Why Does My Motorcycle Battery Die/Drain So Fast?

Why do motorcycle batteries die So Fast? Generally, a motorcycle battery lasts for about two years, provided the motorcycle is not parked for longer periods unused. The battery will also drain or die faster if periodic servicing is not done.

Why do motorcycle batteries die So Fast

A well-maintained motorcycle battery lasts longer, especially if there’s no manufacturing defect in the battery.


Most of the time, a dying motorcycle battery drains faster. It is mostly be caused by a charging problem or unusual drain. Excessive idling and parking the motorcycle for too long can also kill your motorcycle battery faster. Meanwhile, below are the reasons why your motorcycle battery dies so fast:

Accessory Wiring Problem

If battery problems started after you recently added accessories, such as a phone charger and radio, to the bike, they could be the culprit.


If the additional components require the electrical system connection, begin your investigation in the accessory wiring. You may also disconnect non-stock motorcycle components to check whether your bike battery holds the charge.

However, if all accessories are wired/connected properly, and the charging system is functional, consider other possible causes.

Not Using Battery Tender

Experts recommend using battery tender if you don’t ride your motorcycle at least an hour weekly. Simply install the battery tender and plug it in after parking your motorcycle.

A new battery tender may cost around the price of a new battery. However, it keeps you from having dead batteries that require frequent replacements.


Charging Fault

The motorcycle charging system may be unable to produce enough power to charge the battery. So, the battery will lose its charge faster than necessary.

The alternator, an electrical generator, converts mechanical energy to electrical energy by alternating current, which charges a motorcycle battery. If you suspect the alternator, have a mechanic check it.

Wiring Harness Connector

The wiring harness connectors can also cause a motorcycle battery to die fast. Wiring harness connectors typically heat up and melt or come loose, causing poor or no connection.

Make sure to inspect the wirings and be attentive to the plastic connectors. Moreover, endeavor to check that the battery terminals are not heavily corroded. Corrosion on terminals can prevent charging.

Read also: causes and solutions for popping sound when accelerating bike

If the wiring is OK, inspect the rectifier/regulator using a basic multimeter. Using any search engine, including Google, Bing, Yahoo, etc., search “how to check your stator for [name of motorcycle]”. There’d be an Ohms resistance and an AC voltage check when the motorcycle engine is running. You may refer to helpful YouTube tutorials. Search “how to check voltage regulator for [name of bike]”.

System Drain

There could be a constant drain on the system that makes the motorcycle battery die fast. Typically, wiring assembly or any combination switch assembly could be faulty. Even a faulty short circuit could be the culprit behind your bike battery dying so fast.

Dying Cell

If you use an ordinary wet cell battery, it may be approaching the end of its useable life. Most modern batteries last around two years. So, if you’ve reached this number of years, you’d be experiencing draining faults.

DIY Tip to Tell Why Motorcycle Battery Dies Fast

First, remove the battery from the motorcycle and bench-charge it overnight, and make sure to replace it with only + lead.

Set the voltmeter to 20VDC between negative and negative lead. Turn off all loads. If there is any voltage, take off fuses. Remove just one at a time until the voltage goes off. Don’t take off big mains one in for now. The last one is your battery drain; check the manual to know where it goes.

Check misadjusted or bad brake light switches, and side stand/clutch lockout switches by unplugging switches.

If you find voltage, take off mains fuse. If there is no volt now, you have to replace the regulator/rectifier.

However, if you have no voltage, you have no battery drains. Enable sickle charge. Check the charge voltage at 1200 RPM or thereabout. If it is lower than 13.6 to 14.4 with hi beams on, the connections or regulator/rectifier is faulty.

If it feels warm, it may be working right. Ensure to check and tighten the battery connections and grounds.

If nothing happens after following the steps above, your motorcycle battery is bad and requires replacement.

Alternative Expert Advice

Get a multimeter and check whether battery voltage measures up to 12.5 at least. When you switch on the motorcycle, the voltage will drop and then rise a bit when you start the engine.

Rev the engine up to 1/3 revs volts and the voltage should rise between 13.8 and 14.5 volts. Otherwise, the charging system is faulty may have to follow the owner’s manual to repair it or contact the mechanic.

Final Thoughts

Motorcycle batteries die so fast for the various reasons mentioned in this article. Always be watchful of the grounds because they are important in the charging system.

Corrosions and broken wires inside insulation are common causes why your battery would not charge, and so it drains/dies faster. Make sure to clean suspicious connections to get rid of poor connectivity. Finally, get a new motorcycle battery if your current battery is older than 2/3 years. In emergent situations, you may bump start your motorcycle or kickstart/push start it. Alternatively, you can start your motorcycle using a car battery, but do not make it a habit.

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