Introduction
The GP PB320 GS-UC1 PowerBank S320 is a universal constant current charger designed for NiMH rechargeable batteries. It features a timer-controlled charging process, ensuring optimal charging for specific battery capacities. This manual provides essential information for the safe and efficient operation of your charger.
Safety Information
- Use only NiMH rechargeable batteries. Do not attempt to charge alkaline, carbon-zinc, or other non-rechargeable battery types.
- Ensure correct battery polarity (+/-) when inserting batteries into the charging slots.
- Do not expose the charger to rain, moisture, or extreme temperatures.
- Avoid disassembling or modifying the charger. Refer all servicing to qualified personnel.
- Keep the charger away from children and pets.
- Unplug the charger from the power outlet when not in use or before cleaning.
- The charger is designed for indoor use only.
Product Features
- Timer-controlled charging process.
- Charges 1-4 NiMH AAA, AA, C, or D batteries.
- Charges 1-2 NiMH 9V batteries.
- Automatic charging current setting.
- Individual charging channels for AA, AAA, C, D batteries.
- Independent charging channels for 9V batteries.
- Discharge function for battery conditioning.
- Battery status check.
- LED indicators for charging status.
- Trickle charge capability.
Package Contents
- 1 x GP PB320 GS-UC1 PowerBank S320 Universal Charger
Setup
Follow these steps for initial setup of your GP PowerBank S320 charger:
- Unpack the charger from its blister packaging.
- Place the charger on a flat, stable surface in a well-ventilated area, away from direct sunlight or heat sources.
- Connect the charger's power cord to a standard 230V AC / 50 Hz electrical outlet.

Image: Front view of the GP PB320 GS-UC1 PowerBank S320 Universal Charger, showing the battery compartments, LED indicators, and control buttons.
Inserting Batteries
Carefully insert NiMH batteries into the appropriate charging slots, ensuring correct polarity. The charger supports various battery sizes:
- AAA, AA, C, D Batteries: Insert 1 to 4 batteries into the main charging channels.
- 9V Batteries: Insert 1 or 2 9V batteries into the dedicated 9V charging slots.
Operating Instructions
Once batteries are correctly inserted and the charger is plugged in, the charging process will begin automatically. The charger uses a timer to determine the charging duration, which is preset and cannot be manually adjusted. This design ensures optimal charging for batteries within specific capacity ranges.
Charging NiMH Batteries (AAA, AA, C, D)
Insert 1 to 4 NiMH batteries of AAA, AA, C, or D size into the corresponding slots. The charger will automatically detect the battery type and begin charging at a constant current of 270 mA per channel. The LED indicator for each channel will illuminate to show charging status.
Approximate Charging Times (for reference):
- AA 1300 mAh: 5 hours 30 minutes
- AA 2700 mAh: 10 hours 30 minutes
- AAA 650 mAh: 2 hours 45 minutes
- AAA 1000 mAh: 4 hours 15 minutes
- C 3500 mAh: 14 hours 30 minutes
- D 4500 mAh: 18 hours 50 minutes
Charging NiMH 9V Batteries
Insert 1 or 2 NiMH 9V batteries into the dedicated 9V slots. The charger will supply a constant current of 13 mA. The LED indicator for the 9V channels will show charging status.
Approximate Charging Time (for reference):
- 9V 200 mAh: 17 hours 00 minutes
Discharge Function
The charger includes a discharge function to help condition batteries and reduce memory effect. To use this function, refer to the specific controls on your charger (e.g., a 'Discharge' button or switch). Once activated, the charger will discharge the batteries before initiating the charging cycle.
LED Indicators
The charger is equipped with LED indicators to provide visual feedback on the charging status. Refer to the markings on your specific unit for detailed interpretation of the LED states (e.g., solid light for charging, off for complete, blinking for error).
Maintenance
Cleaning
To clean the charger, first unplug it from the power outlet. Use a soft, dry cloth to wipe the exterior. Do not use liquid cleaners, abrasive materials, or solvents, as these can damage the unit.
Storage
When not in use, store the charger in a cool, dry place, away from direct sunlight and extreme temperatures. Ensure no batteries are left in the charging slots during storage.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Batteries not charging / LED not illuminating. | Charger not plugged in; incorrect battery insertion; non-rechargeable batteries. | Ensure charger is securely plugged in. Re-insert batteries, checking polarity. Confirm batteries are NiMH rechargeable type. |
| Batteries slip out of holding spring. | Loose spring mechanism or improper battery placement. | Carefully re-position batteries to ensure they are securely seated in the spring mechanism. |
| Charger feels warm during operation. | Normal operation. | It is normal for the charger and batteries to become warm during charging. Ensure adequate ventilation. If excessively hot, unplug and allow to cool. |
| Batteries not fully charged after expected time. | Battery capacity mismatch with charger's timer; old/worn batteries. | This charger is designed for specific capacities. If batteries are lower capacity, they may not reach 100% charge. Consider replacing old batteries. |
Specifications
| Feature | Detail |
|---|---|
| Model | PB320 GS-UC1 |
| Battery Type Supported | NiMH |
| Battery Sizes Supported | AAA, AA, C, D, 9V |
| Number of Charging Channels | 4 (for AAA/AA/C/D) + 2 (for 9V) |
| Input Voltage | 230 V AC |
| Frequency | 50 Hz |
| Charge Current (AAA, AA, C, D) | 270 mA |
| Charge Current (9V) | 13 mA |
| Operating Temperature | 0 °C to 40 °C |
| Dimensions (L x W x H) | 210 x 105 x 59 mm (8.27 x 4.13 x 2.32 inches) |
| Weight | 630 g (1.39 lbs) |
| Discharge Function | Yes |
| Trickle Charge | Yes |
| Damaged Battery Detection | No |
| Reverse Polarity Protection | No |
| Alkaline Battery Detection | No |
Warranty Information
This product is covered by a manufacturer's warranty against defects in materials and workmanship. The specific terms and duration of the warranty may vary by region. Please retain your proof of purchase for warranty claims. For detailed warranty information, refer to the documentation included with your product or contact customer support.
Customer Support
If you encounter any issues or have questions regarding your GP PB320 GS-UC1 PowerBank S320 charger that are not addressed in this manual, please contact GP customer support. Contact information can typically be found on the product packaging or the official GP website. Please have your product model number and purchase details ready when contacting support.