Is your battery refusing to fire, or firing weakly?
Firstly, check the tank or cart you're using with another battery, if possible, or check a new cart or coil on the battery in question. This will help you to rule out any issues with the cart/tank, as this could be 'dead' and thus the battery won't fire.
If the cart/tank works on another battery, we recommend to give the battery's connections a clean. You can see how to do this in the below video.
You may also need to raise the centre post in the battery connection, as over time this can become depressed and not create a solid connection with the tank/cart you're using.
To do this, take a pin and gently lever the post in the middle of the connection up, working your way around the post and levering it higher in several places around its edge.
Is your battery refusing to charge?
Firstly, check your battery with another charger, as it could be the charger at fault rather than the battery. If multiple chargers don't work, but you're using the same USB port or wall adaptor, we also recommend using a different port or adaptor to make sure that that isn't the part at fault.
If the issue is definitely with the battery, it could be a case of the battery not making a solid connection with the charger, so we recommend following the cleaning method shown in the below video, and raising the centre post as mentioned above.
If these tips don't get the battery working again for you, and it is with 42 days of purchase, it is within warranty so please contact our Customer Services team.