Battery vs diesel tower lights

A worked example: nine hours of lighting per night

Assume a 10 kWh nominal battery with 90% usable capacity powering a total battery-side lighting draw of 1,000 W, with no additional loads. Usable energy is 9 kWh, so estimated runtime is nine hours. This leaves no runtime reserve; a real project should allow for battery age, heat, reserve settings and actual power draw.

The difference is RM670.76 per 30-night month, or about 80.5% of the diesel fuel cost, under these assumptions. This is an energy-only example; no rental, purchase, service or battery replacement costs have been included.

Does a two-hour charge mean two hours of lighting?

No. Charging time and lighting runtime answer different questions. In this example, a nominal 0–100% recharge requires about 11.11 kWh from the grid and costs RM6.03. Delivering that energy in two hours requires about 5.56 kW of average grid power. The charger, battery management system and supply must support it; average power does not describe peak power, current taper or a verified charging time.

After the nine-hour night, replenishing the 9 kWh actually used requires 10 kWh from the grid and costs RM5.43. A full nominal recharge and a normal nightly top-up need not cost the same. Confirm the manufacturer’s charging time and its starting and ending state of charge.

Which Malaysian electricity and diesel rates should you use?

Peninsular Malaysia business electricity

The Energy Commission tariff schedule, effective 1 July 2025 to 31 December 2027, lists low-voltage non-domestic general charges of 27.03 sen/kWh for energy, 8.83 sen/kWh for capacity and 14.82 sen/kWh for the network. Together these are 50.68 sen/kWh, or RM0.5068/kWh. The RM20 monthly retail charge is separate.

Single Buyer reports October 2026 AFA of +3.61 sen/kWh. The calculator and worked example start at RM0.5429/kWh: the RM0.5068 base plus RM0.0361 AFA. This is a dated October snapshot, not a live rate, and excludes taxes, levies, rebates and other account-specific charges.

AFA changes monthly. Replace the calculator rate with the marginal cost of charging on your bill. Allocate fixed charges separately only where the project adds them; an existing account’s entire monthly fixed charge should not automatically be assigned to one light.

For an eligible low-voltage non-domestic Time of Use account, the scheduled components total RM0.5217/kWh at peak and RM0.4808/kWh off-peak, before adjustments. Use the rate for the time you charge, even if the light operates later. Mixed charging periods need a weighted rate. Domestic, medium/high-voltage, Sabah and Sarawak accounts need their own applicable rates; new maximum-demand costs may also matter.

Industrial diesel: use your delivered invoice

Kyusen’s supplied planning range is RM4.50–5.00/L; the calculator uses its midpoint of RM4.75/L. This is an industrial purchasing assumption, not a verified current market quotation. MOF’s weekly retail dataset distinguishes Peninsular and East Malaysia prices. Pump prices, subsidy eligibility and delivered industrial supply terms can differ. Enter your actual eligible delivered price, including relevant delivery costs.

For context, that official dataset lists Peninsular retail diesel at RM5.27/L for 8–14 October 2026. This is a dated retail reference above the supplied industrial range; it does not validate RM4.50–5.00/L as today’s delivered price. The calculator retains Kyusen’s requested industrial assumption until you enter a current quotation.

The following consumption ranges were supplied by Kyusen. They are planning inputs for the referenced diesel equipment, not a universal rating for all tower lights.

Generator engine load is not the same as lamp brightness. Other connected loads, idle operation and equipment condition affect fuel use. Use measured L/hr for your intended lighting setup where available.

Charging efficiency: keep it editable

Manufacturer data illustrates why efficiency must be model-specific: Victron’s IP67 charger specifications list maximum efficiencies of 93–96%, depending on the charger. Those are charger-only maxima, not wall-to-battery performance for Kyusen equipment. The calculator’s 90% wall-to-battery value is an illustrative planning assumption. Replace it with measured grid energy versus energy replenished, or verified whole-system data.

Multi-stage charging includes changing current as the battery approaches full charge. Temperature, supply limits, chemistry, battery size and starting state of charge can change recharge time. A two-hour target must be confirmed against the selected model’s charger and supply requirements.

How the calculator works

Usable battery energy

Nominal kWh × usable capacity % ÷ 100

Runtime in hours

Usable kWh ÷ [(lighting W + additional W) ÷ 1,000]

Charging energy per night

Total draw in kW × lighting hours ÷ charging efficiency

Battery energy cost per night

Charging kWh × electricity price in RM/kWh

Diesel cost per night / month

L/hr × operating hours × RM/L; multiply by operating nights for a month

Simple purchase payback in months

Extra upfront battery cost ÷ (monthly diesel fuel cost − monthly battery energy cost − extra monthly battery costs)

Use charging efficiency as a decimal in the formula: 90% = 0.90. Consumption and runtime are assumed constant, and the battery starts each night charged. The payback result uses midpoint diesel consumption. A zero or negative monthly saving gives no payback, and a runtime shortfall withholds the payback result until an achievable setup and its additional costs are entered.

The cost-neutral electricity rate shows where battery charging energy costs equal diesel fuel costs per night. It excludes upfront and other operating costs. Purchase payback excludes financing and residual value; a rental comparison should instead use the difference between rental quotations in the monthly recurring-cost field.

Choose for your site, not just the lowest energy cost

Equal watts do not guarantee equal light output or coverage. Compare lux at the working area, beam distribution, glare control, lumen output, mast height, wind rating and safe installation. If multiple battery units are needed to replace one diesel tower, include all their power and costs. This calculator compares one unit of each type.

Battery lighting avoids an engine’s exhaust at the point of use while operating on battery power. Grid generation, transport and battery manufacture still have impacts. No carbon reduction, noise level or lifetime claim is calculated here. Charging from a diesel generator needs its actual delivered electricity cost, including losses and generator fuel use.

Sources and assumption notes

Checked on 8 October 2026. Tariffs and fuel prices can change; verify the current bill and supplier invoice before making a project decision. Equipment examples are editable and no verified KMC500 or HRZ322 specifications have been assigned.

• Energy Commission: Peninsular electricity tariff schedule — effective 1 July 2025–31 December 2027; low-voltage non-domestic general and ToU.
• PETRA / myTNB: Automatic Fuel Adjustment — monthly adjustment mechanism for Peninsular Malaysia.
• Ministry of Finance / data.gov.my: petroleum and diesel prices — weekly retail reference; not a delivered industrial fuel quotation.
• Victron Energy: Blue Smart IP67 charger specifications — manufacturer example of charger maximum efficiency; not a Kyusen charger specification.
• Victron Energy: charging operation — charging stages and current taper; not a two-hour tower-light claim.
• Single Buyer: October 2026 Automatic Fuel Adjustment — October 2026 surcharge of 3.61 sen/kWh; dated snapshot, changes monthly.

Diesel consumption and industrial fuel-price range: supplied by Kyusen for this guide. No public manufacturer datasheet was supplied for those consumption figures. Calculated results are estimates and do not guarantee equipment performance or savings.