Refurbished a tool pack. Added 2 more Ah to the pack. Samsung cells are great. I always get great, real batteries from imrbatteries.com
Key Features
- High 4000mAh Capacity: Delivers long runtime for energy-intensive devices.
- Powerful 35A Output: Supports high-demand applications without voltage sag.
- 21700 Battery Size: Offers improved performance over smaller cell formats.
- Flat Top Design: Ideal for use in battery packs and custom builds.
- Rechargeable Cell: Designed for repeated use with consistent performance.
Overview
The Samsung 40T 21700 battery combines high capacity with exceptional power output. With a 4000mAh rating and a 35A continuous discharge capability, this battery is built to handle demanding applications that require both runtime and performance. Its flat top design makes it a reliable choice for professional and custom power solutions.
Applications / Uses
- Portable power equipment
- Electric transportation systems
- High-capacity battery packs
- Industrial electronics
- Advanced energy storage projects
SPECIFICATIONS
| Manufacturer: | Samsung SDI |
| Model: | INR21700-40T |
| Battery Size: | 21700 |
| Positive Terminal: | Flat Top |
| Nominal Capacity: | 4000mAh |
| Max Continuous Discharge: | 35A |
| Nominal Voltage: | 3.6V |
| Maximum Voltage: | 4.2V |
| Discharge Cut-Off Voltage: | 2.5V |
| Protected: | No, unprotected |
| Rechargeable: | Yes |
| Approx. Dimensions: | 21.1mm × 70.4mm |
| Approx. Weight: | 66.8g |
| Data Specification Sheet: | Samsung 40T Datasheet |
⚠ Important Safety Warnings
Improper handling or misuse of this lithium-ion battery can result in FIRE, EXPLOSION, or THERMAL RUNAWAY, causing personal injury, property damage, or death. Users must read and follow all safety guidelines before purchase and use. Click here to review the full safety guidelines.
- Critical Warning: Never carry loose batteries in your pocket, purse, or bag. Loose batteries can come into contact with metal objects like keys or coins, causing a short circuit, which may result in severe burns, fire, or explosion. Always store or transport batteries in a protective case or box.
- Intended Use: This battery is designed for integration into protected battery packs with a Battery Management System (BMS) or Protection Circuit Board (PCB). It is not intended for standalone use or use in devices such as e-cigarettes or vaporizers.
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What is Thermal Runaway?
- A dangerous chain reaction where heat generated by a failing battery causes it to overheat further, potentially leading to fire or explosion.
- Causes: Overcharging, short circuits, physical damage, or exposure to high temperatures.
- Prevention: Use a smart charger, avoid physical damage, and store batteries in a cool, dry place.
- Storage & Transport: Always store batteries in protective cases or boxes to prevent accidental contact with metal objects. Never store loose batteries in pockets, purses, bags, or near conductive materials.
- Inspection: Do not use if the PVC wrapper, terminal insulator, or casing is damaged, dented, leaking, or bulging. These are signs of internal damage or instability, and continued use could result in failure, fire, or explosion.
- Charging: Use a smart charger designed specifically for lithium-ion batteries and ensure that the charger's voltage matches the battery's specifications. Never overcharge, over-discharge, or leave unattended while charging.
- Prohibited Activities: Do not short circuit, modify, puncture, crush, expose to liquids, or solder directly onto the battery (spot weld only).
- Emergency Response: If a cell shows signs of thermal runaway (smoke, swelling, hissing, or heat), stop use immediately and, if it can be done safely, move it to a non-flammable surface (e.g., concrete or sand) away from combustibles. Lithium-ion cell fires are Class B fires — use an ABC/dry-chemical extinguisher, or douse with large amounts of water to cool the cell and prevent spread. Do not rely on a small spray; thorough cooling is required, and cells can reignite from residual heat, so monitor the area afterward. (Class D extinguishers are for lithium-metal batteries, not lithium-ion.) For any fire beyond a single small cell, evacuate and call emergency services.
