How To Use A Battery Tender on a Motorcycle


Many bikers live in areas where all-year-round biking is either impossible or just not fun. If you live in a place like this, you probably put your bike away for the winter months. Or perhaps you can only use your bike now and then.

A bike that stands unused for a while can deteriorate, and your battery is one of the quickest parts to fail. A battery tender is a handy bit of kit to keep your battery in tip-top condition.

Read: How often should I start my motorcycle

What is a battery tender?

A battery tender is a type of battery charger with added functions. Basic battery chargers are designed to provide a high current at the start of the charge, and as the voltage level increases, the supplied current automatically reduces. 

battery tender

This reduction in current is caused as the battery becomes fully charged, but crucially, the current will never drop to zero. This means that leaving a standard battery charger attached to your battery will eventually damage the battery.

A battery tender has built-in electronics that control the current supplied so you can leave it connected to your battery. 

Why should you use a battery tender?

A battery tender is an essential piece of kit if you tend to leave your bike unused for extended periods. If you have an alarm fitted, it’s even more critical.

Using a battery tender will keep your battery at the correct charge, so your bike will always start. In addition, a tender will prolong the life of your battery, saving you money in the long run.

Read: How long do motorcycle batteries last

How to use a battery tender

While Battery Tender is a specific brand name, there are other manufacturers out there, so do check out others such as TecMate, and the Oxford Optimiser

With just a few exceptions, battery tenders all work similarly. Some more expensive models will offer additional features, but the basic process is as follows;

battery tender
  • As with any battery charger, there are some precautions to take. Acid batteries produce explosive gasses, and short-circuiting a battery is not a good idea! To avoid any problems, follow these simple rules;
    • Work in a well-ventilated area
    • Locate the charger as far away from the battery as possible
    • Do not connect the battery tender to the mains outlet yet
    • Make sure the charger is switched off
    • Make sure the chargers connectors cannot accidentally touch each other
    • Don’t let the chargers cables touch the metal bodywork or frame of the motorcycle
    • At the risk of sounding like a crazy health and safety guy, wearing gloves and eye protection is recommended
  • Connect the red charging cable to the red (positive) terminal of your battery
  • Connect the black charging cable to an earth point on the bike as far from the battery as possible. Connecting this cable is when you will get a spark that could ignite battery gasses
  • Plug your battery charger into the mains outlet
  • Select the charging mode you want. This will vary from model to model, so check the manual. Many have an auto mode.
  • Let your battery tender work its magic!
battery tender

Additional features

Permanent charging cable

Attaching a permanent charging cable to your battery is a great idea. It makes connecting your battery tender a simple plug-in job and removes the potential of sparks igniting the battery gasses.

Once you have connected the cable to your battery, you can put the connector somewhere convenient, such as under your seat.

Different modes

While some battery tenders simply keep your battery at the optimum charge level, many offer different modes designed to recover deeply discharged batteries.

Unlike traditional battery chargers, tenders are microprocessor controlled, allowing them to sense the battery condition and adjust the charging method accordingly.

In most cases, the automatic mode is fine, but you may need to override this if the battery is completely flat.

Read: How long does it take to charge a motorcycle battery

Wall mounting

Most battery tenders come with a wall mounting system, perfect for keeping the charger handy and reminding you to connect it! 

Lithium Batteries

Note if your motorcycle has a newer style Lithium-ion battery, you will need to use a special lithium battery charger.

Read: Types of motorcycle batteries


battery tender

Using a battery tender is much the same as using a traditional charger but with additional features and benefits. Your battery will be happy, and so will your wallet!