Samsung 40T 21700 4000mAh 35A Battery

Samsung 40T 21700 4000mAh 35A Battery

Regular price $8.49
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The Samsung 40T 4000mAh Battery is the top tier battery and a great upgrade for any 21700 flashlight. It's always great to have a backup ready too.

 - Flashlight not included - 

Here are GENUINE Samsung 40T  cells 

Samsung 40T 21700 cells are 4000mah capacity when new and these test consistently slightly above that rating which is why some are labelled 4000mah and others are labelled 4000mah. They are all the same cells. Since these are EV cells they are perfect for any application like flashlights, DIY powerwalls, EV conversions, mobile solar generators, etc.



Manufacturer Samsung SDI
Model 40T (3)
Size 21700
Positive Terminal
Flat Top
Nominal Capacity 4000mAh
Continuous Discharge Rating (max) 35A
Nominal Voltage 3.6V
Maximum Voltage 4.2V
Discharge cut-off Voltage 2.5V
Protected No
Rechargeable Yes
Approx. Dimensions 21.1mm x 70.4mm
Approx. Weight 68.2g
Country of Origin Republic of Korea
Associated Names INR21700-40T
Data Specification Sheet Samsung 40T (3) Datasheet
Misusing or mishandling a lithium-ion battery may cause a FIRE or EXPLOSION which can result in INJURY or DEATH. 


Customer Reviews

Based on 3 reviews
Michael Meadows (Cape Coral, US)
Strong and long lasting!

I've yet to recharge either of the batteries purchased for use with the LEP flashlight I ordered. I think each battery has lasted well over 24 hours of intermittent use in the light, being used for fun to conduit for electrical/ fiber optic cables.

JRW (Cincinnati, US)
Nice upgrade

I bought these 5000 mah batteries as a 25% upgrade to the 4000 mah batteries that came with the Reylight Quad Emitter flashlight. More power and the same weight. Makes a great flashlight even better.

BUSS (Denver, US)
Good but Be aware

Haven’t used these yet to their fullest extent but they do work in my Reylight Quad Emitter Dawn Custom Maratac™ LED Flashlight + Glow Afterburner ( Gen 2 ). However you cannot use the Magnetic Bi-Direct Smart Battery Charger to charge them. Only works with the Pro Intelligent Battery Charger.

Zulu™ & Maratac™ Are Registered Trademarks Of CountyComm
WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to

Warning: This product may contains chemicals, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to