guys :naughty:

These batteries (like most LiIon we use here) are ICR or LiCoO2 cells, i.e. you must use 4.2 volt. Using 3.6 volt would not damage the cell, but you would not get any charge in it either. If you charger a 3.6 volt cell on 4.2 volt you might get trouble!

All 18650 batteries can be charger on the 1A setting, the 0.5A setting is for smaller batteries. You can see my table "Supported battery sizes" for some recommendations on current switch setting vs. cell size.

 

[nobunaga88]

These batteries (like most LiIon we use here) are ICR or LiCoO2 cells, i.e. you must use 4.2 volt. Using 3.6 volt would not damage the cell, but you would not get any charge in it either. If you charger a 3.6 volt cell on 4.2 volt you might get trouble!

All 18650 batteries can be charger on the 1A setting, the 0.5A setting is for smaller batteries. You can see my table "Supported battery sizes" for some recommendations on current switch setting vs. cell size.

Thanks HKJ for your Fast reply

anyway,
i got an email from Ryan from Going****.com, that if i want to match the voltage. So charge the 18650 on 3.6V (On this 47 Charger V2)

in that case, i must charge on 3.6V?
Then you say that i must charge my AW 2900Mah on 4.2V?

i'm Little bit confused here (maybe because my english very poor)
Maybe i Need 2nd Opinion here

Greatly Thanks
Kindly Regards

 

[samgab]

You are confused by two different things.
3.6V is the nominal voltage, but you have to charge it at 4.2V.
Have a look at the data sheet for the cell you're asking about.
The answer, as HKJ said, is set it to 4.2V for the AW2900.

 

[Stephen Wallace]

As stated, you will see that LiCo and LiMn cells are marked as having a 'nominal' voltage of 3.6 or 3.7v. Broadly speaking, this refers to a midway point in the cells voltage between being fully charged and discharged. The voltage of the cell is highest when freshly charged, and as the energy in the cell is depleted, the voltage will drop. So, the fully charged voltage will be higher than the nominal voltage.

The nominal voltage is also round about the voltage that the cell will return to after discharging it, once the load is removed. So for instance, you start with a charged battery, discharge at 1A, and when the cell voltage *under that 1A load* drops to 3v, the discharge is terminated. Without the 1A current draw, the voltage will rise again, despite the fact that the battery is for all intents and purposes drained. If you then installed that cell in a charger set to 3.6v, then the charger would sense that the battery already read at 3.6v, and so would think that the battery were fully charged even though it wasn't. The 3.6v setting is for LiFe cells, which have as lower nominal voltage (normally stated as 3.2v if memory serves), which rises to 3.6v when fully charged.

As both HKJ and samgab have stated, LiCo and LiMn cells have a nominal voltage of 3.6 or 3.7v, but this increases to 4.2v when fully charged, so you need to use the 4.2v setting on the charger.

 

[nobunaga88]

i see,,
Now i do really understand...

Thanks HKJ,Samgab, and Stephen :wave: for enlightment :twothumbs

I Hope 4sevens charger coming soon on dual bay

 

[Rexlion]

I just received my 4Sevens charger and tried it out. Charged 4 IMR 26650 cells from Lighthound and they all terminated at 4.20v or 4.19v. Then I switched the charger to .5A and put in an AW IMR 16340, and it finished at 4.16v. I'm happy with it.

Thanks for the review HKJ!

Edit: This a.m. an older (gray) Trustfire 16340 charged for a while and then the charger began blinking, alternating between red and green lights! Checked the cell, it's at 4.05v. The cell might be getting too old to accept a full charge. But I don't recall seeing any reference to flashing lights anywhere about this charger, so I thought I'd bring it up.

 

[tony22]

HKJ (and 45/70) what's your sense of the pros and cons of this charger vs. the XTAR MP2? Not counting that the MP2 can do 2 batteries of course.

 

[HKJ]

HKJ (and 45/70) what's your sense of the pros and cons of this charger vs. the XTAR MP2? Not counting that the MP2 can do 2 batteries of course.

It does follow a true CC/CV charge profile, making it the fastest charger (But only with one battery at a time), but sadly it terminates charging before the battery is full (This is mostly a problem with small cells). If you plan on getting any light with 26650 cells, the 4Sevens also has the advantage, it can directly fit the cell, you do not need to make some sort of connection from charger to battery. The placement and marking of the switch is also much better on the 4Sevens charger. The support for LiFePO4 batteries may also matter to some people.

 

[tony22]

Thanks. Which one would be a better solution for a proper charging of RCR123?

 

[HKJ]

Thanks. Which one would be a better solution for a proper charging of RCR123?

For 16340 (RCR123) I would use the WP2 V2, due to its lower termination current.

 

[tony22]

Okay. I found a U.S. based seller on eBay with perfect Feedback so I just picked one up.

 

[45/70]

Thanks. Which one would be a better solution for a proper charging of RCR123?

Although it has not been around very long and is basically as of yet, unproven, as it stands now, I would pick the 4Sevens charger, regardless of the termination current.

The XTAR just has too many "quirks" for my taste. The XTAR chargers are improving, and are probably better than most "consumer type" Li-Ion chargers out there, but IMO, they still "ain't quite right". They appear to use many "shortcuts" to achieve a charger that "almost" qualifies as a proper charger. Maybe someday......

Dave

 

[tony22]

Well, I like the idea of being able to do two batteries at once so I'm going to give the XTAR a try. I was also just a little concerned about the data seeming to indicate the 4sevens didn't quite get the battery up to it's full specified voltage (I guess because of the higher termination current?). Why can't anyone get one of these things right?

 

[Acid87]

Sold. I've always been a bit wary/lazy with Li ion cells this makes it easier so think I'll maybe pop on one. Only downside by the sounds is the charging of RCR123s.

Cheers for the review HKJ as usual

 

[45/70]

Why can't anyone get one of these things right?

Heh, I've been asking this question for years. The only proper "consumer type" chargers that have come about so far, are the Pila IBC, and it looks like the 4Sevens. Neither one of them are perfect, but are very close.

A few years ago I was told by those with more expertise in electronics than I, that it would actually be easy and not cost all that much to make a charger that worked as the Li-Ion cell manufacturers recommend. I had originally suggested that it might be more expensive to make one, but they all said no, it wouldn't. Now they are suggesting that a charger that charges cells using the proper algorithm would be too cumbersome and expensive. So anyway, I'm not sure which is correct, but I would prefer a charger that charges cells properly, regardless of the cost.

I think you'll be fine with the XTAR. As I mentioned before though, it (they) just has too many "quirks" for me. I think the cost cutting measures must have something to do with this. It seems though that if you did away with the whole voltage checking thing, which is not part of a proper charging algorithm, nor even necessary, that you could come up with a charger that actually worked correctly, for the same cost. Then again, maybe not.....:shrug:

Dave