Samsung 21700-40T 4000mAh 35A Battery

7,99 €

Type: 21700
Capacity: 4000mAh
Dimensions: (Height) 70.1 mm (Diameter) 21 mm
Voltage: 3.6V
Maximum continuous discharge current: 35A

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Samsung INR21700-40T 4000mAh Rechargeable Battery

The Samsung INR21700-40T is a high-performance 21700-format rechargeable battery with a rated capacity of 3900mAh and a standard capacity of 4000mAh. It is designed for devices that require a high discharge current.

The maximum continuous discharge current reaches 35A with thermal shutdown and 45A with shutdown at 80°C. This makes it suitable for demanding applications with high power loads.

Technical Specifications

Specifications	Value
Brand	Samsung
Model	INR21700-40T
Category	Rechargeable battery
Rated Capacity	3,900 mAh
Standard capacity	4,000 mAh
Rated voltage	3.6 V
Standard Charging	CCCV, 2A, 4.20V, 200mA cutoff
Nominal Charge	CCCV, 6A, 4.20V, 100mA cut-off
Maximum continuous discharge	35A with thermal cut-off
Maximum Continuous Discharge (High)	45A with thermal cut-off at 80°C
Breakdown voltage	2.5 V
Life Cycle	250 cycles to 60% capacity with a 6A charge and a 35A discharge

A battery with or without protection—what's the difference?

Protected batteries contain a small electronic circuit board located in the anode or cathode. It protects against overcharging, over-discharging, and excessive current—when a critical value is reached, the protection circuit shuts down the battery.

Protected batteries are suitable for flashlights with mechanical reverse-polarity protection. These include flashlights from brands such as Acebeam, Olight, Fenix, Nitecore, and Armytec. However, they are not compatible with flashlights such as Zebralight and Dulotec devices, which are designed for unprotected batteries.

Protected batteries are slightly longer and wider than standard ones. Some flashlights require a higher current, which protected batteries cannot provide. To make the right choice, measure the size of the original battery in mm and compare it with the technical specifications.

Safety Rules for Use and Storage

Improper use may result in a fire or explosion. Follow these guidelines:

Do not alter, modify, disassemble, drill, cut, crush, or short-circuit the device.
Do not expose the battery to water, fire, or high temperatures.
Do not use in defective devices.
Do not throw into a fire.
Do not overcharge, do not undercharge, and do not charge at sub-zero temperatures.
Do not use if the foil is damaged or compromised.
Do not store in a pocket or purse—use a protective case.

Frequently Asked Questions

What is the capacity of the Samsung INR21700-40T battery?

The Samsung INR21700-40T battery has a rated capacity of 3,900 mAh and a standard capacity of 4,000 mAh. The rated voltage is 3.6 V. These specifications make it suitable for devices with higher power consumption.

What is the maximum discharge current of the Samsung INR21700-40T?

The maximum continuous discharge current is 35A with thermal shutdown. In a higher-current mode, the battery can operate at 45 A, with shutdown occurring when the temperature reaches 80°C. The discharge cut-off voltage is 2.5 V.

How many charge cycles does the Samsung INR21700-40T battery last?

The cycle life is 250 cycles at 60% of capacity under conditions of 6A charging and 35A discharging. This is the standard specification provided by the manufacturer for these specific operating parameters.

What is the difference between a battery with protection and one without?

Protected batteries have a built-in circuit board that protects against overcharging, over-discharging, and excessive current. When a critical threshold is reached, the protection circuit automatically shuts down the battery. Protected batteries are slightly longer and wider than standard ones due to the added components. Unprotected batteries are more compact and can deliver the higher current required by certain devices.

For which flashlights is a battery with protection suitable, and for which ones is one without protection suitable?

Protected batteries are suitable for flashlights with mechanical reverse-polarity protection, such as those offered by Acebeam, Olight, Fenix, Nitecore, and Armytec. Zebralight flashlights and Dulotec devices are designed for unprotected batteries and are not compatible with the longer protected versions. Before purchasing, it is recommended that you measure the size of the original battery and compare it with the technical specifications.

How do we choose the right battery for our flashlight?

The surest way is to measure the dimensions of the original battery in millimeters and compare them with the technical specifications of the new battery. It is important to check whether the flashlight requires a battery with or without protection. If necessary, you can contact the Dulotec.COM team to determine the right option for your device.

What are the rules for safely storing the Samsung INR21700-40T battery?

The battery must be stored in a protective case—never in a pocket or bag without protection. It must not be exposed to water, fire, or high temperatures. Charging at sub-zero temperatures is prohibited. Do not use the battery if its foil is damaged or compromised. Following these rules reduces the risk of fire or damage.