Disclaimer
IMR Batteries is not responsible for any damages, injuries, or claims arising from improper use, handling, or failure to follow these safety guidelines. Lithium-ion batteries require strict adherence to all safety protocols.
It is the reseller's responsibility to ensure all product warnings and safety guidelines are effectively communicated to their customers. Some cells are sold in bulk packaging and are not individually packaged. Resellers must provide appropriate packaging for each individual cell sold and must not distribute cells loose, unprotected, or without a proper storage box or case.
Product compatibility is the sole responsibility of the customer. IMR Batteries does not guarantee compatibility with any specific device or application. We are not responsible for the design, assembly, performance, or safety of any battery pack constructed using our cells. It is the customer’s responsibility to ensure proper cell matching, protection circuitry, configuration, and safe construction practices. Users and resellers assume full responsibility for the safe handling, usage, and distribution of this product.
Customer Reviews
Overall rating: 4.8 / 5 from 392 reviews.
Perfect replacement for my repair of a Dewalt 20v battery. Works like a champ!! Quick shipping and secure packaging.
Used the batteries for my Convoy S21e flashlight. I went with IMR hoping they wouldn’t disappoint and they didn’t. Battery life holds up well for the light even on high mode. Been using the light a lot and the battery hasn’t died yet. Would definitely shop here again!!
I didn’t know these were the WRONG size, but they were in the section with 18650 batteries, but these are one size larger. And since these cannot be returned, maybe notating the description of the actual size (that these were 21700 size) that would be super helpful
Delivery was fast and packed very well. Batteries are working perfectly. I highly recommend this website as well as these Batteries
Awesome batteries 🤓
Fantastic batteries, they run my devices perfectly and are all day reliable ❤️
The battery is exactly what they had listed and it works great. I do think this has a better punch than the home runs and the Molicel
Work perfect!
They work great!
Great batteries
I've used these batteries for years, good long lasting batteries. I highly recommend them.
Love these batteries! Had to get an extra pair for myself and 1 extra for a friend. Highly recommended!
Cool
Cells came very well packaged with exceptional delivery time. All cells are quality, tested great and are perfect for many hobbies and devices.
Good
Always great service the batteries were perfect for my project love the free cases
I bought these when they were on sale that made it worth it but besides that i wouldnt buy them again. I have the white battery that lasts almost twice as long on a charge maybe I got a bad battery but proof is in the pudding.
No issue at all. Arrived in 7 days.
Great vendor to work with,price and fast delivery.Samsung is a great brand to work with.
Works perfectly in my vape machine thank you
batteries correspond to the declared characteristics
I will buy this item again!
Batteries are great, but shipping costs are high and slow
Great!
Going to use in DIY power bank but threw them into some various things in the mean time. They have been very impressive so far. And to top it off they were very inexpensive when I grabbed them. Definatly going to get some more if the price stays where it is.
Fast shipping, Great price and the batteries work as advertised! THANKS!!
At least this one had a picture with that it can't be used for vapes on it and I needed it.
These are by far one my personal favorite batteries. Fast shipping is also great!
Genuine batteries. Didn’t receive any battery wraps (as indicated on the invoice). However minor, didn’t get an IMR decal this time.
Just what I needed worked perfect
Just what I needed. Satisfied with my purchase. No problems with this battery. When in need, will be ordering again.
If you aren’t in a hurry, this product and supplier is hard to beat. It just takes a very long time e to get it. I was beginning to think it was shipping from outside the US.
I'm using this battery in a device that pulls on the batteries amperage pretty hard and it's got a nice solid delivery of power and has a reasonable lifetime before needing to recharge. For the money this is an excellent battery. Plus IMR was fast and the order I made was very complete.
They take a great charge, and last forever. Couldn't be happier!
So far they have fixed the bad battery pack
My older hohm tech batteries in a single battery mod where lasting about 5 hours. These ones last for about 11 hours. They charge relatively fast too. Will definitely purchase again.
So far so good. Easy charging and good runtime.
These are working very nicely for a custom device.
Genuine cells competetive price. Original replacement for Milwaulke battery packs.