Tenergy Li-Ion 18650 Cylindrical 3.7V 2600mAh Flat Top Rechargeable Battery w/ PCB

by Tenergy

Product Details

• Shipping Weight: 3.2 ounces
• ASIN: B001JDRPXM
• Item model number: 30006
• Average Customer Review: 4.0 out of 5 stars  See all reviews (14 customer reviews)
• Date first available at Amazon.com: October 27, 2008

Product Description

Applications * Lighting or other device needing 3.7V power * Building portable power device needing high energy density and low weight Warning * Use special caution when working with Li-ion cells, they are very sensitive to charging characteristics and may explode if mis-handled. * Make sure user has enough knowledge on Li-Ion rechargeable batteries in charging, discharging and assembly before use. * Put the batteries in fire-proof container in charging * Do not put batteries on wood surface or carpet when charging * Never leave battery un-attended when charging * We are not resopnsible for damage if there is any modification of the batteries in form, shape or made into packs * We are not responsible for any damage caused by misuse or mishandling of these Li-Ion batteries Product Specifications * Capacity* Nominal 2600 mAh, Minimum 2450 mAh * Internal PCB protection prevents under-voltage at 2.5V and over-voltage at 4.25V. UNIQUE INTERNAL PCB! * Dimensions: Diameter 18+/-0.2 mm Height 66+/- 0.2mm * Weight (Typical) Approx. 46 g yes * Nominal Voltage: Average 3.7V * Cut-off Voltage: 3.0V * Internal Impedance: less or equal to 180 milliohm (with PTC) * Cycle Performance: 90% of initial capacity at 400 cycles * Cycle life: > 500 cycles * Charge: Current = 0.5C mA Voltage = 4.2 V End Current = 0.01 mA * Discharge: Current = 0.5C mA End Voltage = 3.0V * Max. Charging current: 1.5C ma * Max. Discharging current 1.5C ma (for continuous discharge)

Customer Reviews

Most Helpful Customer Reviews

70 of 76 people found the following review helpful:

5.0 out of 5 stars What the protection pcb does and why its so important, March 24, 2010

By 

HMMWV "God, Country, Corps" (santa clara, CA USA) - See all my reviews
(TOP 100 REVIEWER)    (VINE VOICE)   

This review is from: Tenergy Li-Ion 18650 Cylindrical 3.7V 2600mAh Flat Top Rechargeable Battery w/ PCB (Electronics)

We understand more now about lithium ion rechargable batteries than we did almost a decade ago. Back then, I designed products for Logitech to sell in the 100,000 qty that had a built in li-ion battery so the china company who made them came out to Fremont, CA and explained all the good, bad, and ugly about li-ion rechargables.

Back then the good was no memory effect, charge when you want to, and a high terminal voltage of 3.5 - 4.3 V depending on mfgr

The really bad is that just like we know every light bulb will eventually burn out, we also know that during the lifetime of the cell - at any random moment, 1 in 100,000 li-ion cells will either explode or catch fire (back then this made headlines because it usually happened in an airport and most flyers were a little edgy to begin with). The reason was that laptop battery packs often had 10-14 cells in them thus multiplying the odds of a failure to 1 in 10,000 which are pretty good odds that someone's laptop is either going up in flames or making a big boom.

Step forward 7-10 years

Now we have the protection pcb (printed circuit board). It prevents the li-ion cell from being overcharged or undercharged, both of which are dangerous regions to operate in. PCBs are often gold plated with 50 microinches of hard gold - you can see the underside of the pcb when you look at the tenergy battery. While the positive termial is just metal, the negative is gold. Not realy - inside there is a metal connection to the protection board, and the under side of it has a circular gold spot to make contact with the device springs. The second photo attached above helps to illustrate this with the wrapper removed.

When I bought my 18650 batteries on amazon recently there were 4 amp hour designs available: 2000, 2200, 2600 (these) and 3000. I chose the 2600 because it had the protection pcb in the package over the 3000 which normally I would jump at. It's a trade off - I'm giving up 400 mAh to get the insurance that my cell won't do anything nasty while being charged or discharged. (in actuality the 2600 mAh are turning out to be more like 2800 mAh as I discharge them in testing)

I'd recommend any li-ion cell TODAY that has the protection board built in. They are as safe as NiMH rechargables, and preliminary testing of these has shown they are actually about 2800 mAh instead of 2600 but I just got them in the lab and have not been able to draw any statistical conclusions on the design yet other than they are more than 2600.

EDIT 10/2011 - the 3000 mah cell ALSO has the protection pcb on it - so now no reason to stop at 2600. Also I failed to mention that there is a tradeoff in how you get capacity. These cells operate in the 3.5 to 4.2 V region per cell - so 10 cells in series coud have 35 to 42 volts on them. The tradeoff (you knew that was comming right) is that the higher the voltage you charge safely to, the shorter the lifetime of the cell. So you might get 50,000 charges out of the 3.8V cell - x 3AH or 11.4 AH in that cell, to 4.2 V in the same cell x 3AH - or 13.2 AH but maybe only 10.000 charge cycles. Often they aim it at the desired usage and profit scheme - if the cells are in an instrument that is expected to last for years, they run more cells at a lower voltage and do a dc/dc step down converter. if it is, say a mobile phone, where its lifetime is 2 years or less than 1000 charge cycles they may charge to a full 4.2 volts knowing 3.8 and 4.2 are both safe, but that the phone will wear out before the battery whereas the instrument (IV pump in a hospital etc) is going to be around for years as the technology does not change, so they will want the 3.8 VPC charge. Please don't let this muddy the waters - just think the more charge you put in - the shorter the life of the exact same battery. items that will only be charged 1000 times (e.g. cellphones) can even go to 4.3VPC safely for a little extra power over time.

It's nice to see modern flashlights using the 18650 cell - its a powerhouse as you can see with up to 13 WH per charge.

8 of 9 people found the following review helpful:

5.0 out of 5 stars Excellent, May 17, 2010

By 

P Beau "PB" (Los Angeles) - See all my reviews

Amazon Verified Purchase

This review is from: Tenergy Li-Ion 18650 Cylindrical 3.7V 2600mAh Flat Top Rechargeable Battery w/ PCB (Electronics)

I use these batteries in my high powered Fenix flashlight. They last forever. Really great batteries and well priced

6 of 7 people found the following review helpful:

5.0 out of 5 stars Does what it's supposed to. Great for flashlights., July 11, 2010

By 

Brian T. Baer "NY Ninja" (Long Island, NY USA) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Tenergy Li-Ion 18650 Cylindrical 3.7V 2600mAh Flat Top Rechargeable Battery w/ PCB (Electronics)

I use this in my Fenix TA-21 flashlight. It works great, holds a charge for a long time, and is easily recharged with a decent charger (though it takes a while to charge). It has the PCB protection which is great. The only thing some might not like about it is that there is no button top. If you are going to be using these types of batteries in a device that requires more than one of them, you might want to get one with a button top or put some solder on the positive terminal of one of them. Some flashlights (like mine) only require one of these batteries, and have springs to connect to both the positive and negative terminals, whereas the button top is not an issue.