Alternator
Produces raw AC power as the engine spins. Output rises and falls with RPM.
220WLuxFit · Free tool by Lumevo
Your motorcycle already picked your fog light.
Riders shop for auxiliary lights by watts — more watts, more light, done. But watts were never the thing that decides. Your alternator is. LuxFit shows you exactly how much power your bike has spare, then names the light that fits inside it.
5Steps
~2Minutes
FreeNo signup
18Makes covered
The problem
Where the power actually comes from
What most riders assume “The battery runs my lights.”
So any light gets fitted, and the bike is expected to cope.
What actually happens The engine runs your lights.
The battery only stores charge for starting and buffer. Everything you switch on is drawn from the alternator, while it is also feeding the bike.
Regulator / rectifier
Converts AC to DC and caps the system at 14–15V. Burns off what it cannot use as heat.
14–15VThe bike takes its cut
Headlight, ECU, ignition, indicators, horn and charging all draw first — before you add anything.
−110WWhat is left for you
This — not the wattage printed on the box — is your real ceiling for auxiliary lights.
110WRead that last number again. A rider fitting a “more is better” 150W bar to this bike is asking for 40W the machine cannot produce — every ride, at every RPM.
High-watt fog lights
Drain systems faster than charge recovery allows.
Regulators overheat
Excessive load causes thermal runaway in circuitry.
Stators wear out
Coil insulation degrades under heavy current stress.
Voltage drops
System instability occurs at high engine RPM.
The solution
LuxFit turns that ceiling into one number
Your watt budget
Example: Royal Enfield Classic 350 · 2024 Alternator output — 220W total Safe ceiling for a light: 99W
Bike’s own load · 110W
Your light · 90W
Load status Safe
Fits with 9W to spare. This is what LuxFit recommends for this bike.
Alternator220W
Bike uses110W
Your light90W
Margin left9W
The output
You leave with a report card, not a guess
Electrical health analysis
- Motorcycle
- RE Classic 350 · 2024
- Alternator output
- 220W
- Existing load
- 110W
- Recommended light
- X2 Plus · 90W
- Safe margin
- 9W
- Load status
- Safe
And the reasoning behind it
- Matched to how you rideFog frequency, cruising speed and terrain all shift the recommendation.
- Full technical specLux output, colour temperature, IP rating, housing, voltage range and lifespan.
- Saveable and shareableKeep the report, or send it to your mechanic before anything gets wired in.
- Bike not listed? Say soMissing models and wrong figures can be reported from inside the tool.
How it runs
Four stages, about two minutes
- 01
See the flow
A plain walkthrough of how your bike makes and spends power.
- 02
Pick your bike
Make, model and year — plus anything you have already wired in.
- 03
Say how you ride
Fog, speed, terrain and whether you wear glasses for far vision.
- 04
Get your report
Your matched light, full specs, and a report card you can save or share.
Every Lumevo light is built to sit inside a real bike’s budget, not above it. Find yours before you buy — no signup, nothing to install.
Figures shown are a live LuxFit result for a 2024 Royal Enfield Classic 350, used here as a worked example. LuxFit holds back an 11W reserve so voltage stays stable at low RPM. Your own bike’s numbers will differ — run the tool to see them.
