Review: Ultrafire 3600mAh protected 18650

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Stephen Wallace
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Review: Ultrafire 3600mAh protected 18650
 
 
Time for another quick test of a single cell provided for testing by Jim - UK Ebay member big_f_d_d.

Jim does not have this cell listed on his ebay page, so will not profit from this review, be it good or bad. So, I'm just going to set out the facts with no favouritism, and no massaging of the figures. Whatever values I measure, I'll post here.

This will be a test of the cell’s overall capacity, as measured with a 0.2C discharge, and then seeing how capacity alters as discharge rates increase – is capacity maintained well, or does the voltage sag and lead to the cell not delivering it’s stored energy before the minimum discharge voltage is reached.

With my review of the Ultrafire 3000mAh cell, I expressed that I had an interest in testing the cell, as I had previously owned two of them, and wanted to see how a new one compared to two older, used cells. As it is, it compared badly. With this 3600mAh cell, any curiosity I had was entirely of the morbid variety.....

Fact is that we all know that there is no currently commercially available cell with a 3600mAh capacity. The stated capacity of this cell is quite simply an out and out lie. The real question here is, is this actually a decent enough cell, but with an exaggerated capacity - like the Trustfire 3000mAh; or is the fake capacity an excuse to put any old cell under that bright wrapper. If we know for a fact that the cell isn't what it claims to be, who knows what it might actually be.

I'm going to cut right to the chase here, and say that it's the latter. Capacity is very low. Voltage sag was surprisingly low up to a 2C discharge rate, but that's about as positive as it gets.

Testing Equipment

As I have stated in all my reviews, I try to carry out all my charging on one charger, an iCharger 106B+, and carry out the discharges and internal resistance tests on a second charger – an iCharger 208B. The idea is to be charging one battery while discharging another, in order to speed up the workflow, but to always use the same charger for the same steps, to ensure that results are directly comparable.

Voltage is measured with a Precision Gold WG 020 multi-meter, dimensions with a Precision Gold digital calliper, and weight with a Neva digital scale stated to be accurate to 1/100th of a gram.

The base of the cell is attached to the charger via a 12” 16AWG cable with a large, strong magnet soldered to it. The positive button is attached via a magnet (if it adheres well) or via a crocodile clip. In this case, the magnets adhered well at both ends. Where it has been hard to get a good contact, and so internal resistance has been high, I have sometimes resorted to feeding a split ring or paperclip through the cell's vent holes to give the croc-clip something that it can grips securely. I had to resort to this technique with the UF 3600mAh to minimise IR.

Results at a glance

Ultrafire 18650 3600mAh protected

Provided for testing by Ebay UK member ‘big_f_d_d’

Big_f_d_d does not currently have this cell listed on his ebay page, so I cannot comment on pricing, but it is freely available from other ebay dealers, or the common China/HK electronics retailers – for instance, KD, DX, DD, BIO, BOB, Manafont, et al are likely to stock these.
 

 

Cell 1 (1)

Initial voltage on receipt

 3.33V

Measured length

 68.70mm

Measured width (max)

 18.40mm

Weight

 43.73grams

Internal resistance at initial voltage

 172mOhm

Capacity from initial voltage down to 3.00V @ 0.7A

 5mAh

Internal resistance after storage charge

 178mOhm

Capacity from 4.2V down to 3V @ 0.7A

 775mAh

Capacity from 4.2V down to 3V @ 1.0A

 779mAh

Capacity from 4.2V down to 3V @ 1.5A

 751mAh

Capacity from 4.2V down to 3V @ 3.0A

 N/A

Capacity from 4.2V down to 3V @ 5.0A

 N/A


(1) This is a single cell provided to me for testing, rather than a purchase that I have made – these cells are normally supplied in pairs.

Although the cell started at quite a low voltage of 3.33V, the fact that only 5mAh was discharged before the cell dropped to 3.00V, didn't bode well. Internal resistance was quite high. though a good deal lower than the 3000mAh Ultrafire I tested. While the capacity was higher from a full charge, it was still low. The only upside was that from 0.7A through to 1.5A, capacity didn't actually drop that much. I didn't risk going beyond an approximately 2C discharge rate. The fact remains though that while voltage sag didn't appear to be much of an issue, you are starting with such a low capacity to begin with, that this cell just isn't worth considering.
 
 
 
 
Ignore the marks around the button - the cell did not have these as received. They are the result of attaching the split pin I use to attach the charging lead.
 

Construction
 
The cell has a medium sized button, but flatter than that of the 3000mAh cell. I’m not entirely certain if the button is steel or aluminium. A magnet will adhere to the button fairly securely, but this may be due to the underlying cell. The magnet is more attracted to the cell shoulder than to the button.

The wrap is fairly thin, but not excessively brittle.

You have a foil style base, which is more likely to experience wear and tear than a solid metal base. As with many newer Ultrafire cells, the foil has the brand name printed on it. This inscription can act as an insulator – for instance, if you had the needle point of a multi-meter in direct contact with the text. However, with the width of a coil spring or sprung plunger in the tail of a light, you should be able to make good contact.

