There’s little more frustrating than hopping on your bike, geared up, and ready to head out for a ride only to realize that you left the key on and drained your battery. We’ve all been there, and it’s frustrating.
While a simple solution to get out on the road is to jump-start your bike (more on this later), You should charge your motorcycle battery back to a healthy state with a dedicated charger. While you can accomplish this with a nice long ride, your best bet is to throw it on a charger and hope it’s not from being discharged too much.
In this article, we’ll discuss the motorcycle battery charging system, what types of chargers are best, and how long you should charge it to keep it functioning.
Types of Motorcycle Batteries
Before we jump into charging your battery, it’s important to first look at the different types of batteries found in your motorcycle. The most common battery type will be a lead acid battery. There are several different styles of lead acid batteries, but all utilize the same chemical reaction process. The least expensive, and one that has been around the longest, is a conventional wet cell lead acid battery. These 12-V batteries require regular maintenance in the form of adding distilled water. The liquid (water and sulfuric acid) in these batteries is lost as it vents hydrogen gas. Therefore, it will lose water over time, and you’ll need to replenish it.
However, if you have a modern motorcycle, it will probably have an Absorbent Glass Mat (AGM) battery. This battery is a similar technology, but it’s sealed and maintenance-free, meaning you won’t need to add water.
You may also have a Gel battery in your bike, which is just another type of lead acid battery. It uses gel silica to turn the acid inside the battery into a thick liquid. These batteries are pretty robust and ideal for tight spaces. However, they’re not very common in modern motorcycles (although there are some good ones out there).
You may also have a lithium battery in your bike. Still, since this battery style is an expensive and newer technology, you likely only have this type of battery if you put it in yourself or the previous owner installed one. However, before charging, you must first determine what type of battery you have. Different batteries may require different charging systems and even a specialized charger.
Do I need a special charger for my motorcycle’s battery?
Back in the days of traditional 12V wet lead-acid batteries, charging was a pretty straightforward process. You haul out the old charger, dust it off, connect the jump cable alligator clips and turn it on. However, with the advent of newer battery technologies, an older charger may not be smart enough to charge and protect your more modern battery.
The good news is that many of the newer chargers are a little smarter than your dad’s old meter gauge one. For example, many chargers will have a built-in sensor that detects the battery’s chemistry and can be adjusted to provide the correct charging amperage.
For the most part, a smart charger will usually work just fine on traditional lead acid, AGM, and Gel batteries. However, before connecting it, read the manual and make sure it’s capable of charging your style of battery.
Many new chargers will be fully automatic and do more than simply add more juice to the battery. For under $100, you can find a do-it-all charger that will automatically diagnose, recover, charge, test, and maintain your battery.
However, if you have a lithium-ion battery, you will likely need to use special chargers capable of handling this kind of battery. A lithium battery is a completely different type of battery than a lead acid one. For this reason, it’s critical only to charge it with an approved charger. Some battery manufacturers only recommend using certain models of chargers, so it’s a good idea to read up on your lithium battery’s specifications to ensure that you don’t damage it or, worse, catch your bike or garage on fire.
How long should you charge your battery?
Since you may have come here for this answer, I’ll do my best to answer it. However, there is no simple answer that applies to every situation. Luckily, depending on your charger, you may not have to make that decision.
A modern smart battery charger will do most of the work for you. If you don’t have one yet, I recommend shopping for one with a fully automatic charging process. Essentially, the charger will read the battery, diagnose its condition, and slowly charge it at an ideal rate until it has a full charge. A smart charger won’t overcharge a battery if it has an automatic shutoff, and it’s safe to leave it on until it is fully charged. When buying a charger, look for one with “end-of-charge control.” This option is probably the most important feature of a smart charger.
If you have a flat battery, it will usually recharge within 5-6 hours. However, if it’s deeply drained, it may take 10 hours and up to 24 to charge it fully. If you’re charging overnight, only use a regulated automatic charger. You want to ensure that it automatically controls the output, adjusts if necessary, and turns off when fully charged. Most modern reputable chargers will do this.
