18650 Lithium Ion Cells

Posted by Tielman E. on 22nd Apr 2018

What battery type powers most Powerwalls, e-bikes, e-boards, e-scooters, vaping machines, cell phones, power banks... and much more?

Lithium Ion batteries are the most pervasive battery type for good reason. 

They:

  • easily deliver 5 times more power than lead-acid, 
  • have been known to cycle 2000 times or more if treated well, 
  • they can be positioned upside down, 
  • don't need ventilation as they don't put out noxious gas, 
  • come in small form factors perfect for DIY battery construction

The 18650 is most popular form factor lithium ion and is called such because it is 18 mm wide and 65 mm tall. Other battery types are making their appearance - see our blog post here on the 20700 cells - but the 18650 is at the time of writing the most widely used and available cell type.

Our site is dedicated to both the 18650 and the emerging 20700 cell types so you are assured to easily select the right products to help you in your next DIY battery project.

18650 specifications

  • Nominal voltage 3.7v
  • Max charging voltage 4.2v
  • Max change / discharge current is cell-specific and should be looked up at this site: SecondLife Cell Database Query
  • Capacities range widely from 1,000 mAh to close to 4mAh (at the time of writing). Be wary of claims above this as they are most likely the rewrapped trash available on most market places. 

The 18650 cells we sell will last you a long time if you treat them well. They have been known to cycle over 2,000 times under the right conditions. To help extend their life, follow the below rules:

  • No trickle charging. Many lead acid battery chargers trickle charge but this can lead to severe battery deterioration so be sure to use a lithium ion charger (see our list here).
  • Never apply more than 4.2v to each cell
  • Keep within manufacturers recommendations for maximum charge and discharge currents
  • For optimum results only charge to 95% of maximum voltage (around 4v)
  • Never discharge beyond 2.7v
  • Limit the number of times you discharge below 3v
  • Use of a BMS will help you care for the cells and is recommended for most users that just want a battery that they can plug-in and use without worrying about the hassle of manually staying within the above constraints.

We don't sell anything that we haven't used before so you can trust that the products will help you complete your next battery project.

Please reach out to us if you have any questions on: info@hipstar.co.nz