As a custom lithium ion battery pack manufacturer for over 20 years, JBBATTERY has designed and built custom 18650 lithium ion LifePo4 battery packs with the simplest requirements to those with highly complex specifications. JBBATTERY is different from all other lithium ion battery companies due to the reliability and performance of our cells. lease visit https://www.jbbatterychina.com/custom-battery.html for more detail.