Lithium batteries will also have a similar smart charger designed specifically for them. However, lithium batteries charge much faster than a 12V lead acid battery. An equivalent lithium battery can fully charge in 2-3 hours (as compared to 5-10 hours of a LAB).
How do you connect a charger to your 12V motorcycle battery?
Your charge will have two clamp-on chargers, similar to jumper cables. First, connect the black (negative) cable to the battery’s negative terminal. Next, connect the red cable to the positive terminal. Your bike may also have a quick connect terminal installed on the battery, allowing you to plug in a compatible charger easily.
Can I charge a drained battery by riding my motorcycle?
If you simply forgot to turn your key off for an hour and your bike won’t start, even though the rest of the electronics come on, you probably have a moderately drained battery. In this case, you can jump-start your bike and take it for a long ride to recharge it.
Every motorcycle will have some way to charge your battery while riding. This is a safety feature built into every bike. When the engine runs, the motorcycle alternator will add juice to the battery (just like your car does for your car battery). So it will work while riding or when you keep the bike idling.
A portable jump starter is a good tool to keep in your bike kit. In recent years, these devices have come down in price and size and are now easily packable in your tool kit. They look similar to portable battery packs for charging phones or laptops but allow a burst of energy needed to start an engine. They also come with jumper cables, which makes hooking it up to the battery simple. They’re a must-have for a road trip. Here’s a great option for motorcycle riders:
However, if the lights were on overnight and you jump-start your bike, the battery management system in your bike will give it a charge, but it may not be enough to charge your battery fully. The best way to charge a drained battery is with an external charger that plugs into an AC power outlet. So even if it appears that your bike was able to give it enough juice to restart, your battery may not be fully charged, which isn’t good for the life of the battery.
Completely draining your battery can damage your battery, and a bike alone may not be able to repair it. However, a smart charger will sense the drain in your battery and charge it appropriately, attempting to recover as much functionality as possible. If in doubt, it’s always best to charge your battery with a charger when drained.
How can I tell if my battery is beyond repair?
If your battery suffered a deep drain, or you repeatedly left the lights on, and it’s not taking a charge, it may be time for a new battery. The only way to know for sure is to use a battery tester. Your charger may have a built-in tester, but many don’t. You don’t necessarily need to go out and purchase one. Instead, if you take it to a local auto parts store, many of them will test your battery for free It will test the battery capacity.
How to choose the right battery size for your motorcycle?
At some point, while owning your motorcycle, you will need to replace the battery. This need could be due to damage to the battery from completely draining it, or it could simply be because the battery has reached the end of its life.
The first step in choosing the right battery is the find the correct size. Assuming you had the correct battery in the bike, to begin with, you can look at the old battery to determine a few key pieces of information. First, you’ll need to identify your bike’s required cold cranking amps (CCA). The CCA is the number of amps that can be delivered for 30 seconds to maintain at least 1.2 volts per cell: how much energy is needed to turn over your engine. Each bike will have its own CCA requirement, and you must ensure the battery matches that.
The other thing you need to determine is the physical space required for the battery. You’ll need to measure the battery compartment’s width, length, and depth to find one that will fit your bike. If you have an old battery, it’s easiest just to measure it or write down the size of the battery (if it has one). You can always buy a smaller battery, but not a larger one that won’t fit into the opening.
Motorcycle battery chargers:
When you purchase a new motorcycle, it’s a good time to look at the battery and ensure you have a charger capable of charging it. If not, it’s time to go shopping because, at some point in owning it, you will need to give it a charge.
When shopping for a charger, remember the adage, “you get what you pay for.” While the internet is overflowing with cheap electronics, you shouldn’t simply look for the cheapest option. An incompatible charger, or a low-quality one, could potentially damage your battery. However, you can still get a decent charger at an affordable price.
