Great batteries 🔋 for the price!
Key Features
- High-Capacity Cell: 5000mAh nominal capacity optimized for energy-dense battery pack designs.
- High Continuous Discharge: Supports 25A continuous discharge, with up to 45A when managed with an 80°C temperature cutoff.
- Flat Top Configuration: Unprotected flat top design suitable for engineered battery assemblies.
- Wide Operating Temperature Range: Reliable operation from -20°C to 60°C.
- BIS Certified: Certified for use in India, meeting applicable regulatory requirements.
Overview
The Samsung INR21700-50S is a high-performance lithium-ion battery designed for applications requiring both high capacity and elevated discharge capability. Delivering 5000mAh of energy and a 25A continuous discharge rating, the 50S is ideal for energy-dense battery packs and high-drain systems. Its flat top, unprotected design allows for flexible integration into professionally managed battery assemblies, while Samsung’s advanced cell chemistry ensures consistent output and dependable performance.
Applications / Uses
- Electric vehicle battery systems
- Large-scale energy storage solutions
- High-drain industrial electronics
- Custom lithium-ion battery packs
- Commercial power systems
Specifications
| Manufacturer | Samsung SDI |
| Model | INR21700-50S (50S) |
| Size | 21700 |
| Positive Terminal | Flat Top |
| Nominal Capacity | 5000mAh |
| Continuous Discharge Rating (Max) | 25A (45A with 80°C cutoff) |
| Nominal Voltage | 3.6V |
| Maximum Voltage | 4.2V |
| Discharge Cut-off Voltage | 2.5V |
| Protected | No (Unprotected) |
| Rechargeable | Yes |
| Approx. Dimensions | 21.1mm x 70.7mm |
| Approx. Weight | 70.09g |
⚠ 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 123 reviews.
I had made my first purchase from IMR Batteries since my local websites that I used to get my Li-ion batteries no longer sell the Japanese or Korean ones and only Chinese models. I found this website on google search and had great feedback. I have purchased 18 pieces of these cells to make a 3S6P battery pack configuration (The parallel configuration since from online reviews these cells tend to heat up fast if drawn beyond 25A) as a replacement for my aged Samsung 24B 18650 battery pack of same configuration from 2019 I built. Decided to go for a larger capacity and higher current rating this time. They were shipped out and arrived fairly on time. Nicely packaged too. Got a good discount at $5 per cell. Each cell was exactly at 3.457V and charged up well. Put them through a discharge- charge cycle test and they perform well to my expectations!! 😊 Planning to order some Molicel batteries now to build a second pack! 😃 Had to delay the review as the item got held up in customs for a month due to the large quantity of cells. I do wish the seller accepted returns, but I understand why they refuse returns.
These batteries are the best and longest lasting for my application. Set at 17 watts, .36 ohms these batteries will last me almost 2 days of regular use. For perspective the best 18650's I reviewed a little while ago will last around 10 to 11 hours under the same load. A little smaller footprint, butnnot by much.
Good price....prompt shipping. Attached a photo of this battery putting out 3000lumens in a Convoy Flashlight
I'm very happy with the batteries, and they're great for my flashlight. Highly recommended.
Order came quickly, exactly what I ordered. Great price for the batteries, I'll order again when needed.
These batteries last all day!
Excellent product, I assembled everything and everything works.
Excellent product, I assembled everything and everything works.
Excellent Battery & Service!
So far the batteries work perfectly. I ordered 4 21700's and they all charge up to the same. I have run them down to about 25% and they all charge back up to around 3600 mah. Great batteries.
Very good batteries, no complaints and appear genuine
This cycling light is nice and bright but the battery quality is horrible! The manufacture basically told me to "throw away and but a new with a discount". Screw that! You guys had what I needed, I took apart the light, removed the crap batteries and re-installed the new ones...AND...it works great! Thanks!
It lasts about all day in my voopoo m100
Genuine cells at a fair price
Great Batts. for your Vape Mod! I use them in my mechanical Mod and they last more than just one day! I can get like 2 days out of them before I have to recharge them. And the service here is great too; they always get my order right the first time and quick delivery time too.
Installed these batteries in a battery pack I got from Aliexpress and I’m using them to Power my heated jacket. They are working perfectly.
Love these batteries. Bought 4 more. Able to get 12-14 hrs out of em at 53 watts. I'm a truck driver so changing batteries ever 2-3 hrs suck. So if u have a 21700 mod get these.
Fit good, looked Oem
Capacity upgrade for them long runtimes
Great price and fasttttt shipping. Solid batteries
Exactly what I needed! I purchased 12 batteries all were brand new and came in protective plastic cases. Thank you!!
Great cells for high capacity and decent discharge. Runs a little hot at max. I suggest to run it at half the rated ampacity to keep em cool.
This cels are an great option for my projects, all on good condition with same charge.
Samsung batteries still are amongst the best.
Provides power as expected from 5000 mA-hrs. My current needs are low, however: around 3 Amps.
I have been vaping with one of these for 5 days now and battery is still at 95%. They do take a while to charge but once they are, they are in it for the long haul.
Have used these to build all sorts of things, but primarily drone batteries. They stay practically cold even at high discharge. Amazing.
Power on tap for vaping, no heat issues. Excellent and recommended.
Great capacity! Just what I needed. Thanks.
Excellent product
Excellent product
Needed increased capacity. These significantly outlast my previous batts . Good price and fast delivery. Thanks!
Batteries worked great and shipped in faster than I was anticipating.
Great battery for my project.
Battery arrived promptly and in perfect condition.
i thought i was replacing the same kind of battery i have with one that would hold a charge longer, but the one i received is larger and will not fit.
Good cells, will buy from IMR again.
Everything was stellar in getting the batteries to me. My only complaint is that the batteries do not obviously indicate +/- poles. Yes, if I were to bet, the flat side appears to be the same (-) across all these battery types. However, when asking AI, the info was reversed for this battery. I ended up having to get a DMM to probe it out to be sure (my other DMM died, so I needed to replace it anyway). The battery is great. It works great. Getting it was quick and easy. The +/- indicators are blended into the information stamp on the battery is why it's not obvious.
Excellent batteries fast shipping