50KW Yuchai Diesel Genset + Maintenance-Free Battery: Specs & Service Plan
50KW Yuchai Diesel Generator + SWG Maintenance-Free Battery: A Practical Backup Power Guide
When a small factory, farm cold-room, or off-grid worksite loses grid power, the difference between a 10-minute hiccup and a 10-hour shutdown usually comes down to two things: a genset that actually starts, and a battery that hasn’t quietly died during standby.
For sub-100KW backup duty, the Yuchai 50KW diesel generator set paired with the SWG 6-FNM-930G maintenance-free starting battery is one of the most cost-effective combinations we specify for clients across Africa, Southeast Asia, and Latin America.
Why 50KW? Sizing for Real-World Loads
A 50KW prime / 55KW standby unit (62.5KVA rated, cosφ 0.8) hits the sweet spot for small to medium operations:
- Small manufacturing workshops: cutting machines, air compressors, lighting circuits
- Livestock & aquaculture: aerators, feed grinders, cold-chain storage rooms
- Construction sites: site offices, batching plants, small power tools
- Healthcare facilities: clinic lighting, vaccine refrigerators, ICU support fans (non-OT)
- Infrastructure: rural telecom shelters, water pumping stations
Yuchai 50KW Genset: Core Configuration
Built on the proven Yuchai YC4D90-D34 platform (typical 50GF class), this unit balances fuel efficiency with robust power delivery.
| Specification | Details |
|---|---|
| Engine | Yuchai YC4D90-D34, 4-cyl, turbocharged, water-cooled, 1500rpm |
| Prime / Standby | 50KW / 55KW |
| Voltage | 400/230V, 3-phase 4-wire, 50Hz |
| Rated Current | 90A |
| Starting System | 24V DC electric start |
| Alternator | Brushless, AVR, Class H insulation, IP21/IP23 |
| Fuel Consumption | ~205 g/kWh (≈8.2 L/h at full load) |
| Control Panel | AMF/LCD, auto start/stop, overload & low-oil protection |
| Dimensions (Open) | ~1830 × 750 × 1100 mm |
| Weight | ~900 kg |
Yuchai’s non-road T3 combustion tuning ensures low fuel burn and stable frequency recovery (<5 seconds)—critical when running grinders or submersible pumps with high inrush currents.
The Missing Link: SWG 6-FNM-930G Maintenance-Free Battery
A diesel engine is only as reliable as its cranking battery. The SWG 6-FNM-930G sealed lead-acid battery is our default specification for 30–100KW units.
Key Advantages:
- Zero Maintenance: No distilled-water topping throughout its service life.
- Low Self-Discharge: Survives 3–4 weeks of idle time in humid tropical climates.
- High CCA Rating: Ensures confident cold and early-morning starts.
- Safe Handling: Corrosion-resistant terminals, pre-filled electrolyte, no on-site acid handling.
Maintenance Tip: Even maintenance-free batteries require care. Run a standby genset for 10–15 minutes weekly (no-load). Ensure the built-in battery charger stays on float charge from the grid or solar input. Replace the battery every 18–24 months if cranking sounds sluggish.
Recommended Maintenance Schedule (Yuchai 50KW)
Follow the rule: "Running Hours OR Calendar Time—Whichever Comes First." Standby units age on the clock, not just the hour meter.
| Interval | Task |
|---|---|
| Daily / Pre-start | Check oil level, coolant, fuel level, battery voltage, and leaks. |
| First 50 Hours | Replace engine oil and oil filter (critical break-in service). |
| Every 250 Hours / 6 Months | Replace engine oil, oil filter, fuel filter; drain fuel tank sediment. |
| Every 300 Hours | Inspect/replace air filter (reduce to 100–150h in dusty environments). |
| Every 500 Hours / 1 Year | Replace coolant, clean radiator fins, check belt tension. |
| Every 1000–1500 Hours | Inspect valve lash, injectors, and turbocharger. |
| Standby Idle Rule | Monthly 5–10 min no-load run; quarterly battery voltage check. |
Oil Recommendation: Use 15W-40 CF-4 above 0°C; switch to 5W-30 in colder regions. Never mix oil brands.
Total Cost of Ownership (TCO) Perspective
With an ex-works price of approximately RMB 24,000 (USD 3,300–3,600)—depending on alternator brand and whether a silent canopy is specified—the Yuchai 50KW is not the cheapest listing online. However, the TCO tells a different story:
- Fuel Savings: 10–15% lower consumption compared to older second-hand units. On a 6-hour nightly run, this pays for the battery and first-year oil changes in roughly 8 months.
- Downtime Prevention: One spoilage incident in a cold-room or a missed water-pumping schedule often exceeds the entire battery budget.
- Parts Availability: Yuchai parts are stocked in most African capital cities, eliminating the risk of a 6-week wait for a simple gasket.
Conclusion: Reliable Power Is More Than a Nameplate
If you need a 50KW-class backup that starts on the first crank and doesn’t bankrupt you on service, specify:
- Yuchai YC4D90-D34 50KW Genset (open or silent), 24V start, brushless alternator.
- SWG 6-FNM-930G Maintenance-Free Battery (or equivalent 24V sealed pack).
Power isn’t just about the nameplate rating. It’s about the third time the grid drops this month—and the machine still turns over.
For checking suitable generator product for your project— Contact NovArk Power
Get a free power system design consultation for your diesel generator set project. Our engineers will analyze your requirements and deliver a tailored generator solution.
This article is for informational purposes only. Specifications and availability may vary by region. Please contact NovArk Power for a confirmed quotation tailored to your project requirements.


