1. Inleiding
The GYSFLASH 12.12 is an advanced 12V 12A smart battery charger designed for optimal charging and maintenance of various 12V lead-acid batteries, including those found in cars, utility vehicles, motor homes, buses, commercial vehicles, and agricultural equipment. This manual provides essential information for safe and effective operation of your GYSFLASH 12.12 charger.
It features an 8-step intelligent charging curve to ensure maximum battery performance and longevity, along with specialized modes for different battery types and conditions.
2. Veiligheidsinstructies
Read all safety warnings and instructions carefully before using the charger. Failure to follow these instructions may result in electric shock, fire, or serious injury.
- Always ensure proper ventilation during charging to prevent gas accumulation.
- Do not charge frozen batteries. Allow them to warm up before charging.
- Vermijd vonken of vlammen in de buurt van de accu tijdens het opladen, aangezien accu's explosieve gassen kunnen afgeven.
- Draag oogbescherming en beschermende kleding wanneer u met batterijen werkt.
- Disconnect the AC power supply before making or breaking connections to the battery.
- This charger is designed for 12V lead-acid batteries only (WET, MF, Ca/Ca, AGM, GEL, EFB). Do not use it for other battery types.
- The charger is protected against short circuits, polarity reversal, and overcharging. It also features anti-spark technology.
- The GYSFLASH 12.12 has an IP65 rating, indicating resistance to dust and water ingress. However, avoid submerging the unit.

3. Product voorbijview
The GYSFLASH 12.12 is a compact and robust battery charger. Key components include:
- Hoofdeenheid: Houses the charging electronics, control panel, and indicators.
- Configuratiescherm: Features LED indicators for charging status, selected mode, and potential errors.
- Modus Selectie Knop: Used to cycle through available charging modes.
- Batterij Clamps/Terminals: Rood voor positief (+), zwart voor negatief (-).
- Wisselstroomkabel: Connects the charger to a standard wall outlet.
- Externe temperatuursensor: Automatically adjusts the charging curve based on ambient temperature for optimal performance.

4. Installatie en verbinding
Follow these steps to safely connect the GYSFLASH 12.12 charger to your battery:
- De batterij voorbereiden: Zorg ervoor dat de accupolen schoon en vrij van corrosie zijn. Als u een accu in de auto oplaadt, zorg er dan voor dat het contact van de auto is uitgeschakeld en dat alle accessoires zijn losgekoppeld.
- Aansluiten op de batterij:
- Sluit de rood (+) charger clamp/terminal naar de positief (+) batterij aansluiting.
- Sluit de zwart (-) charger clamp/terminal naar de negatief (-) batterij aansluiting.
- For in-vehicle batteries, if the battery is not grounded to the chassis, connect the black (-) clamp to the negative (-) battery terminal. If the battery is grounded to the chassis, connect the black (-) clamp naar het chassis van het voertuig, uit de buurt van de accu en de brandstofleiding.
- Aansluiten op stroom: Plug the charger's AC power cable into a standard electrical outlet. The charger will power on.
- Selecteer modus: Press the mode selection button to choose the appropriate charging mode (see Section 5).
To disconnect, first unplug the charger from the AC outlet, then disconnect the black (-) clamp, gevolgd door de rode (+) clamp.

5. Bedrijfsmodi:
The GYSFLASH 12.12 offers several operating modes to optimize charging for different battery types and conditions. Use the mode selection button to cycle through these options.
- Normal Charge Mode: Standard charging for most 12V lead-acid batteries (WET, MF, Ca/Ca, GEL).
- AGM-modus: Specifically designed for cold weather charging (below 5°C) and for Start & Stop batteries (EFB & AGM types). This mode adjusts charging parameters for these specific conditions.
- Vernieuwingsmodus: Used to recover deeply discharged batteries. This mode attempts to recondition batteries that have been left discharged for extended periods.
- Leveringswijze: Transforms the charger into a stabilized power supply. This mode is useful for:
- Maintaining battery health during vehicle demonstrations in showrooms.
- Preserving vehicle memory settings (e.g., radio codes, ECU data) during battery replacement.
The charger also features an Optimized Maintenance Charge, allowing it to remain plugged in indefinitely during winter months to maintain battery health without overcharging.

