Lithium motorcycle batteries are becoming increasingly popular thanks to their small size, lighter weight and non-toxic construction.
Rechargeable lithium batteries in the past have been used for small electronic devices such as mobile phones, laptops and digital cameras.
The incredible advantages of these batteries outweigh those of a standard lead-acid type which are commonly used for motor vehicles. One of the biggest advantages is that a lithium battery takes a long time to go flat. So if like me, one of your main expenses is fitting new batteries to bikes that spend most of the year tucked away, a lightweight lithium battery is for you.
Motorcycle manufacturers are beginning to launch bikes fitted with lithium batteries, especially racing style bikes which benefit from the reduced weight.
If you’re considering swapping out your lead-acid battery for this modern upgrade, this article explains a little more on what you need to know including the pros and cons and a handy jargon buster.
Table of Contents
- Lithium batteries have a power density 3 to 4 times greater than lead acid, so less material is required which is where the weight saving comes in. A lithium battery is about a quarter of the weight of a lead-acid battery
- Lithium batteries eliminate the risk of leaking battery acid
- They have a higher cranking power relative to their size and weight so can start your bike quicker
- Lithiums have a low self-discharge rate compared to lead-acid batteries
- Lithium batteries take less time to charge than standard batteries (roughly 1 - 2 hours compared to 12 hours for a standard)
- Economically better based on their lifespan which is twice as long as a regular battery
- Your regular battery charger won't charge a lithium battery properly
- If your battery is cold it will not perform as well
- They can cost up to 30% more than their lead-acid counterparts
- If a Lithium battery runs down too much, you cannot recover them (which could be a problem for those in a colder climate or bikes laid up for a very long time)
- There's a chance of overheating if too much voltage is used during charging, so you need a dedicated lithium charger
- Using a charger which isn’t designed for Lithium batteries can damage them, resulting in less battery life or irreparable damage
What your motorcycle battery has to do
Let’s be honest. We don’t love our motorcycle batteries like we love our engines. A battery is all fine and dandy when it works but the son of a devil when it doesn’t. But let’s show it some appreciation, a motorcycle battery isn’t just there to get the engine started. On a typical motorcycle, it has five different roles to play.
– Starting – Supplying power to crank the engine over.
– Lighting – Delivering power to the lighting system without the engine running.
– Ignition – Supplying the ignition system with power while the engine is cranking.
– Charging – Absorbing any spikes in power and stabilising the bike’s voltage .
– Support – Supporting areas like the bike’s ECU or immobiliser when the engine isn’t running.
Common Lithium Battery Questions
Size / Weight comparison
The biggest difference between standard lead-acid batteries and lithium varieties is the size and weight. If you replace your standard motorcycle battery with a lithium alternative, you could save over two-thirds of the weight while keeping the same level of power output. Lithiums can be a lot smaller than lead-acid but the smart manufacturers make the lithium casings the same size to make t easier to swap for your old battery.
Fitting with Foam
Some lithium batteries are physically smaller. By using foam padding provided, you can attach as many blocks as you need to pad out the battery. The foam gives a little room for manoeuvre and prevents vibrations. Shido and JMT batteries are different in that they are the same size as an OEM battery. Ideal if you don’t want to mess around with foam padding.
Lithium batteries require special lithium battery chargers as they charge differently than standard batteries. Choose a charger that has an automatic cut-off, this way, your battery won’t overheat if you forget to unplug it.
Cut Off Switch
Built-in cut off switches automatically switch off the battery at a certain voltage. This helps preserve the battery’s lifespan, prevent overheating or other accidental damage. You can also fit a manual switch into your wiring loom to disconnect your battery, to prevent drain when you’re not using the bike.
Quality Lithium Battery Brands
There are countless motorcycle battery brands. It’s hard to pick the best motorcycle battery as it depends on your budget and what you want from your battery. One bit of advice is: avoid the cheap batteries on eBay – they are a false economy.
Listed below are other well-known brands:
JMT German-made batteries come with a 2-year guarantee. They also have a built-in LED charge level indicator which is so simple, you wonder why no-one’s done it before. They are the same size as your OEM battery but far lighter, meaning they are a straight swap – just plug and play.
