Whether you are a motorcycle enthusiast or not, the battery that powers your electric motorcycle is an important consideration. The type of batteries available to choose from can be confusing and daunting for some people. That’s why we want to give you some information on how to choose the right electric motorcycle battery!
Advantages of Lithium batteries
Extremely lightweight! For example, a typical 16Ah battery weighs 5kg. A replacement Tritek Lithium battery weighs an amazing 1.3kg complete with the built-in Battery Management System.
Very high cranking power relative to size and weight.
Very low self-discharge rate (about 3% every month).
Very small size.
No internal liquids or acids that can spill – can be mounted in any orientation.
Unlike lead-acid batteries, Tritek lithium-ion batteries do not produce explosive gasses like hydrogen when charging or discharging.
Very fast charging times typically a discharged battery can be fully recharged in 1-2 hours. By comparison, a discharged lead-acid battery will take over 12 hours to charge to full capacity.
Vastly superior reliability and very long service life compared to lead-acid batteries. The target life for a lithium motorcycle battery (with a built-in BMS) is ten years!
Lower per year cost of ownership than legacy lead-acid batteries.
Lightweight and high cranking power?
The 22Ah Orange battery above is from a Chilwee and weighs over 5kgs and is rated at 200 Cold Cranking Amps. The Tritek Lithium-ion Battery replacement for the same bike is rated at 270 Cold Cranking Amps and 360 PCA! Incredibly weighs just 1.4 kgs.
For race use, we would recommend a smaller battery for this bike weighing just 860 grams.
Lithium-ion (especially those with built-in Battery Management Systems) have extremely fast charging times. Typically within 5 minutes of starting your motorcycle, your battery will have fully recovered the capacity that was used in starting your bike.
A battery that has been discharged to the point where it can no longer turn over your starter motor can typically be fully charged with the external charger in just 1-2 hours. By comparison, a discharged lead-acid battery will take over 12 hours to charge to full capacity.
Superior reliability and long service life of lithium batteries compared to lead-acid batteries
Customers should expect a lithium battery with an in-built BMS to last 5 to 10 years. By comparison, recent user polls showed that over 21% of lead-acid batteries fail in the first two years, and 37% fail within just 3 years!
By comparison, warranty records show the failure rate for Tritek motorcycle batteries was less than 2% in the first two years. (Tritek’s confidence is demonstrated by one of the industries only, full value 2-year replacement warranties).
Due to the high self-discharge rates of lead-acid batteries and the periodic use of motorcycles most experienced motorcycle owners usually purchase a lead-acid battery smart charger to maintain and condition their lead-acid batteries.
Good quality smart chargers such as the CTEK units typically cost as much as the purchase price of a lead acid battery.
Lithium batteries have a very low self-discharge rate. A lithium battery will typically be able to sit on a shelf uncharged for six months and still be able to start your motorcycle. For this reason, most customers do not bother buying a smart battery charger/tender for their lithium batteries.
Cost comparison of legacy lead-acid batteries Vs Tritek Lithium-ion batteries
Motorcyclists as a breed are fast to catch on to new technology and cost savings. It used to be that racers bought Lithium batteries to save weight. But commuters and weekend riders are now buying Lithium batteries to save money. In fact, we sell many times more Lithium batteries to commuters than we do to racers.
Most people own each bike for a few years and most motorcyclists have worked out that the per year cost of short-life lead acid is fairly expensive when compared to the yearly cost of owning a Tritek Lithium battery that will last between 5 and 10 years.
Especially if they also cost the expense of purchasing a smart charger, which costs as much as the purchase price of a lead-acid battery.
Many owners will discover a Tritek battery will work out to be the cheapest option to own and we have had several customers who when they traded up bikes swapped their Lithium battery into their new bike. This is only possible if the new bike and the old bike use the same size battery.
Are there issues with Lithium-ion batteries I should know about?
Yes! Tritek’s product manager, Ivy Peng has a background in electronics (Chinese Certificate of Engineering, telecommunications/radio/electronics). We spent some time researching Lithium-ion batteries for motorcycles and looked at many suppliers.
Initially, this was a frustrating exercise because while there are many advantages to Lithium batteries there are several potentially costly issues that can all be mitigated by good design. We discovered many brands on the market were just interconnecting raw lithium cells in a plastic case to create a crude and unreliable battery.
With this simplistic approach, there are several potential issues that are not being mitigated, such as:
- Potential short lifetime, due to physical cell separation.
