4000mah protected 18650

[chipdouglas]

I didn't find anything in the search. And i havent read about them here. but i came across a page that sells

4000mah protected 18650's

2PCS 3.7V 4000mAh 18650 Protected Li-ion Rechargeable Battery


before i order some, i want to see if anybody has experience with these. if not the i will get them and do a review.

michael.

 

[Astralist]

ultrafire never release a 4000mAh protected 18650's
look at official website of ultrafire.
here: WhaFat Technological Co.,Ltd

i have tested a 3600mAh type, but it's worst than 3000mAh type.
i also have read at some flashlight forum that someone there tested a 3600mAh version, and it has an internal resistance and that it's bad.
maybe 4000mAh version is the same bad as 3600 type, but since it's cheap, maybe there's no problem to test it

FYI: it's very easy to duplicate something in china (especially in shenzhen city), so you should trust only from official website. in their official websites, the max capacity for 18650 are 3000mAh (red plastic cover)

 

[chipdouglas]

i didn't think the chinese would rip each other off. i though there was honor among thieves lol. ( i don't mean chinese as people, but chinese companies that copy international ideas)

michael.

 

[BShanahan14rulz]

no such thing as a 4000mAh 18650 lithium secondary

 

[Coherent Light]

Oder a pair and do a review please. I am betting They only put out ~2600mah.

 

[LarryDFW]

michael;

The top rated manufacturers in the world of #18650 cells only have ~3000mah of capacity.

Chinese cells are usually well under this capacity.

More importantly, the operating life is much less.

Larry

 

[Coherent Light]

LarryDFW do the name brand batteries perform better after 2 or 3 Cycles like the cheapie Chinese ones seem to do?

 

[Benm]

michael;

The top rated manufacturers in the world of #18650 cells only have ~3000mah of capacity.

Chinese cells are usually well under this capacity.

More importantly, the operating life is much less.

Larry

I'd agree on this. Even top of the market laptop batteries that use 18650 cells use only 3000 mAh per cell, and money is little concern there. At this time i would say that circa 2500 mAh real capacity is normal, good quality, and something close to 3000 mAh would be state of the art.

As for thieves scamming thieves... don't be too surprised. A brand like ultrafire has built a reasonable reputation so far, and i would not hold it beyond possible that some unrelated factory preys on their brand name. I'd stick to plain old grey ultrafires that DX sells - they arent the best batteries in the world, but good value for money and not too far from the rated 2400 mAh.

 

[chipdouglas]

thanks guys for all the input. i will not buy these.


michael.

 

[Illuminum3415]

People tend to believe whatever the label says, and that they unconditionally assume all companies domestic or international always act with good faith and would back their products even if you threaten to shoot the production manager on the shop floor. However, under the dotrine of caveat emptor they know good and well they can get away with anything. Even with the most reputable companies, learn to derate values [not just because your house isn't TA = 25C and your room isn't being fed by an air handler that uses H11 HEPA Air Purifiers]. It'll save you alot of trouble, frustration, and perhaps reward you with an unexpected bit of extra runtime

Capacity can be increased slightly by decreasing the rate of discharge... supposedly saft's line of Lithium-thionyl chloride (Li-SOCl2) cells took advantage of this. I'm already suspcious of 3000mah 18650s, for all calculations I still use "2200mah" for 18650. While it has not failed me yet, the resultant yield are often underestimates of what nominal should be.

 

[Flaminpyro]

Yep most likely a wast of your time to buy them and do a test !

 

[Benm]

I'm already suspcious of 3000mah 18650s, for all calculations I still use "2200mah" for 18650. While it has not failed me yet, the resultant yield are often underestimates of what nominal should be.

Its probably a wise precaution - they may have more capacity initially, but half a year later this won't be the case anymore.

 

[BShanahan14rulz]

Yes, not to mention 2900mAh is the highest capacity with standard charge termination. Most 3000mAh cells require you to either discharge past the usual under-load cutoff voltage, or charge higher than the usual 4.2V charging cutoff voltage (4.35V or so).

 

[AJ_Dual]

I'm working on a 5000mah LiOn cell. They should be out to market within a month.

Why you ask are they 5000mah? Why, because it SAYS SO right on the wrapper.