Könner & Söhnen KS 48V‑DC direct‑current generator
Overview
The KS 48V‑DC is a compact petrol‑powered generator designed specifically for charging 48 V battery packs. It produces direct current with a nominal output of 3.6 kW and a charging current up to 70–75 A, making it suitable for home energy storage systems, off‑grid solar installations and other applications where reliable battery charging is needed. Unlike conventional AC generators, this unit operates as a charger: it supplies constant current until the battery voltage reaches about 53.5 – 54 V and then switches over to constant‑voltage mode, shutting down automatically when the charge drops below 20 A. The generator has three start options—auto, manual and external—so it can work in autonomous setups without user intervention.
Key features
- Purpose‑built DC output: supplies 48 – 54 V DC for charging batteries rather than running AC tools.
- Constant‑current charging: delivers up to 70–75 A until the battery reaches 53.5 – 54 V, then runs with constant voltage.
- Automatic, manual or external start: in auto mode, the generator starts when battery voltage falls to 47.5 – 48 V and stops when voltage and current reach target levels. Manual starting is possible via a built‑in starter, and an external control terminal allows integration with other equipment.
- Petrol engine: the 223 cm³ KS 240 four‑stroke engine produces 7.5 hp and runs on unleaded automotive petrol. A 12.5 L fuel tank provides about seven hours of runtime at half load.
- Digital display and LED indicators: an LED display shows voltage and current. There are separate LEDs for power (green), overload (red) and low oil (yellow) states, giving clear feedback to the operator.
- Portable design: transport wheels and fold‑down handles make it easy to move the 36.5 kg unit.
- Safety and monitoring: the generator is equipped with overload protection, low‑oil shutdown and IP23M splash protection rating. It is intended solely for charging batteries and must not be connected directly to other loads.
Benefits
- Optimised for energy storage: The KS 48V‑DC is ideal for charging battery banks used in solar, wind or backup power systems. It automatically adjusts to the battery’s state of charge and stops when full, saving fuel and reducing wear.
- Efficient and quiet: With a noise level around 70 dB at 7 m, it is quieter than many portable generators. The constant‑current charging reduces energy waste.
- Easy to operate: Automatic start/stop in response to battery voltage means there is little to no manual intervention. The intuitive control panel with LED display shows essential information at a glance.
- Portable but sturdy: Despite its robust engine and large fuel tank, the generator has a compact footprint (695 × 445 × 445 mm) and integrated wheels and handles for mobility.
Technical specifications
| Specification | Value |
|---|---|
| Model | KS 48V‑DC |
| Output voltage range | 48 – 54 V DC |
| Nominal power | 3.6 kW |
| Maximum charging current | 70 A |
| Starting system | Auto / manual / external |
| Fuel tank capacity | 12.5 L |
| Runtime at 50 % load | Approx. 7 h |
| Display | LED (voltage and amperage) |
| Noise level at 7 m (Lpa/Lwa) | 70/95 dB |
| Engine model | KS 240 |
| Engine displacement | 223 cm³ |
| Engine type | 4‑stroke petrol |
| Engine power | 7.5 hp |
| Oil capacity | 0.6 L |
| Product Dimensions (L×W×H) | 510 х 525 х 310 mm |
| Net weight | 36.5 kg |
| Gross weight | 38 kg |
| Protection class | IP23M |
Operation and maintenance advice
- Before starting, attach the battery pack to the charger and ensure the charging cable is equipped with an 80–100 A fuse. The generator does not contain its own battery and relies on the connected battery for electric start.
- In AUTO mode the unit turns on when the battery voltage drops to 47.5 – 48 V and stops when voltage reaches around 53.5 – 54 V and current drops below 20 A.
- Manual start is possible using the multi‑function rotary selector; the generator will shut down after the charging current falls below 20 A.
- A low oil level will trigger the yellow LED and automatically shut down the engine; check the engine oil before each use and top up with SAE 10W‑30 or 10W‑40 as recommended.
- Use only unleaded automotive petrol with an octane rating of 90 or higher. Do not refuel while the engine is running, and wipe up any spills promptly.
- The generator is intended solely for battery charging and must not be connected to other DC or AC electrical appliances.
Applications
This direct‑current generator is suitable for:
- Charging large 48 V battery banks used in renewable‑energy systems.
- Maintaining battery packs in off‑grid cabins, motorhomes or boats.
- Emergency charging of lithium‑ion or lead‑acid batteries in industrial settings.
Included in the package
- KS 48V‑DC generator unit
- Charging cables with fuse (80–100 A)
- Transport wheels and handles
- Oil dipstick and funnel
- User manual (download full version here)
Notes
This generator is designed to charge batteries; it will not run household appliances or tools. Always operate it outdoors on a level surface and provide at least one metre of clearance around the unit. Keep children and pets away during operation. Failing to follow the manufacturer’s instructions may void the warranty.
Documents available for download
Könner & Söhnen direct-current generator KS 48V-DC user manual