Modern motorcycles rely heavily on their electrical systems for their fundamental functioning.
While electricity is essential on ECU-powered fuel-injected bikes, any motorcycle with a headlight, backlit-instrument display, and electric starter requires battery current for healthy operation.
This article lists the most common reasons a motorcycle loses electrical power while riding.
1. Test your Regulator/Rectifier
Motorcycles works with a charging system responsible for recharging your battery while you ride. The system does this by converting the AC generated by your bike’s motor into DC your battery can use.
It’s called a Regulator/Rectifier because it regulates the battery’s current by rectifying the AC into DC.
If your motorcycle’s Regulator/Rectifier or R/R is faulty, your bike’s battery loses its means of recharging while you ride.
Since running your lights and electronics depletes your battery’s charge, a lousy R/R can cause your bike to lose electricity in the middle of your ride.
And that’s not all; since the R/R is also responsible for the charging regulation, a faulty R/R can fail to regulate the charge and prevent overcharging, causing your battery to explode while you’re riding.
Even if it’s only its rectifying function that’s failing to convert the AC to DC, the battery can’t store the electrical current. Instead, it’ll kill your bike’s battery power while the cycle is in use.
To learn more about this, check 11 reasons your motorcycle battery won’t charge while riding here.
2. Inspect Your Stator
Your motorcycle’s stator is the other half of your bike’s charging system. It has a more straightforward function than the Regulator/Rectifier described in the previous section.
The stator’s job is to harness the engine power for the R/R to convert into battery charge, making it an early troubleshooting step on a motorcycle that loses electricity while the bike is being ridden.
- Your stator has consistent flows of energy passing through it at all times.
- Furthermore, the stator is located inside your bike and is thus exposed to high levels of engine heat.
- Like all motorcycle components, stators wear out eventually.
- Once your bike’s stator is worn out, it fails to provide the constant power supply your battery requires to power your electrical system while you ride.
If a faulty stator is why your motorcycle loses its electrical charge while in motion, the only real fix is to replace the bad stator with a new one, preferably one recommended by your motorcycle manufacturer.
3. Tighten Battery Cable Connections
One of the most typical and easily fixable reasons a motorcycle loses electricity while riding is because of an unstable or insufficient battery terminal connection.
The terminals are the two small metal pieces that stick out from either side of the motorcycle’s battery. If a motorcycle has a flawed connection between the battery cables and terminals, your battery won’t recharge as it should.
This is because the components of the charging system described above replenish the battery through these cables.
If your bike is losing power due to loose battery cables, you’re in luck, as this is quite possibly the most manageable problem to resolve on a motorcycle.
Tighten the charging cables to spec with a few quarter-inch turns of a wrench or screwdriver to restore your battery’s charging ability and prevent your bike from losing power while in motion.
4. Clean Corroded Battery Terminals
Another issue that makes a motorcycle to lose electricity while riding is corroded battery terminals. Corrupted terminals prevent the battery from accepting the recharge current. This is similar to loose battery cable connectors.
- Exposure to moisture or other corrosive riding conditions like salinated air can cause rust to form on your battery terminals.
- The rust acts as a buffer between the battery terminals and the cable the stator uses to recharge it while you ride.
- Once the battery’s charge is depleted, your motorcycle will lose electricity and shut off during your ride.
Moreover, if the corrosion buildup on your terminals is light, you might be able to salvage the battery by removing the battery from the bike and scrubbing it free of rust. Do this by following the safest procedures you can find published online.
Mind you, if the corrosion is severe enough, you may need to replace the battery to keep your bike from dying.
5. Replace Dead, Incorrectly-Sized, or Sulfated Battery
Another common cause of a motorcycle losing electricity while riding is a dead battery.
The lifespan of a motorcycle’s battery is typically between two and four years. That said, overworked batteries fail sooner due to extreme temperatures, the draw of accessories, and poor electronic groundings.
- Once a battery wears out, it loses its ability to hold a charge, meaning that while you’re cranking your throttle, your battery is losing its charge.
- It’s only a matter of time before a dead battery loses its charge, causing your bike’s electricity to shut off while riding.
Another common cause of power loss on a motorcycle is battery sulfation – the buildup of battery acid crystals.
The crystalized battery acid blocks the terminal from replenishing during use, just like the rut described in the previous section.
A sulfated battery not only prevents the battery from charging while you’re riding the motorcycle, but it also results in power loss and dips in engine performance.
You might notice your battery is completely dead after a long rip, or it could just be that you’re seeing longer charging times. Either way, sulfation will absolutely interfere with your bike battery’s charging process.
And finally, if you’ve got the incorrect battery size in your motorcycle, it’ll cause interference with the charging process, which could lead to electrical failure while you’re riding the bike.
- Motorcycle batteries come in different sizes and are manufactured from other materials.
