Types of 18650 battery

There are two main categories for 18650 batteries, protected 18650 batteries and unprotected 18650 batteries.

Protected 18650 battery

It is important to know that these protected batteries include a charge and discharge protection circuit, known as a BMS, PCB or PCM. This circuit prolongs the life of the battery, makes it safer, and reduces the risk of explosion.

Firstly, we are going to write about the protected 18650 batteries. These type of battery has an integrated circuit in the extreme making it a safer battery as we have already mentioned before.

Why the protected battery is the safer option

This circuit protects against:

  • Excessive dangerous charging and discharging
  • Circuit breaks
  • Extreme temperatures

It is designed to protect the dispositive where we use these type of batteries and prevent damage from possible explosion or leakage.


Protected USB 18650 battery

Within the protected 18650 batteries you can find the protected with USB. This one makes you easier to charge the battery without the need of a battery charger. On the other hand, you must to be careful because sometimes are a little longer and sometimes it doesn't fit in your device. So in this cases the returns are allowed within 14 days, but unused (not loaded or unloaded) and without damage.

We highly recommended this type of batterys for flashlights because the circuit of the protected 18650 battery you avoid overcharging, discharging and short circuit. These batteries are usually +-69mm long.

Unprotected 18650 battery

Secondly, we have the unprotected 18650 batteries, these rechargeable unprotected batteries use to be a bit unsafe because do not have this internal circuitry as the protected batteries.

Recommendations for unprotected 18650 batteries

  • Look carefully to the discharge rating to make sure to not draw too much power from a cell or overheat.
  • You should also keep the contacts covered, preferably in a plastic box.
  • You will also need to make sure that you do not leave your batteries in the charger for too long. 

Within this unprotected 18650 batteries you can find different types, button top battery, flat top battery, refurbished battery and the u-tag battery. These unprotected batteries used to have a length of 65 mm long.



Unprotected BUTTON TOP battery

This one is highly recommended for doorbells with camera and some high drain flashlights.


Unprotected FLAT TOP battery

If you are thinking creating a battery pack this is your battery.


Unprotected REFURBISHED battery

It is the best option if you want a cheap battery.

These cells comes from rejected battery packs (due to problems with spot welding or batteries).

The cells we offer have:

  • No physical damage to cell
  • Never charged during production (as as from the box) (each cell is tested)
  • Resistance is according to datasheet, never worse (each cell is tested)


Unprotected U-TAG battery

Perfect option if you want to build a small battery pack.

We hope this post has helped you. If you want to know more about a specific 18650 battery topic, please let us know in the comments of the post.