Try these troubleshooting tricks at home, you can fix your light on your own!
Please make sure to take the battery out of the charger before plugging into the wall, then insert the battery into the charger once the charger is plugged into the wall. You should see a green light when the charger is plugged into the outlet without a battery inserted, insert the battery and the charger should show a red indicator. This indicates the battery is charging.
Please clean off both side of battery before inserting into the charger to ensure proper connections.
Please make sure you are using a Bigblue Battery. Using an off-brand battery can result in a malfunction light.
If you charger is not turning red once battery is inserted, you can spin the battery around or remove the battery and insert it again.
Make sure that the batteries are making good connections by cleaning the threads on both the light head and the body. Check the connections to assure that there is no rust or corrosion on them.
Sometimes the spring on the inside of the body gets compressed; you can try pulling that spring out of the light and stretching it to provide a stronger battery connection.
Try placing your light in a freshwater soak for 24 hours. This often frees up any salt or sediment which can build up under the switch.
Bigblue Dive Lights – Troubleshooting Tips, Try these at home! – YouTube
Battery charging guide
18650 – 3-4hrs
26650- 5-6hrs
32650 -6-7hrs
18650×4 – 2-3hrs
18650×4 SUPREME – 5-6hrs
18650×7 – 2-3hrs
21700×4 – 2-3hrs
21700×4 – 2-3hrs