Xtar WP6 II questions

[inquisitorj]

All the talk of battery safety lately got me back into the habit of metering my batts as they came off the charger. I noticed that my old trusty Trustfire TR-001 is charging my batts up to 4.25V. Now unless I am mistaken that is too high. I decided that it was time for an upgrade, so I did a little research and settled on the xtar MP6 II. For the price, the features seemed unbeatable.

I got it today and put in one of my AW IMR 18650 2000mAh that I had purchased recently from SuperT. Just to check, the starting voltage on the cell was 3.7V. I know it didn't really need to be charged yet, but it wont hurt to charge it early and it was my only cell that needed charging. As soon as it went green, I pulled out the cell to check end voltage and it is reading 4.28V! WTF!?! I checked it again 20 min later and it was still reading 4.28V.

What is the max safe voltage that a cell should be charged to keeping cell longevity in mind? I thought it should be closer to 4.2v.

Is 4.28V standard for the xtar? Am I just being too picky?

The way I understand it is that 4.3v and above is dangerous where above 4.2V and below 4.3V reduced the life span of the cell. Please let me know if I am wrong here.

 

[retird]

What is the specifications for your multimeter? Most have a +/- variance. May not be the charger, may just be the reading on your meter...just a thought...

here is a spec for a multimerer I looked at:

Accuracy (DC) +/- 5% of scale, resistance +/- 5% of Ffll scale

 

[forcedfuel50]

It actually varies by battery type and brand too (regardless of charger brand). Even in the same charger you'll see the IMR's charge to a different voltage then say your AW Protected batteries. Most chargers i sell have a spec of 4.2 +/- 1 or 2 percent max. I'll test a few for you if you'd like on one of my Xtars, i've never checked their voltage coming off that charger.

 

[inquisitorj]

It is a cheap meter. It is one of those $10 Harbor Freight Cen-Tech meters. Can't afford a good meter right now, but if there is a decent one at a good price, I may be able to afford it.

 

[okcodemonkey]

Looking forward to the answer to this one. I just got done eyeballing that exact same charger.

 

[inquisitorj]

I would appreciate it. Is charging to 4.28V safe for an AW IMR 18650 2000mAh cell?

 

[mwa102464]

Quote = inquisitorj
The way I understand it is that 4.3v and above is dangerous where above 4.2V and below 4.3V reduced the life span of the cell. Please let me know if I am wrong here.



I would agree with this, they are made to charge to 4.2x not above and shouldn't be charged above from everything I know about them and have read from the specs.

 

[retird]

From lighthound.com (imr 18650 1600mah):

Attention : These IMR cells have much lower internal resistance than regular LiIon 3.7V cells and they may end up with a higher ending voltage when charged in certain chargers ( especially older version WF-139 charger ). Please check the voltage of them right out of the charger to see if they are above 4.20V when fully charged with your charger. Overcharging above 4.25V may shorten life/cycles. Above 4.50V may even pop them or making them leak. DO NOT use the charger if it seems to overcharge IMR cells.

 

[retird]

And from another vendor's site:

AW IMR18650 2000mAh Battery Specifications:
Nominal Voltage : 3.7V
Capacity : 2000mAH
Lowest Discharge Voltage : 2.50V
Standard Charge : CC/CV ( max. charging rate 2A )
Cycle Life : > 500 cycles
Max. continuous discharge rate : 10A
Operating Discharge Temperature : -10 - 60 Degree Celsius

NOTE:These IMR cells have much lower internal resistance than regular LiIon 3.7V cells and they may end up with a higher ending voltage when charged in certain chargers ( especially older versions of the WF-139 charger ). Please check the voltage of your 18650 IMR battery right out of the charger to see if they are above 4.20V when fully charged with your charger. You can do this with a Multimeter Overcharging above 4.25V may shorten life/cycles. Above 4.50V may even damage them. DO NOT use the charger if it is overcharging IMR cells.

Other Caution Notes:
- Do not over-discharge/overcharge
- Recharge empty batteries ( resting voltage ~3.6V ) as soon as possible. Leaving Li-Ion batteries in discharged state will incur irreversible damage ( capacity / cycle loss )
- Do not short circuit ( will release tremendous current )
- Do not dispose of in fire.
We do not recommend unprotected batteries, use at your own risk. If used in our devices using our Hot Spring, if there is a short the spring will collapse. Do not Use adapters with these batteries.

 

[forcedfuel50]

If one wants it to go only to 4.19 approximately, then i'd recommend the PILA. All the WF 188, Tr001, WF138A,B, XTARS, WF139, etc all spec at 4.2 +/-1% so you'll see them on either side of 4.2, its the reality of the more inexpensive chinese chargers. I wish we had the ability to make our own brand of chargers in house

That being said, 4.28 seems on the high side when the specs are 4.2 +/- 1%, so i can test that out and exchange it for you.

 

[Riverboat]

If one wants it to go only to 4.19 approximately, then i'd recommend the PILA. All the WF 188, Tr001, WF138A,B, XTARS, WF139, etc all spec at 4.2 +/-1% so you'll see them on either side of 4.2, its the reality of the more inexpensive chinese chargers. I wish we had the ability to make our own brand of chargers in house

That being said, 4.28 seems on the high side when the specs are 4.2 +/- 1%, so i can test that out and exchange it for you.

Got to agree with David.. I bought a Pila from SuperT about a year ago when he first started carrying them...... Its the best charger I have ever owned. Batteries allways come off at 4.19---4.2 volts. Even AW IMRs............

 

[inquisitorj]

It must be a resistance thing. My AW ICR 123/16340 3.7v batts charge up to 4.22V I do need 4 spacers each, but they ohmed out at maybe a tenth of an ohm if any.

 

[inquisitorj]

Maybe it is time to just bite the bullet and invest in the Pila.

 

[inquisitorj]

I just took off a couple of AW IMR 18350s and got voltages of 4.23V and 4.24v respectively. I guess the little bit of resistance in the spacers to enough to keep the max charge to a lower/safer level. I am going to try using a dime spacer for the next AW IMR 18650 that I charge and see what that nets for me.

 

[inquisitorj]

Well the dime helped a little bit. Ending voltage was 4.26v instead of 4.28V

 

[Riverboat]

Maybe it is time to just bite the bullet and invest in the Pila.

Pila all the way...........

 

[inquisitorj]

I received my replacement charger, and it is charging to spec. My initial charger was just defective.

 

[matrixxu]

Makes sense, the Xtar chargers seem to be the next best thing after Pila ones, so i was a bit surprised to read about 4.28 end-voltage.

 

[snork]

I just received my AW IMR 26500s I bought in anticipation of the Shockwave. My, that's a big battery! It fits in my WP6 II just fine, with two spacers.

 

[BuzzKilla]

OR the guys at Super-T can start carrying hobby grade chargers....


they can be had for cheaper than the Pila but are infinitely better.

just sayin'