- Consult your bike’s owner’s manual to determine precisely what type of battery your bike requires for healthy operation.
If you’re running extra electronic equipment, you might need to go up a size in the battery. So, consult a mechanic who’s experienced with electrical repairs on your bike’s make and model to find out how to increase your battery power.
Doing this could help to stop your bike from shutting off while under heavy electrical load. You may want to read about why a motorcycle loses power at high RPM here.
6. Reinstall Aftermarket Add-Ons
Let’s assume your motorcycle is re-installed with aftermarket add-ons like LED fog lights or headlights, heated grips or seats, speaker enhancements, or LED underflow. In that case, your motorcycle may be drawing more power than your battery is equipped for.
In some cases, these aftermarket accessories work together to drain your bike’s battery faster than your R/R and Stator can replenish its charge, making the motorcycle lose electricity while riding.
In other case, the add-ons were installed by snipping the wires and meshing the accessory into the wiring harness with inadequate solder or electrical tape. This exposes the copper and causes a short course.
Regardless, you’ll need to reinstall the poorly-connected accessories, or the bike will continue to lose power while you ride, even after you recharge the battery.
7. Reduce Electrical Draw
Many of the components of modern motos are electrically powered. As such, they are managed and timed by the bike’s Electronic Computer Unit.
If one of these components gets stuck or hiccups intermittently, it draws more electricity to get through the lag.
If a jammed motorcycle part pulls an excessive load of electricity to power through its failure, the change in the current can cause electrical loss. This can short-outs, blow fuses, and cause your bike to lose power while you ride.
Here are a few components that can have problems and result in a power draw that could be excessive enough to blow a fuse:
- Fuel Pump
- Fuel injection or onboard timing CPUs
- Ignition Coil
- Display Gauges
- Starter Relay
- Ignition Switch
If a faulty part is drawing excessive battery current, you’ll need to replace the part to prevent your bike from losing electricity while in motion.
8. Inspect Ground Wire for Shorts
A short in your motorcycle’s ground wire is a complex problem to pinpoint. But, it’s one of the most common reasons a motorcycle loses electricity while riding.
A faulty wire ground on a motorcycle causes intermittent electrical failure throughout the machine’s wiring harness and electronic parts.
These problems can draw more power from your battery as they worsen, leading to a bike that loses power while riding.
- Your motorcycle’s wire circuitry warms and cools continuously throughout use, causing its casing to wear out over time.
- Once worn past a point, the rubber coating splits open, exposing the copper inside the wires’ connectors.
If the connector touches a conductive object, like the metal frame, engine, or gas tank, the electricity escapes from your stator or battery circuit via the wire split. While this could ride the frame metal into the earth, it could also make your motorcycle to lose power while riding.
- If worn or cracked ground wires are why your bike battery loses electricity while riding, consult your owner’s manual and examine the condition of all your grounds.
- If a short in a ground wire stops your battery from charging while you ride, replacing the damaged wire is the surest solution.
Fortunately, a wire replacement is an easy, inexpensive fix for any decent motorcycle mechanic.
9. Inspect Ignition Switch
If your ignition switch is faulty or develops a short in its wiring, it will try to pull extra electricity from the battery into its circuit.
If your ignition switch wears out, as all ignition switches do eventually, it may attempt to pull so much electricity that kills the battery and powers your bike down.
- A motorcycle ignition switch is typically hooked into the starter circuit.
- If a faulty ignition switch is why your bike loses electricity while you’re riding, your starter fuses will repeatedly blow until the ignition switch’s short is repaired or the button itself is replaced.
That said, you must replace frayed motorcycle wires immediately, especially if they’re causing shorts in the starter circuit.
Not only can a sudden power loss while riding cause a motorcycle collision, but a faulty ignition switch can also kill your starter system and leave you stranded.
10. Check Your Fuses
Some motorcycle engineers run numerous circuits off of the same fuse. Since modern bikes equip more complex electrical systems, most wiring harnesses stock a separate fuse for each electrical circuit.
Replacing the incorrect fuse on your motorcycle can cause your bike to lose electrical power, as there’s still a faulty circuit in your motorcycle without a fuse to protect it.
Another common problem leading to electrical failure while riding a motorcycle is replacing a blown fuse with a fuse of a different rating than specified for that particular circuit.
Here are the standard fuse ratings used on most bikes:
- 5 Amps
- 10 Amps
- 15 Amps
- 20 Amps
- 30 Amps
If the circuit uses a 15 Amp fuse, it will blow once 15 amps of current enter the circuit. If the circuit needs 20 amps, the fuse will blow before it builds up its usual power.
That said, if a part in the circuit can only 10 amps of current before it fries, but you install a 20 AMP fuse, the fuse will let up to 10 extra amps into the circuit before it blow.
To learn more about this, check out our post on what to do when your motorcycle keeps blowing its fuses.