Samsung cell INR21700-30T 3,7V 3000 mAh Spot welded
High-quality cells from the best suppliers
Compatible with a wide range of tools
High performance in all conditions
12-month warranty
Samsung INR21700-30T Cells
Original lithium-ion cells manufactured by Samsung with the designation INR21700-30T. These cells have a capacity of 3000 mAh and a current rating of 35A, ensuring reliable battery performance even under very high loads.


Ready-Made Cell Connectors
You can also order these cells with pre-attached leads, which allow for quick connection of electronics to the cell pack, BMS, or external contacts. Additionally, Kapton tape protects the pack against overheating and short circuits.
Spot Welds
Cells with visible spot welding marks on the terminals. The presence of welding marks does not affect their operation or safety. Welding marks are a natural result of the manufacturing or preparation process for integration and do not constitute a defect.

Suitable for:
- • Electric bikes and scooters
- • Power tool batteries
- • Energy storage systems
- • DIY battery building (with BMS)
- • Robotics and industrial applications
Not suitable for:
- • Vaping devices / e-cigarettes
- • Consumer electronics without protective circuits
- • Using batteries without proper casing or BMS
- • Children's toys
- • Non-professional DIY projects
General lithium-ion battery handling instructions
- ⚠️ Important safety note
- This cell is not protected and is not recommended for use in e-cigarettes, vaping devices, or similar consumer applications. Intended for professionals with appropriate BMS systems.
- Before installation
- Check all cells for damage, swelling, leakage, or corrosion.
- Ensure polarity is correct and contacts are clean.
- Do not mix different types or new with used cells.
- ⚙️ Cell characteristics
- Li-Ion: Nominal voltage ~3.7 V per cell (max 4.2 V / min 3.0 V).
- ? Charging
- Use chargers designed specifically for the cell type.
- Li-Ion: Always use a BMS system. Charge in a fireproof location.
- ? Storage
- Store in a cool (15–25°C), dry place away from sunlight.
- Li-Ion: Store at ~3.7 V (40–60% capacity).
- ⚠️ Safety tips
- Do not short circuit terminals or expose cells to fire, heat, or water.
- If overheating, swelling, or leakage occurs – stop use immediately.
- Do not puncture or open sealed cells.
- ♻️ Disposal
- All batteries must be taken to recycling points.
- Never dispose of in regular trash.
- Battery capacity
- 3000mAh
- Type of cells
- Lithium Ion
- Cell brand
- Samsung
Correct using the battery will allow you to enjoy its optimal operation much longer. Learn the golden rules you must follow to extend your battery life.
Temperature matters
Most of us have had the opportunity to find out for ourselves that extreme temperatures badly affect the performance of laptop batteries. Power tool batteries are also sensitive to the thermal conditions in which they operate. Therefore, the battery must not be overheated. If it works for a long time, it is a good idea to take it out of the machine for a quarter of an hour. When it cools down, you can restart it.
Avoid discharge
Another factor that affects battery life is the complete discharge of the battery. If we notice that the efficiency of our device is decreasing, it should be a signal for us to stop its operation. Then connect the battery for charging. Remember that deep discharge is a battery killer.
Give him a break
We don't only need a moment of respite. Your battery also deserves relaxation. Before properly charging it is a good idea to connect the battery for "free charge". This will lower its temperature. Only 5 minutes is enough to restore all parameters after intensive work and increase the efficiency of the proper charging process.
Proper storage
Proper storage conditions of the battery also significantly affect its operation. Unused battery should be charged to the level of 60-70%. It should be placed in a room where the temperature is positive.
Memory effect. How do I get rid of it?
This is a common phenomenon found in NiCd-based batteries. May reduce the maximum capacity of the battery. To avoid this, discharge the battery as much as possible and charge it to 100%. This process is best repeated every three cycles.
Proper use of the battery is not difficult. The above rules should become a habit for every user of power tool batteries. They will save you time and money.
Frequently asked questions ... and answers :-)
I changed the rechargeable battery from NiCd to NiMh. Will I still be able to use my old charger despite this change?
Both NiCd and NiMh cell based batteries are able to operate in the same voltage ranges. They also do not differ in charging current. So this means that there is no problem for a NiCd charger to support a NiMh battery - almost every NiCd charger should be able to handle it. If you have any doubts about the operation of batteries and chargers, please contact our customer service - we will be happy to answer them there.
Do I have to remove the battery from the device each time I finish working?
An unused battery can be left in the device. However, it should be remembered that when it is left there for a long time, it may discharge. To prevent this from happening, it's best to charge it to a level equal to or greater than 60%.
Why is the battery life not always equal to the guaranteed?
This is because the battery life depends on the load on the battery at any given time. Activities such as driving screws use less energy than using a chainsaw. In the first case, the battery will last us longer, in the second, with a current flow above 25A, definitely for a shorter time.
What is the difference between NiCd and NiMh batteries?
NiMh cells are newer models than NiCd cells. The most important advantages they stand out are that they have no memory effect and that their energy density is higher. As a result, NiMh batteries can be recharged at any time without losing their capacity.
Can the old battery be recovered?
If you have a battery that you want to regenerate, please contact our customer service department. We accept almost all, as much as 95%, batteries for regeneration. We have the conditions to prepare almost every cell package available on the market. However, you must remember that the price of the service does not only consist of the cost of the necessary materials. You have to add the cost of the service technician's work.
If I have purchased a battery that does not match my equipment, can I return it?
As we have been selling online for many years, we have extensive experience with this type of situation - we know that mistakes happen. Trying to meet the expectations of customers and not to make them unpleasant disappointment, we have agreed that everyone who buys any product from us has 14 days from the date of purchase to return it.