Nine steps to a happy battery
Your battery’s health can suffer for many reasons, but prolonged periods of non-use will do the most damage. Alarms and GPS trackers create a drain and will often hasten a battery’s demise. If you suspect your battery has been compromised, first check the voltage with a multimeter, making sure the dial is on the correct scale. A healthy battery should show between 12.55 and 12.95 volts with the ignition off.
2How’s the charging system?
If you find your battery voltage is low, the next step is to perform a voltage check with the engine running. Using the same scale as before the battery should be measuring 13.5-14.7v. If you discover that it’s reading lower than when the engine wasn’t running then you may have a charging problem. Check in your bike’s workshop manual for details of the specific charging outputs.
3Get some juice back in the battery
If the battery is reading low, connect a charger. Make sure the battery is taking charge by checking the voltage with a multimeter. If it is taking charge, the voltage should be 13.5v to 14.5v. If the battery is heavily discharged it’s possible that the charger, especially if it’s a microprocessor type, won’t recognise it – but all might not be lost as we’ll explain in step four.
4Call in some reinforcements
It’s possible to boost a heavily discharged battery by connecting it to one from a car or bike using jump leads. Be sure to connect positive to positive and negative to negative. Use a meter to check the voltage of your bike’s battery, it should recover fast if the battery is in good condition. After 30 mins disconnect the leads and re-check the voltage.
6Lead acid battery still struggling?
If the voltage is still suspect, use a hydrometer to test each cell. The hydrometer scale should read the same for each cell, any reading that is less than the others will indicate that the cell is in decline. The translucent battery case will let you see if lead sulphate crystals are forming on the plates – in both cases the battery is on the way out.
8Know your chargers
There’s a bewildering range of chargers, each suited specifically to the needs of different types of batteries, so it’s important to know what type of charger you are using. A traditional charger will boost a battery faster than a microprocessor-controlled ‘smart’ charger. But these older, more basic chargers are not suitable for being left connected to a battery 24/ 7. Always check the specs and type of charger you are using.
Most modern batteries are sealed but older bikes using lead acid batteries may need a bit of routine care. The acid levels in this type of battery go down over time so will need regular topping up. Charge the battery in a well ventilated area with the caps removed. Then, once charged, top up the levels to the indicator mark using deionised water.
7Prevention is better than cure
In order to keep your battery in tip-top condition, consider fitting a remote charging lead. This easily allows a charger to be connected when the bike is not in use. Most of the microprocessor/smart type of chargers come with a cable that semi-permanently connects to the battery but can be discretely tucked out of the way when not in use.
9Grease your terminals
Always make sure the battery is clean and not contaminated with layers of road grime, so if it’s looking a bit worse for wear, give it a wipe down with a clean cloth. Refit the connectors and grease the terminals lightly, using dielectric grease. Make sure the fasteners are tight and secure. Any ventilation hoses should be fitted, and checked for kinks and correct routing.