Nothing’s quite as disappointing as looking forward to a great ride, only for your bike to not start due to a dead battery. Maybe it’s been a while since you hit the road, or maybe your last replacement was a years ago. Since they self-discharge 1 percent a day, old or infrequently used batteries often go dead eventually.
If your battery is bunk from a winter spent in storage, you may be in luck: It’s possible to reanimate it even from dead-as-a-doornail. The only catch is, you need to do it right, or you could do some real damage. To get you back on the highway as soon as possible, here’s how to charge a motorcycle battery the right way.
1. Take the Battery Off Your Bike
This first step to charging a motorcycle battery may seem like a no-brainer, but disconnecting a battery can be a big pain depending on your bike model. Still, charging away from your motorcycle is important, no matter the inconvenience.
Remember what you’re dealing with: Not only are you running an electric current, but the battery may contain sulfuric acid depending on the type you’ve got. With such powerful elements in play, carelessness or a simple accident can spell disaster. Too much charge at once can melt the casing, sending acid spilling onto your work area, or even make the battery explode. If, God forbid, any of that happened, we know we’d much rather have it occur with our bike out of reach – otherwise, we’d have a whole new set of problems.
Disconnecting your battery requires care and – most importantly – following instructions. If you have your manual, we recommend you give it a gander. If you don’t have it handy, the process follows these steps:
Remove the negative cable (usually black). It’ll be marked with a “-“ symbol.
Keep the negative cable from touching the battery.
Remove the positive cable (usually red). It’ll be marked with a “+” symbol.
Remove the battery from its frame.
The order you disconnect the cables is crucial. Disconnecting the negative first eliminates the chance of accidently completing the circuit while you work, which can result in a bad burn, frying your bike’s fuses, or even a fire.
2. Figure Out What Type of Battery You Have
There are a few different types of chargers for motorcycles, so before you go connecting any cables, you need to figure out what kind of battery you have. There are four popular types, which are the following:
Lithium-based (e.g. lith-iron, lithium phosphate, lith ion)
Absorbed glass mat (AGM)
All of these can be charged with a conventional charger, with the exception of lithium-based types, which have very different internal structures. The sensitive systems lithium-based batteries contain can be damaged by regular chargers. Since the charging process can vary by brand, it’s essential that you always refer to the manufacturer instructions to save yourself some grief.
3. Choose Your Charger
When it’s time to charge, sometimes you have to use what’s on hand. No matter what kind of charger you use, it’ll be some time before your battery is back from the dead. This is because you can wear it out if you try to pump electricity into it too quickly. Ideally, you want to charge at a rate of one-tenth the battery amp rating per hour. For example, a 20-amp battery would take 10 hours to charge at 2 amps.
Remember that bringing your battery back to life is going to result in some degree of damage, since recharging is likely to create a chemical reaction inside. However, diligence – with the help of certain battery chargers for motorcycles – can minimize the destruction and keep your reanimated battery running longer.
These bad boys are probably the most convenient charging tool, as they do all the work for you. They can minimize damage by changing the charge rate at different intervals, and some even have an electrical pulse to speed along the necessary chemical reactions. When charging is done, smart chargers shut off to prevent overloading.
Float chargers aren’t quite as fancy as the smart kind, but they do shut off when finished. If you leave one attached for a long period of time, it’ll turn back on to match the self-discharge and keep your battery topped off.
If you’re using a motorcycle trickle charger, you’ll need to keep an eye on it. These “manual” types don’t have an automatic shut-off, which means you have to regularly monitor your battery’s health.
So all you’ve got is a car charger. Can you use it to charge your motorcycle’s battery?
The short answer is – don’t. Car chargers have way too high a charge rate and can blow your battery.
The long answer is – yes, but get ready for some math. You can mitigate the high amperage by running appliances in parallel – light bulbs are a good option since their amperage is clearly marked and you can easily tell if they’re receiving electricity. Make sure the charger amps minus the appliance amps are equal to or less than the one-tenth rule.
Keep an eye on your set-up to make sure nothing disconnects or overcharges. If you opt for charging a motorcycle battery with a car charger, we wish you luck.
4. Charge up Your Battery
Before you hook anything up, make sure you’re in a well-ventilated area, as batteries can produce hydrogen gas during charging. Make sure you hook up the cables in proper order and to the correct terminal, or you could end up with a fried charger.
If all goes well, you’ll end up with a living battery ready for the road. If not – sorry, buddy, but it’s time to visit the auto parts shop and get yourself a new one. Trying to push start or otherwise run your motorcycle can damage your bike’s electrical equipment.
When your battery goes dead, you have options: Before you pay up for new parts, try using a trickle charger for motorcycles or other charging tools. Resurrecting a battery can mean money saved and keep you from wasting decent parts.