I’ve recently found a supply of diving lights from Hong Kong that are of reasonable quality and features at an price that makes them a top value. My new backup is 1600 LM T6 LED it comes with a battery holder module that takes 3 AAA batteries but can also run on a 18650 Li. One hour run time average. I just ordered another from the same company. It is rated at 4800 LM it uses 3 T6 LEDs runs on 2-18650 LI batteries and comes with them and a charger. Having tested the first backup light I ordered 10 for my shop and will be selling them for $45 each. I ordered 5 of the 4800 LM and anticipate similar run times and a sale price of $150 each.