Light compatibility
 

Light

Characteristics

Fits

Functions

Olight M20

Wide tube, spring at head, sprung plunger at tail cap

Yes

Yes

SWM T20CS

Short tube, dual springs

Yes

Yes

Jet IIIM

Wide tube, tail spring only

Yes

Yes

Fenix TK15

Two-piece tube – narrow at head

Short tube, short spring at head

Yes

Yes

Fenix TK11

Narrow tube, tail spring only

Yes

Yes

Eagletac G25C2

Wide tube, sprung plunger at head and tail (minimal travel at the head end), physical reverse polarity protection

Yes

Yes

Nitecore IFE2

Narrow tube, physical reverse

Polarity protection

Yes

Yes


Charger compatibility
 

Charger

Fits

Functions

4Sevens single bay

Yes

Yes

Trustfire TR-001

Yes - just

Yes

Ultrafire WF-139

No (2)

Yes (2)

Ultrafire WF-188

Yes

Yes

HXY-042V2000A

Yes

Yes

XTAR WP2 II

Yes - snug

Yes

Pila IBC

Yes

Yes

Jetbeam/Sysmax Intellicharge i4

Yes - Just

Yes


(2) While the cell is too long to sit all the way down in the cradle of the WF-139 charger, with the cell sat in the bay at an angle, the positive button on the cell makes contact with the charger’s positive terminal, and charging will commence.
 
Internal resistance
 

Cell

Voltage

Internal resistance

Ultrafire 3600mAh

3.33V (as received)

172mOhm

Ultrafire 3600mAh

3.72V (storage charge)

178mOhm

Ultrafire 3000mAh

3.93V (as received)

248mOhm

Ultrafire 3000mAh

3.74V (storage charge)

288mOhm

Trustfire 3000mAh

4.00V (as received)

123mOhm

Trustfire 3000mAh

3.74V (storage charge)

135mOhm

Ridbatt 2600mAh #1

3.74V (storage charge)

129mOhm

Ridbatt 2600mAh #1

3.74V after initial capacity test (storage charge)

135mOhm

Ridbatt 2600mAh #1

3.74V after all testing complete (storage charge)

117mOhm

Xtar 2600mAh #1

3.85V (as received)

139mOhm

Xtar 2600mAh #2

3.79V (as received)

136mOhm

Keeppower 2600mAh #1

3.78V (as received)

123mOhm

Keeppower 2600mAh #2

3.78V (as received)

119mOhm

Hi-Max 2600mAh #1

3.79V (as received)

153mOhm

Hi-Max 2600mAh #2

3.80V (as received)

163mOhm


I have compared the Ultrafire 3600mAh with the similarly exaggerated 3000mAh cells from Ultrafire themselves, and from Trustfire. As the Trustfire 3000mAh cell was found to actually be in the same capacity range as 2600/2500mAh cells, I have bulked out the rest of the internal resistance table with cells listed as having a capacity of 2600mAh, which seems more in line with the true capacity of the Trustfire. We’ll see how the Ultrafire compares.
 
Edited by: sb56637 on 08/26/2014 - 17:46
Stephen Wallace
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Conclusion

I wouldn't personally recommend this cell. The stated capacity is obviously bogus, and the genuine capacity is very low. While the cell will actually support a 2C discharge, that only works out as a little over 1.5A, so only good for XR-Es, XP-Es and XP-Gs.

If you are looking at buying cheap "firebrand" cells, do yourself a favour, and buy the Trustfire 3000mAh cells. They also have exaggerated capacities, but nothing like as bad as the Ultrafire. They have over three times the capacity, and will happily support a 5A discharge without a great deal of capacity loss.

dorpmuller
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Ask me why I stick with AW's...

"I am the flashlight king! I can light anything!"

turboBB
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Thx for the review!!

Trancersteve
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Thanks for the review.

I'll avoid this one!

I wear my sunglasses at night.

how2
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Can you do a pro and cons for all of your battery reviews please. Sometimes I just want the fact fast. Thank you

Stephen Wallace
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Once I have a few more tests completed - specifically, more tests of cells of similar specifications - then I can start making direct comparisons between cells and say which are best, rather than just broadly stating whether something appears good or bad. 

ri chevy
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how2 wrote:

Can you do a pro and cons for all of your battery reviews please. Sometimes I just want the fact fast. Thank you

X2.  Thank you!

JohnnyMac
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Great info.  Thanks!

BetweenRides
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Thanks for another great review. You are saving a lot of users from investing in... Crap.

Much appreciated!

dthrckt
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holy crap-oly

I'm betting there is a recycled/used cell inside that wrap

Burro
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Thanks for your time doing these tests, as already said this is the reason if use only AW cells, in fact I have two AW's approximately 4 years old that still test very close to there rated capacity. 

 

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