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You have a weak motorcycle battery but you have managed to continue riding almost as usual because you just jumps start it whenever you need to. Will doing this have any negative effect on other parts or overall performance? Does a battery affect motorcycle performance?

What happens when the battery in your motorcycle is weak or dead?  Should you still ride the bike? Is performance affected?

Yes and no. There is no clear-cut answer to this one. We can say that a bad battery has no direct effect on the performance of your motorcycle but if we look at indirect effects, then yes, a bad battery definitely can contribute to poor performance.

Role of Motorcycle Battery

The battery in your motorcycle has 3 roles. The first and most significant is to provide sufficient current to start the engine. When you push the start button, it is the battery which channels current to the starter, ignition and fuel system to get the engine running.

After the engine is started and the bike starts moving, the alternator takes over. It provides required power to the engine and also charges the battery to replenish the power used to start up the engine.

The other role is to provide supplementary current when the bike requires more than the alternator is able to provide. This typically happens at low rpm (revolutions per minute) and electrical demand is high. It could happen when you are stuck in traffic with the lights, stereo and perhaps GPS on.

A third function of the battery is a voltage buffer. It acts as a buffer between the charging system and electrical components.

The alternator is capable of producing fairly high voltages which if left unchecked could fry the components. The battery therefore serves to regulate voltage from the alternator in the event of dangerous spikes.

Does a Battery Affect Motorcycle Performance?

Motorcycle Performance

With the basic functions of the battery in mind we can conclude that a bad battery doesn’t have a direct effect on the performance of the motorcycle. Its primary role is to start the engine.

Once the engine is started, the bike will work just fine even if the battery is weak. If the battery is dead, there is the option to use jumper cables to start it and be on your way… bad battery or not.

On the other hand, it would be wrong to assume that all will be well if the battery is weak or dead. There are several indirect effects of a bad battery on a motorcycle’s performance.

These are some of them:

Indirect effects of a bad battery

Strained Alternator

As mentioned, the battery’s role is to supply current to start the engine. After that it hands over to the alternator which supplies current and also charges the battery until it is fully charged. Getting the battery back to full charge usually takes only a few minutes.

If the battery is weak, the alternator charges the battery as usual but continues to do so because it never achieves full charge. This puts unnecessary strain on the alternator.

Alternators are not built to run on full capacity all the time. They are designed to supply initial high current to replenish what was spent then taper supply. A weak battery forces the alternator to run on full output as long as you are riding. This causes it to overheat and eventually kills it.

 Decreased Fuel Economy

A weak battery does have an indirect effect on your pocket where gas is concerned.  As long as the battery is weak, fuel injectors struggle to add fuel to the cylinders as efficiently as they should. With this, you are likely to notice that you need more fuel than you usually do to cover the same distances.

Weak batteries could also cause reduced efficiency of oxygen sensors and sensors used to detect other gases. When these sensors fail, the computer cannot accurately measure the rate of exhaust fume production. When this happens more fuel is consumed and lost through the exhaust.


When battery voltage is low, the starter struggles to do its job and begins to overheat. With time, cables, terminals and other adjacent parts also overheat and could get damaged.

As battery voltage drops, current draw rises. The higher the current draw the higher temperatures rise.  If nothing is done, the vicious cycle continues and the cumulative effect eventually affects overall performance of the motorcycle.

Poor performance of accessorie

The classic symptom of a weak battery in a car is dim lights. The same goes for you motorcycle. When the battery is not producing enough current, lights and accessories like the clock and stereo system fail. Lights may be dim or may fail completely.

If the battery died and you had to jump start it, any settings in any of the accessories will be lost. This is especially inconvenient if you have a GPS system.

Motorcycle Battery Maintenance

Motorcycle Battery Maintenance

The average lifespan of a motorcycle battery is 5 years.  How long it lasts has to do with the quality of the battery but a lot more to do with how well you maintain it.

There are some maintenance practices you can take up to avoid dealing with weak batteries and replacing dead ones every year. Some take no more than a few seconds of glancing through while others require a little work.

Visual Inspection of battery: Make a point to visually inspect the battery at least once a month. Check that there are no bulges on its body and the terminals are properly connected.

Clean corrosion off terminals: Don’t be surprised if you notice a white powder like substance collecting around the terminals. It is not a sign of a problem with the battery but it does mean that the battery is overdue for cleaning. Be careful not to touch it with your bare hands.

To clean it off, remove the cables and scrub it off using a stiff brush and baking soda. If this is not done, continuous build up can corrode the terminals and cause the battery to fail.

Check terminal connections: This can be done as you clean the terminals. Most cables are attached using a screw clamp. If any of the connections are lose you may experience intermittent failure of the starter or total failure.

Top off lead-acid batteries

The electrolyte in these batteries gradually reduces as it gets older. Make a point to check the levels every month. If the levels have dropped significantly, add some distilled water up to the minimum marker point on the side of the battery.

Don’t use tap water because it contains chemicals which could damage the battery. Also avoid adding sulphuric acid because the concentration of acid is still as required, only that it has lost water.

Attach a battery tender

If you will be away on vacation for several weeks or just won’t be taking any rides because it’s freezing outside, don’t let you battery discharge itself to death.  Use a battery tender. Although you can always come back and jump start it, this shortens its life span every time you do it.

Attach a battery tender for the period you will be away. It continues to charge the battery and ensures that it doesn’t die.


It is thanks to the battery that you can quickly start the engine whenever you press the start button. What happens if there is something wrong with it? Does a battery affect motorcycle performance?

It may not have a direct effect on the bike’s performance because the bike will run fine after the engine is started. However, there are several indirect effects which make riding a bike with a weak battery a bad idea.

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