Yes, what batteries do you have, and what method are you using for charging, do you charge via USB or do you have a dedicated charger? Using the USB port can cause the batteries to charge unevenly but also, it may place added stress on the batteries.
We need to know what batteries you are using and at what wattage you vape. If your batteries are severely underpowered, not authentic or bought from a reputable seller, that may be your issue. That can be fixed.
It could be a fault in the mod, but I'd work on ruling out battery issues first, as it may simply be the batteries. If your mod is still under warranty, make sure you get all your questions on here answered, so that you can "solve" the mystery of it being the mods or the batteries in case you DO need to warranty the device. Not saying you do, but if you are within the warranty period, keep an eye on how much more "warranty length" you have so you can contact the vendor if need bet.
Anna