Since day 1 when Retra introduced their underwater flash system, we were advised to use Eneloop pro AA Rechargeable NiMH Batteries which individually have a battery voltage of 1.2 V with 2550 mAh / 3.06 Wh
Now with 8 of these batteries bundled together you then have 9.6 V, but your battery capacity is still going to provide 2550 mAh / 3.06 Wh.
Whereas with 8 EBL AA Li-ion batteries which have a battery Voltage of 1.5V with 2200mAH / 3.3 Wh individually are bundled together will then have a total voltage of 12V, yet the battery capacity for all 8 together remains at 2200mAH / 3.3 Wh.
While it was advised to stay away from the latter, now comes Retra’s new Power Vault Li-Ion battery pack which is stated to provide 7.2V with a battery capacity of 5555.56 mAh / 40 Wh.
To me, this is a bit of a head scratcher.