Japanese manufacturer Shido are one of the leading suppliers of Lithium-based motorcycle batteries. One of the factors that make them a good bet for most bikers is the fact that the physical size of the battery is the same as a conventional battery, meaning it’s a straight swap with no need for foam padding.
You’ll find this brand on Amazon, they make a wide range of lithium motorcycle batteries and they get good user ratings.
Other good brands
Dutch firm makes lithium batteries for multiple applications with a large range of motorbike fitments.
High performance lithium ion motorcycle batteries designed with the smallest physical size in mind. Made in Italy, they are the OEM choice for some motorcycle manufacturers and a good choice if you are building a custom and space-saving is important
Quality lightweight motorcycle battery that’s no pricier than a decent lead-acid equivalent. You can get a lighter lithium battery but the Shido is already a lot lighter than your OEM lead-acid battery. It’s the same physical size as an OEM battery, making them a straight swap, no messing around with foam padding. If you are after the ultimate in light weight, check out Aliant.
German-made batteries that come with a 2-year warranty (that’s about as long as a regular lead-acid will last). JMT lithium batteries are one of the lightest on the market. They also have the same physical size as your OEM battery making fitment a doddle. The built-in LED battery status checker is a nice touch. The battery should last at least 5 years.
Lithium vs Lead Acid Weight Comparison
We’ve taken 3 common motorcycle battery sizes and compared a typical lead-acid battery weight to that of a lithium battery
|Battery||Lead Acid Battery Weight||Lithium Battery Weight|
|YTZ10S / LTZ10S||3.2kg||0.9kg|
|YT12B-BS / LT12B-BS||4.1kg||1.1kg|
|YTX20CH-BS / LTX20CH-BS||6.1kg||1.5kg|
A spotlight on JMT batteries
What makes a decent lithium battery? Here’s an insight into JMT.
Higher starting power
JMT Lithium Batteries are able to provide a higher starting current (CCA), which ensures a smoother start. Since lithium batteries have less internal resistance than lead-acid batteries, they can achieve this higher starting current using much less Ah.
Longer life span
The lifespan of a battery is measured by the number of times it can undergo a charge and discharge cycle. A regular lead-acid battery can be charged and discharged for about 350 cycles. The JMT Lithium Battery, however, allows for approximately 1200 load cycles, giving it much longer service life.
Taking its entire life span into account, a SHIDO Lithium Battery works out to be about half the price of a regular lead-acid battery, making it much more economical.
When not in use, lead-acid batteries discharge quickly. A bike won’t be able to start after just a few months of not being used. With a JMT Lithium Battery, however, self-discharge is very low. Here, even after two years of not using a bike, it will start effortlessly. Bear in mind though, power consumers like alarm systems do negatively affect the discharge rate.
Lead-acid batteries lose their ability to retain capacity over time. There is a marked difference between the starting power of a brand new lead-acid battery and one that is a few years old. This problem does not occur with JMT Lithium Batteries as the starting current remains high for most of the battery’s life.
The maintenance-free JMT Lithium Batteries contain no environmentally hazardous substances. As they can neither leak nor explode, they can be fitted in any position, including upside down. JMTLithium Batteries are IP68 waterproof.
Depending on the model, JMT Lithium Batteries are three to four times lighter than the equivalent lead-acid batteries. For a common fitment like the YTX9-BS you’ll save around 2.2kg
Size-wise, JMT Lithium Batteries match the dimensions of their equivalent lead-acid batteries. Universal terminals allow for easy connection.
What is a smart battery?
A smart battery keeps you informed about the health and life of your specific battery.
By using an app and connecting your battery to your smartphone via Bluetooth, you have access to all the information you may need. Via the app, the SHIDO CONNECT smart battery allows you to check the state of charge (SOC), as well as the expected end of life of your battery.
Total voltage and the voltage of each individual lithium cell in the battery can also be checked. The app also lets you check the temperature of the battery and will notify you if it is too hot.
You will also be notified if your battery is overcharged or if the voltage is low. If you won’t be using your bike for a while due to long term storage or through winter, activate Bluetooth sleep mode via the app or the battery.
