Treating your bike’s battery right.

Most motorcycle batteries are hidden away out of sight.

We never think of them and often don’t even consider that they are a component that calls for any type of regular maintenance or checks. Then, when out of the blue they fail to whip the bike into instant life, we fly into a rage and start tearing bits off the bike, searching for the battery while shouting in a sweaty rage “Battery! You had ONE job, dammit!”

Batteries are silent achievers, often ignored. So let’s take a look at some battery facts and get to know them a bit better.

A brief background on batteries
For decades, motorcycle batteries were much like car batteries, but smaller. That is to say, a series of metal (usually lead alloy) plates separated by spacers, bathed in a lovely corrosive electrolyte in order to generate enough current to run the bike’s electrical systems. Despite being big and heavy by today’s standards, motorcycle batteries in your grandpa’s day didn’t really have all that much to do. Bikes were often fired up by kick-starting and fed fuel by carburetors rather than electrically-powered injectors. Life was simple and batteries had it relatively easy. 

Then…modern sports bikes happened. Superbikes evolved quickly. Suddenly kick-starting was almost extinct, fuel injectors replaced carbies and bike manufacturers became obsessed with keeping every component small, light and tucked away.

Of course ‘light’ is a bit of a stretch when you are made mostly of lead, and ‘small’ is at odds with packing enough power to start and run, say, a high-compression 1,000cc engine. Or perhaps an adventure bike with every conceivable electric accessory from spotlights to GPS. And so we find ourselves where we are today, riding bikes that feature batteries often just barely big enough to do the job. Batteries that demand a bit of TLC in order to keep delivering the goods.

So where is my battery and how should it look?
Seriously? You don’t even know where it is? Okay, no biggie, generally its location is included in your owner’s manual. And in the vast majority of cases, your battery will live under your bike’s seat, so if you can remove your seat, you can find the battery.

So how’s it looking under there? It should be tucked into its tray or box, sometimes held down with a strap or bracket. There should be plastic or rubber covers over the terminal connections, one of which is usually black (negative) and the other red – (positive). There should be no corrosion on the terminals – keep them clean. The battery shouldn’t be able to move around or rattle in place. Its plastic case should be in good condition and there should be no leaks. 

So now that we’ve established that your battery is a boring plastic box with no moving parts, how do we know it’ll do its job when you need it, and what’s the ‘right’ way to treat a battery to keep it performing for as long as possible?

Can I check my battery’s health?
Yes you can, if you have a digital multimeter or you’re willing to borrow or buy one. They’re not expensive and they’ll give you an idea of how your battery is faring. Following the instructions, set the meter to read ‘volts’ and then touch the positive probe to the positive terminal and of course the negative to the negative terminal of your battery. A healthy battery will give a reading of 13 volts or slightly more. That might seem odd for a 12-volt battery, but that’s what you want to see. If you are seeing 12 volts or under, your battery could use some attention. (There’s a difference between the voltage your battery shows at rest and what it delivers under load, say while cranking over your bike’s engine, but that’s a topic for another day.)

What affects battery life and performance?
The factors that impact your battery most are the type of riding you do, how often you ride and how well you care for your battery. 

Your bike’s electrical system charges your battery as you ride. So your battery likes regular rides of over half an hour’s duration. For a lot of us, that might look like commuting. On the other hand if you don’t ride for weeks at a time, or if the riding you do involves short trips and a constant need to restart your bike, that’s hard on your battery. Extremes of heat and cold are tough on batteries, too, as are very rough roads – severe vibration can literally shake the inside of a battery to pieces. So think about how you ride and if you suspect you’re giving your battery a hard time, consider giving it extra care.

Charging in
Most motorcycle batteries are rated at 12 volts and battery chargers for these are easy to find and pretty cheap, although for several good reasons it’s best to buy one that’s designed for bikes rather than cars. When you have your own charger, topping up a battery whenever you need is pretty straightforward.

Before you dive in and buy a standard, no-frills unit you might also consider a maintenance charger, also sometimes referred to as a ‘smart charger’ or ‘trickle charger’. These are designed to stay connected for days or weeks at a time, turning themselves off when your battery is at peak charge, and back on again when the charge drops below a certain level. If your bike sometimes sits unused for long periods of time, a smart charger will both extend the life of your battery and also ensure that it delivers good starting power when you are ready to go. Buy the right charger for your needs, follow the manufacturer’s instructions and you can’t go too far wrong.

More battery bits and pieces
Do I need to top-up my battery with water or acid?
Overwhelmingly, nowadays motorcycle batteries tend to be sealed units labeled ‘maintenance free’. While this term isn’t quite correct – they still need basic care – there is no need, and no way, to top up a sealed battery. If you do discover that you have the type of batter that can be topped up, leave it to an expert – spilled electrolyte will ruin your bike’s finish, not to mention what it can do to your skin and eyes. 

Are all batteries lead-acid?
No. However lead-acid is common because it is cost-effective to produce. More expensive alternatives include Lithium Ion (Li-ion) and Lithium Iron (LiFe-Po). That’s not confusing at all, right? These batteries can be smaller than their lead-acid equivalents, lighter, less prone to leaking…and more expensive.

Can I fit a non-standard battery to my bike?
If you are out to save weight or simply enjoy higher performance, there are alternatives to your bike’s standard battery, but tread carefully. Fitting the wrong battery could cause damage, void your warranty or both. What’s more, batteries such as LifePo types call for different charging methods than lead-acid batteries. If you’re still keen, your Bikebiz workshop tech expert can help guide you on what’s best.

Can I jump-start my bike?
People do it. However, jump-starting a bike is asking for trouble and can result in a fried engine computer, a damaged battery or even an explosion. Acid, chemicals, flames…there’s something there for every thrill seeker, right? If you need to jump start your motorcycle, look at using a battery pack designed for the motorcycle specific job, or call a professional.

How flat is dead flat?
A battery in good condition that’s given a bit of a workout will usually recover to normal performance. But an older battery thrashed until it has no more to give might never come good again, even when re-charged. Chemical changes from extreme use can damage a battery permanently, so use some common sense. For instance, if your bike isn’t firing up, stop and think about why it isn’t starting, instead of cranking it over continually until the battery is dead and the bike smells like roasted roadkill. A bit of mechanical sympathy goes a long way. 

Summing up
Motorcycle batteries have a tough job and are often ignored until they let you down. But while it’s true that batteries don’t last forever, with regular checks and a bit of care, your battery should deliver a long service life, free of surprises and let-downs. 

If you choose to take care of battery maintenance yourself it can be quite straightforward, provided you stick to the recommendations of both the bike manufacturer and the battery maker. Take your time, use your head, and if you have any doubts, remember that regular scheduled servicing always includes battery health checks, so this is your first choice. 

Stay charged, and enjoy the ride!

Click here to read Chapter 9 - Caring for Cables.