6. 8-Step Intelligent Charging Curve
The GYSFLASH 12.12 utilizes an advanced 8-step charging curve to ensure efficient, safe, and complete charging, maximizing battery lifespan and performance. The external temperature sensor automatically adjusts this curve based on ambient conditions.
- Analyse: Assesses battery condition and initial charge level.
- Herstel: Initiates a gentle charge for deeply discharged batteries (SOS Recovery for batteries >2V).
- Test: Checks battery's ability to accept charge.
- Desulfatering: Applies a pulsed charge to break down lead sulfate crystals, restoring battery capacity.
- Aanval: Bulk charging phase, delivering maximum current until the battery reaches approximately 80% capacity.
- Absorptie: Gradually reduces current while maintaining voltage to bring the battery to 100% charge.
- Vernieuwen: (If selected or needed) Further reconditions the battery.
- Drijvende lading: Houdt de batterij volledig opgeladen met een laag, constant volumetage, preventing self-discharge.

7. Onderhoud
Proper maintenance ensures the longevity of your GYSFLASH 12.12 charger and the batteries it charges.
- Onderhoud van de oplader:
- Houd de oplader schoon en droog. Veeg hem af met een zachte, droge doek.amp lap. Gebruik geen oplosmiddelen.
- Bewaar de oplader op een koele, droge plaats wanneer deze niet in gebruik is.
- Controleer kabels en klemmenamps regularly for damage. Replace if necessary.
- batterij zorg:
- Zorg ervoor dat de accupolen schoon en vrij van corrosie zijn.
- For conventional lead-acid batteries, check electrolyte levels periodically and top up with distilled water if needed (do not overfill).
- For optimal battery health, use the maintenance charge feature during long periods of inactivity.
8. Probleemoplossing
If you encounter issues with your GYSFLASH 12.12, refer to the following common problems and solutions:
| Probleem | Mogelijke oorzaak | Oplossing |
|---|---|---|
| De oplader gaat niet aan. | No AC power; faulty power cable. | Check AC outlet and power cable connection. Try a different outlet. |
| Charging indicator not active. | Onjuiste batterijaansluiting; batterijspanningtage too low; incorrect mode selected. | Verify positive/negative connections. Ensure battery voltage is above 2V for recovery. Select appropriate mode. |
| Fout-LED brandt. | Polarity reversal; short circuit; internal fault. | Disconnect charger, check connections for correct polarity. Inspect cables for damage. If error persists, contact support. |
| Batterij niet volledig opgeladen na langdurig gebruik. | Battery deeply discharged or sulfated; battery capacity too large for charger; faulty battery. | Try "Refresh" mode for deeply discharged batteries. Ensure battery capacity is within charger's range (1.2-250 Ah). Test battery condition. |
| Charger automatically stops. | Battery disconnected; power cut; battery fully charged. | Check battery connections. The "Auto Restart" feature should resume charging after a power cut. If battery is full, this is normal operation. |
If the problem persists after attempting these solutions, please contact GYS customer support.
9. Specificaties
| Functie | Detail |
|---|---|
| Merk | GYS |
| Model | GYSFLASH 12.12 (GYS - 029392) |
| Nominaal volumetage | 12V |
| Amptijdperk | 12 Amps |
| Batterijcapaciteit (opladen) | 1.2 Ah tot 250 Ah |
| Batterijcapaciteit (onderhoud) | Tot 330 Ah |
| Compatibele batterijtypen | Lead-acid (WET, MF, Ca/Ca, AGM, GEL, EFB, Start & Stop) |
| Laadcurve | 8-step intelligent charging curve |
| Beschermingsclassificatie | IP65 (Dust and water ingress resistant) |
| Veiligheidsvoorzieningen | Short circuit, polarity reversal, overcharging protection, anti-spark, integrated temperature probe. |
| Afmetingen (LxBxH) | 28x11x5.5cm |
| Gewicht | 950 gram |
| Land van herkomst | Frankrijk |

10. Garantie en ondersteuning
The GYSFLASH 12.12 charger comes with a 2 jaar garantieDe garantie dekt fabricagefouten vanaf de aankoopdatum. Bewaar uw aankoopbewijs voor garantieclaims.
For technical assistance, troubleshooting beyond this manual, or warranty service, please contact GYS customer support through their official website or your local distributor. Provide your product model number (GYSFLASH 12.12 or GYS - 029392) and a detailed description of the issue.
Official GYS Webwebsite: www.gys.fr