Sleep mode is also automatically enabled if the bike hasn’t been used for 15 days.
To re-activate Bluetooth for the SHIDO CONNECT smart battery, either start the engine, activate Bluetooth directly on the battery, or charge the battery externally.
It’s a handy way to quickly check your bike’s battery and if you’re guilty of letting your batteries go flat, this will help.
Motorcycle Battery Jargon Buster
You may see lithium batteries described as LiFePO4 batteries. This is the chemical name for Lithium (Li) Iron (Fe) Phosphate (PO4) which is essentially the chemical makeup of the cell.
This is a standard rechargeable battery most commonly found in motor vehicles. Vehicles need a high current to power engines which is why these large power-to-weight ratio batteries were originally used.
A measurement of electricity (battery output example, 12V, 24V etc.)
Ampere hour (Ah)
An ampere hour, or amp hour, is the amount of energy charge in a battery that will allow 1 ampere of current to flow over an hour. The higher the Ah, the longer a battery will go before it needs charging.
Stands for Battery Management System and helps prevent a lithium battery from overheating (and melting!).
Lithium Motorcycle Battery FAQs
Can I charge a lithium battery with a regular lead-acid battery charger?
No. While it is possible to charge a lithium battery with a lead-acid charger in some circumstances, you have to know what you are doing. A lead-acid charger works in almost the opposite way to a lithium battery charger and if you don’t know what you are doing, you’ll overload your lithium battery, causing cell failure (ie rendering it useless ) and possibly causing a fire.
Far better to buy a proper lithium battery charger.
Do I need to change my motorbike’s charging system?
Your motorcycle should seliver a charge at 13.8v to 14.4v and if it does, then you won’t need to modify it when you switch to a lithium battery. When you test your battery with a voltmeter, if the voltage rises above 14.4v at any engine speed it isn’t recommended to fit a lithium battery as your bike will overcharge it, which could shorten its life.
How long should a lithium motorcycle battery last?
Correctly maintained, a lithium motorcycle battery should give you at least 48 months of use. However if you don’t ever charge it and rarely use the bike, it could be dead within 12 months. If you rarely use the bike and don’t have access to power where the bike is parked – it’s worth removing the battery and giving it a full charge every couple of months. Or even better – get out and ride!
Do I need to charge a new motorcycle battery?
To give your bike’s battery the best start in life, stick it on a motorcycle-specific battery charger when it’s new and top it up until it’s fully-charged. Your bike won’t be able to fully-charge a battery in the way a charger can.
If I disconnect a motorcycle battery will it still go flat?
If it is a lead-acid battery, then yes. As soon as a battery has been commissioned (i.e the acid is in place) it will be discharging. It will, however, discharge less quickly than if connected to a bike, as even with the ignition off, there may be a tiny draw of current from the battery (powering things like the immobiliser).
Why won’t my motorcycle start?
A motorcycle battery is a ‘live’ product, that is to say, once it has been commissioned, it is giving off energy, discharging. So if you don’t keep your battery charged it will eventually get to a stage where it doesn’t have the power to crank the bike.
A lithium-based battery will also go flat if disconnected but it will take a lot longer to lose its power and won’t sulphate, meaning you can charge it up again years later.
My motorbike battery keeps going flat
This can be down to several reasons:
Firstly, your regulator/rectifier could be dead. If you get the bike running, rev the engine. If the lights brighten, your reg/rec is probably OK. If they dim, the reg/rec might be on its way out or dead.
Secondly, your battery terminals might not be on properly. It used to be that you could fit your battery, your lunch and a couple of copies of Razzle under your seat but these days, space is as a premium and batteries are even more fiddly to remove and replace. When I drop a battery bolt or one of those fiddly square nuts, I use this magnetic pick-up tool to save the day. Honestly, it’s a lifesaver. As fiddly as it is to fix your battery screws in place, don’t cut corners; if a terminal pops off, it could leave you stranded.
Less common these days but an aftermarket alarm or immobiliser is a prime suspect in the mystery of the flat battery. If you have one fitted, make sure the wires aren’t loose or shorting out anywhere.