Chapter 5. Battery changing
5.1 Charger box
The charger unit has been designed in conjunction with the OBS battery packs, so that it can charge the batteries in the shortest time possible. As mentioned in Section 4.5, there are 12 x 1S battery packs in the OBS and, for the charging, they are connected as three packs with 4S configuration. Each 4S pack has its own charger circuit, this allows to charge all cells in the Aquarius in a third of the time. The chargers monitor temperature, voltage and current of each 1S battery pack during the charging cycle.
Therefore, three battery chargers were installed in the charger unit, all three are connected to the OBS unit through the same cable described in Section 5.3. The charger unit voltage input is 85 V to 230 V AC.
Each of the chargers is equipped with a display and four control buttons:
Batt type / Stop
Dec / Status Decrement
Inc / Status Increment
Start / Enter
The charger unit is built into a Peli case so when properly sealed it is fully waterproof (IP67).
Warning: The charger unit is not waterproof when the lid is open. To dissipate the heat generated during the charging process, the unit was designed with ventilation fans and an outlet port.
Do not allow water into the unit when the lid is open.
5.2 Batteries charging specifications
Parameter | Value |
Batteries arrangement | 4S |
Nominal voltage per cell | 4.2V |
Maximum charging voltage per 4S pack | 16.8V |
Max charging current | 15A |
5.3 Charging cable
A 2.5 m charging cable, specifically designed for charging the Aquarius has been provided with the system. The cable has a thirty-two-way military-specification bayonet connector on both ends: the socket on the Aquarius canister side and the plug on the charger unit side.
For details about the pin-out, see Section 12.3.
The cable has a locking collar on the Aquarius end. When this is screwed down with the O-ring in place, the Aquarius canister will still be waterproof, allowing charge of the OBS under rain or sea salt sprays.
As warned in the previous paragraph, the charger unit will need to be sheltered while charging.
5.4 Charging the batteries
5.4.1 Connecting the charger
Using the special tool provided, undo and remove the cap in the centre of the OBS to reveal the charging connector.
Caution: It is important to use the tool provided to avoid damage to the protecting finish on the cap, which can cause corrosion.
The cable connector with the large black ring connects to the OBS canister. Check the alignment as the connector is pushed in and tightened by hand.
5.4.2 Operating the charger unit
Batteries should be charged according to the following steps:
Connect the cable as described in Section 5.4.1.
Power up the charger box using the IEC C13 mains power cable and press the
In each of the chargers, press the “Batt type” button under the battery charger display. “PROGRAM SELECT Lithium Battery” is displayed on the LCD.
Press “Start/Enter” button once and use the “Dec” and “Inc” buttons to move across the program types until “FAST CHARGE” appears.
Press the “Start/Enter” button and use the “Dec” and “Inc” buttons to move across the battery types until “LiPo” (Lithium Polymer) appears.
Press the “Start/Enter” button and use the “Dec” and “Inc” buttons to move across the current value until “15 A” is selected.
Press the “Start/Enter” button and use the “Dec” and “Inc” buttons to move across the voltage value until “16.8 V (4S)” is selected.
Press the “Start/Enter” button.
Press and hold the “Start/Enter” button until the charging starts.
The battery charger notifies with a “beep” when the batteries are charged and shows
the message “DONE” on the display, this will happen when the current reaches 3 A (⅕ of charging current equal to 15 A).
Push on the “Stop” button to interrupt the charging if required.
Note: Points 3 to 8. of the procedure above is required only if the battery charger loses its configuration. When the charger is switched off it maintains the configuration. Before shipment, the chargers were programmed with the correct settings. If no changes were applied to the original settings, you could execute steps 1 and 2 and then jump to step 9.
The complete user manual the battery charger is available at the link below