Please note: each unit is tested to its rated depth.
The RB Guardian uses a standard AA-size Nickel Metal Hydride battery. To ensure a compatible charger is obtained, please ensure that the charger can charge individual AA batteries (some require two at a time) and that it does not use a timer basis for battery charging. It must have overcharge protection such as voltage gradient disconnection (but not temperature controlled) and ideally faulty cell detection. A good worldwide option is the Ansmann Powerline4 traveller.
This charger is available from underwater experiences.