New XTAR WP2 II Li-ion charger

Lightfoot98

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I recieved the WP2-II a few days ago and ran several cells thru it to check function and to determine cut-off voltage.
It consistently charged to 4.20 and held it there in CV untill cut-off. That is on both bays.
Checked at 500ma and 1000ma.
All my cells came hot off the charger at 4.18 as soon as charger terminated.

Mine came with 2 spacers.

I really like this charger.
 
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tony22

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Well, now I'm confused. I just got mine and it looks like I got no spacers - but I did get the 12V adapter! Is it obvious in the WP2 box where the spacers are located?

If I really didn't get them, what spacers do I need to buy for RCR123 batteries?
 

tony22

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Can someone post a pic of what the supplied spacers look like? I'd like to email that to the retailer where I got mine to see if he could track them down. Given the iffy nature of actually getting them in the package I'm not sure I want to risk a return in the hopes the next one will have them.
 

scottyhazzard

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Thanks 45/70. I can't afford a fire.

I will try posting photos of my Xtar from SBFlashlights.

Spacers in... Spacers are at top of battery bays-
Xtarspacers.jpg


Spacers out...
Xtarnospacer.jpg


I hope this helps, tony22
 
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tony22

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FYI the seller confirmed that the earlier batch (1 month old!) did not have the spacers but the recent batch he received did. He said he would take care of things by sending one out.
 

tony22

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I should have my spacers by tomorrow. It hadn't occurred to me until now to ask about the best way to get my new RCRs going. Since the WP2 II doesn't seem to do any sort of fancy discharge-charge routine, is it better to use the new cells until they run down, or top them off on the charger before first use?
 

45/70

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......It hadn't occurred to me until now to ask about the best way to get my new RCRs going. Since the WP2 II doesn't seem to do any sort of fancy discharge-charge routine, is it better to use the new cells until they run down, or top them off on the charger before first use?

Hi Tony. The only time you would charge/discharge Li-Ion cells, is when you want to check their capacity. Otherwise, there is no benefit to doing this to Li-Ion cells, it just wears them out.

As for your new cells, I would charge them up first. Unlike other types of cells, Li-Ions prefer shallow, rather than deep discharges. Avoiding deep discharging your cells can extend cycle life considerably.

Another difference between Li-Ions and other types of cells, is there is no drawback to "topping off" cells often. The only time you might want to avoid doing this, is when you are not going to use the cell(s) for a while. In this case, it's best if you store cells at about a 40% state of charge level. This prevents the more rapid internal degradation that occurs when cells are at or near maximum charge level, and at the same time, prevents any possibility of the cell self discharging to a damaging low voltage, if for example, you were to end up storing them longer than planned.

Dave
 

tony22

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Got my spacers (does the charger come with only two?). Charged my first RCR123 and pulled it when the light turned green. I'm not sure if I should be a little disappointed. The voltage from my Fluke DMM read 4.15 volts. That seems a bit low if a RCR is supposed to come in at 4.20. Or is it?

I used the 500 mA setting.

Hmm, I put the nubbins on the other charging space and popped the batteries in there. It went red then after a short while green. I got 4.17 volts there. Is that more because of a bit of "rebound" charging or is it possible the second space charges it up a bit more?
 
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Mr Happy

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Or is it?
No, not so. If a battery came off the charger at 4.20 V the charger would not be working properly. The only way to get a battery up to 4.20 V without waiting forever is to raise the charging voltage above 4.20 V, which the charger is not supposed to do.
 

tony22

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No, not so. If a battery came off the charger at 4.20 V the charger would not be working properly. The only way to get a battery up to 4.20 V without waiting forever is to raise the charging voltage above 4.20 V, which the charger is not supposed to do.

Ah. So what's the minimum acceptable voltage for a properly charged RCR123?
 

45/70

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Tony, keep in mind that a LiCo cell with an OC voltage of 4.15 Volts translates to roughly a 95% charge. Also keep in mind that 4.20 Volts is the maximum allowable voltage for LiCo and LiMn cells. However, this figure is actually stated as 4.20 Volts +/- 0.05 Volt (or +/- 1%), so either way, your cell is in spec.

Cells charged at a higher rate (in proportion to the cell's capacity) will not charge as fully as cells charged at a lower rate. This is why an 18650 cell will normally come off the charger at a higher voltage than a 16340 cell, when charged at the same current rate. This assumes that the two cells are of the same type, age, and condition. The older, or more used a Li-Ion cell is, the lower the charged voltage will be.

This voltage variance is common, when using a charger that utilizes a proper CC/CV charging algorithm, which the XTAR imitates fairly closely. Many cheapo chargers will actually always charge cells of different sizes, ages, and capacities to the same voltage. These chargers damage the cells in the process, as they are actually overcharging the cells.

Dave
 

jasonck08

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No, not so. If a battery came off the charger at 4.20 V the charger would not be working properly. The only way to get a battery up to 4.20 V without waiting forever is to raise the charging voltage above 4.20 V, which the charger is not supposed to do.

The final charge voltage has to do a lot with the termination current. For example a 100mA termination current may leave the cell at 4.15v, while a 50mA termination might terminate at 4.18v.
 

FreeMagenta

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Hello I am charging TF 2400 "Flames" in my WP2, and with each cycle the after cutoff voltage goes higher. Just now, it looks like this: http://www.youtube.com/watch?v=wtJaMhcahNo (Cutoff about 4:50)
Battery voltage just after cutoff 4,19, drops to 4,18 in 2-3 minutes and stays there for 6 hours. First cycles were about 4.15... I am measuring the battery voltage after each charging, and it always goes by few milivolts up. From 4.15 top 4.19V with each cycle.
Shall I be worried?...
 

tony22

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Hello I am charging TF 2400 "Flames" in my WP2, and with each cycle the after cutoff voltage goes higher. Just now, it looks like this: http://www.youtube.com/watch?v=wtJaMhcahNo (Cutoff about 4:50)
Battery voltage just after cutoff 4,19, drops to 4,18 in 2-3 minutes and stays there for 6 hours. First cycles were about 4.15... I am measuring the battery voltage after each charging, and it always goes by few milivolts up. From 4.15 top 4.19V with each cycle.
Shall I be worried?...

FreeMagenta, are you letting the battery discharge before cycling it again?
 
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