To some, it may seem redundant, but to those who know, using a separate charging port for pen-style 510 threaded batteries are the best you can do to ensure optimum performance and longevity for your battery. This is the reason we created the DualCharge.
Our Dual Charge battery features two charging ports, one for 510 threaded chargers and the other for universal USB chargers at the bottom of the DualCharge vape pen. In our experience and the experience of our customers, we have noticed that threaded chargers can be finicky at times and overuse can lead to wear and tear on the threads which the cartridge also utilizes.
However, the primary reason for having a battery with separate charging ports is batteries like the Dual Charge last significantly longer with two ports. Separate charging ports do not rely on the same connection and therefore can charge and preserve your battery life better.