The first thing to consider when purchasing a charger is the type of battery you have in your bike. Most modern chargers can handle a variety of lead acid motorcycle 12-volt batteries (traditional wet cell batteries, AGM batteries, gel cell batteries). However, double-check this before buying one. In addition, a Lithium battery will need a special charger. While some on the market do both, check the documentation for your battery to ensure you have the right charger type.
Next, you’ll want to look at the battery’s Amp Hours (Ah) rating. The battery’s Ah rating describes how long the battery will last at a fixed discharge rate. This number is usually calculated using a 10-hour period as a benchmark, So if you have a 20 Ah battery, it can discharge 2.0 amps continuously for 10 hours. When choosing a charger, make sure it can charge up to your Ah rating. For motorcycle batteries, it isn’t hard to find an affordable charger that can meet the Ah rating (motorcycle batteries are smaller than larger car batteries). If the Ah is larger than the charger, it will likely still charge the battery but will do so at a lower rate.
The following advice to remember is that batteries like to be charged slowly. A trickle charger is going to be your best bet. This type of charger will slowly charge your battery over a longer period (at low amperage), allowing you to keep the battery in good condition. A fast charger can damage some lead acid batteries, so keep this in mind when shopping.
The other type of battery charger is a float charger. This charger is designed to shut down once the battery is full to avoid overcharging. When storing a battery with a float charger, if the voltage drops, it will kick back on to maintain it (often called a battery tender). Many trickle chargers will have a float option built in, so this may be an option you want to have when shopping. However, be aware that lithium batteries don’t like float chargers, so this is likely only useful for lead acid batteries.
Battery Charger Recommendation
If this all seems confusing, you may appreciate the suggestions below. The following charger, the Noco Genius2, is one of my favorites and has all the features you need to safely charge any battery (even many lithium-ion batteries- but check your battery documentation first). It can charge, maintain, and repair almost any battery.
Noco Genius 2
This little charger, which you can find for under $50, does it all. It’s super easy to use and has one single control (mode) for selecting the type of battery you’re charging. Once you do that, it’s as easy as connecting the charger and leaving it on until the battery is fully charged.
The GENIUS2 is a 6-volt and 12-volt battery charger, battery maintainer, and battery desulfator rated at 2-amps for lead-acid automotive, marine, and deep-cycle batteries including flooded, gel, and AGM. It also has a lithium-ion battery mode, but I haven’t used it for this yet.
This nifty little charge is also compact and easy to carry in your luggage. A small charger is one of my must-have features for my motorcycle as I like to pack it when I travel (just in case). It’s also really smart and provides peace of mind when charging. The Genius 2 has an integrated thermal sensor that detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates. The charger will also detect sulfation and acid stratification and restore lost performance for stronger engine starts and extended battery life.
The charger will also bring a dead motorcycle battery back to life. It can detect a dead battery as low as 1 volt. If you have a completely depleted battery, you can select force mode and begin charging dead batteries down to zero volts. It will also detect damaged batteries and repair them. When fully charged, it will actively monitor the battery and maintain it- it’s safe for continuous operation without user intervention and has zero risk of overcharging your battery.
This charger is also great around the house and can be used on other batteries for your cars, RVs, boats, or lawnmowers. While this will charge larger batteries (such as big RV Ah batteries), it will take a long time. While there certainly are larger chargers on the market (Noco makes this same model with more charging volts), you don’t want a big charger for a motorcycle battery. This one is a good mix of power and versatility and is safe for your bike.
If you have a motorcycle, you will inevitably run into a situation where you have a dead battery and need to charge it. If you have the right charger, pay attention to the battery type, and give it some time, it’s really easy to bring your battery back to life. Motorcycle batteries like to be charged slowly. If you ensure your battery has a healthy charge and take care of it, it will last you many years.
There will be times when you need to jump your bike to get back on the road, but don’t rely on this as your only form of charging your battery. When in doubt, throw it on a charger. If you have an automatic charger described above, it’s a set it and forget it type of process. A happy battery makes for a happy rider.