Foursevens 16650

$15.00

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QTY

Product Overview

FOURSEVENS 16650 (2200mAh) Rechargeable Li-Ion:
WORKS WITH: Quark QK16L (and other legacy Quark Click/Pro/Tactical (also other 4.2V two cell lights). Does NOT work with the Quark Smart.)

Prometheus In the Wild

Product Details

We finally made the leap and now have our own customized batteries! As you know, I'm obsessed with quality and these li-ion cells are top of class and are guaranteed to deliver.

What you get for your money:

Reliability: Less chance the cell stops working for no apparent reason (it happens)
Consistency: Every battery has similar performance (as opposed to variable)
Safety: Mechanical and electronic safety features (a "protected" cell)
Lifetime: Longer total life span because of the characteristics above

Why did we discontinue the 2xCR123 platform?

Because we believe that running a light with 2x(R)CR123 is dangerous. Using two cells in series creates a significant chance of catastrophic failure if the batteries become imbalanced. Imbalance can be caused by batteries of different age, manufacturing defect, or difference in charge state. For example, you accidentally put in a charged battery with a discharged battery. This imbalance can lead to fire or explosion in one of the cells.

This is not uncommon. Even if you think you are diligent, why take the risk when a much better option is available? This is also why we are no longer shipping any Foursevens lights with 2xCR123 cells.

Theoretical Run Time Comparison @ 1A:

Foursevens 16650 2200mAh = 3 hours
2xRCR123 750mAh = 2 hours (poor capacity & explosion risk)
2xCR123 1500mAh = 3 hours (good capacity but explosion risk)

This rechargeable 16650 battery has capacity equal to 2xCR123 cells and significantly more capacity than 2xRCR123 cells. The upcoming Quark QK2L 16650 will ship with this battery included, but we highly recommend using this battery in all of your two cell lights that are compatible with 4.2V.

Recharge early and often!

Do not run rechargeable batteries until they are completely empty (when the light shuts off on its own). Doing so will trip the protection circuit and render the battery inoperable. The Foursevens Flex Charger and Xtar VC2/VC4 chargers are normally able to reactivate a tripped battery; however, best practice is to recharge early and often. Fully discharging the battery causes long term damage to the cell.

Storage

ALWAYS store batteries in a protective case that will prevent short circuits. NEVER put bare cells into a pocket, bag, or drawer. A short circuit will lead to an uncontrolled release of energy...otherwise known as a ball of molten lava.

Do batteries have a "memory" effect I should worry about?

NO. Modern rechargeable batteries (Li-Ion or NiMh) do not have any memory effect. It's best practice to recharge early and often. In fact, fully depleting a battery will damage it and reduce the overall capacity.

what is the shelf life of a charged battery?

Generally speaking, all our batteries will retain 80% of their charge after six months. People worry about this more than they should. Modern batteries hold a charge for a long time. Just charge them and put them away properly. You should charge batteries once a year. Putting them in the fridge is also a myth. Don't do it.

Does heat or cold have a negative effect?

Li-Ion and NiMh batteries can be operated in sub-freezing temperatures. However, a cold battery will deliver less capacity (run time) than expected. Batteries should ALWAYS be at room temperature before charging. Charging a frozen battery can permanently damage the cell and lead to an internal short circuit. In a Li-Ion battery this can cause a fire. Most batteries can tolerate heat up to about 104F/40C. You should never leave a light (or any device) inside a car and exposed to direct sunlight.

Should I leave batteries on my charger all the time?

NO. It's best practice to remove batteries from the charger once they are fully charged. It also depends on the quality of your charger, but again, best practice is to remove the batteries. Some low quality chargers can create a risk of fire.

Can I install batteries backwards to prevent accidental activation?

NO! Back in the day people would install batteries backwards in a light for storage and to prevent the light from turning on by accident. You should NEVER install batteries backwards in electronic devices.

Protection Circuit

These batteries contain a specialized electronic "protection circuit" for user safety. The prevents short circuit, over charge, over discharge, over voltage, and under voltage conditions. Li-Ion batteries contain a massive amount of energy and you don't want to mess around with that. A protection circuit is like the seatbelt in your car. You don't want to use it, but it's there if you need it. Some people think flashlights have built in features to prevent accidents, but this actually FALSE. Those features are meant to protect the light, not the battery or your person/property.
We ALWAYS recommend the use of "protected" batteries, excluding special circumstances.

impact resistant wrapper

A special heavy-duty wrapper material resists cracking, unlike standard battery wrappers. This does make our batteries slightly thicker than comparable cells.

Premium cells

We use only top quality cells from reputable manufacturers. Obviously we recommend our own batteries because we can guarantee the quality, and our lights are designed specifically to work with these batteries. NEVER (ever) purchase Li-Ion batteries on eBay because of rampant counterfeiting and sub-standard quality. These batteries can be dangerous and lead to fire and/or explosion. Saving a few bucks isn't worth burning down your house with your family inside.

Size

16650 (16.5mm x 69mm)
Weight

2.0 Oz
Terminal Type

"Button Top"
Voltage

3.7V Nominal (4.2V full charge)
Capacity

2200 mAh

Service Life

~500 Cycles
Charge Retention

80% @ 6 Months
Maximum Discharge

4.4 Amps @ 2C
Electronic/Mechanical Protection

Over charge, over discharge, over voltage, under voltage, short circuit
Where it's made

Customer Reviews