- Bricking (becoming so flat that it cannot be recharged).
- Rapid temperature build-up if short-circuited.
- Short cell life due to the individual cells within the battery not being evenly charged every time the battery is charged.
- Excessive and rapid temperature build-up if charged at excessive voltages.
- Decreased performance in colder temperature.
- Rapid and destructive overheating in the case of a short circuit.
As you will see by incorporating an inexpensive BMS (Battery Management System) and intelligent design all of these factors can be mitigated.
Are all Lithium-ion batteries made equal?
There are still some lithium battery vendors offering batteries without a built-in BMS (Battery Management System) or any internal safety protection devices.
Batteries that do not include inbuilt Battery Management Systems and protection circuitry have unfortunately tarnished Lithium batteries’ reputation for reliability and confused customer expectations on what life span they should expect from a lithium battery.
Hopefully, batteries without inbuilt BMS systems will shortly become a thing of the past.
Are there physical durability differences between different brands of Lithium-ion batteries?
One of the key problems with using lithium batteries in Jet Skis and motorbikes is how you interconnect the cells. The traditional method is to screw or solder the connections onto the cells. Both methods are potentially problematic when subjected to vibrations and impacts.
Screws work loose and soldering is just too weak. Welding would be great but in the past, the heat generated in the process would damage the cells. Failure stories and caution over this issue were one of the key factors why we didn’t jump into the Motorcycle Lithium battery market.
Tritek addressed this issue by using laser welding technology which is extremely fast and pinpointed so that they get the benefit of welding without excessive heat soak. I am told that the technology required to do this is expensive.
What is Bricking? Should I be concerned about it?
The first generation of cells used in Lithium Motorcycle batteries that came on the market in 2010 used the best cell technology available at the time. These earlier cells were prone to bricking. Bricking is a term to describe what happens when you flatten a lithium cell to the point it can not be charged again.
Hence the better brands incorporated Microprocessor controlled BMS systems, that would disconnect the cells from the external battery terminals before the battery could discharge too far. The latest generation of cylindrical Lithium-ion cells is much more robust in this respect.
It is still a good idea to never allow your battery to completely flatten to maximize its lifespan of the battery. While recharging a completely flat battery may give you the impression that it is working perfectly again.
We would advise that completely flattening your battery is likely to reduce its life span, and consequently many manufacturers will void your warranty should you do this.
Is there any short-circuit protection?
Lithium batteries have a very low internal resistance and this is one of the reasons such a tiny battery can provide such a power kick to your starter motor.
Unfortunately, this same property makes it very risky to short-circuit a lithium battery. Without a fuse correctly rated fuse in the circuit for the size of the battery you are using, a lithium battery can very quickly destroy itself and potentially generate enough heat to damage your motorcycle.
Modern lithium batteries such as the Tritek have fuses inside the battery between the positive terminal and the lithium cells. This fuse will be of the correct type and correctly rated for the size of the battery. All Tritek batteries sold have internal fuses.
Never assume your battery has internal short-circuit protection. If it doesn’t say so on the battery or in the manual then it doesn’t have it! If you are not sure, ask the supplier!
When you install a lithium battery without an internal fuse in your motorcycle you should examine the rating of your bike’s main power fuse (normally situated on the positive power lead right next to your battery) or fusible link (a thinner section of power cable that is designed to melt and break the circuit with excessive current or temp) and check that it the correct type and rating for the battery.
Your lithium battery supplier should be able to advise on this.
If you are only using an external fuse it is very important that when wiring in accessories, heated grips, GPS units, radar detectors, etc the external fuse is not bypassed. Of course, it’s not possible to bypass an internal fuse.
Short cell life due to the individual cells within the battery being either under or overcharged
If Lithium-ion batteries are charged without a BMS the internal cells do not charge evenly. This can lead to greatly reduced battery lifespan in many cases to as little as 2 or 3 years.
Most Chinese Manufacturers that still do not make batteries with a built-in BMS recommend that you also purchase an external mains-powered BMS charger when you purchase their Lithium batteries. So that you can perform periodic cell balancing.
Of course, this does not provide the required protection, cell balancing, and other BMS functions while you are riding the electric motorcycle. Lithium batteries now have a BMS built into the battery to protect it and ensure it is being properly charged while you are riding the bike.
In the picture below of the battery with the top cut off, you can clearly see the BMS (Battery Management System) circuit board.
Why do Lithium-ion batteries need cell balancing during the charging process?
Likewise, cells in all types of batteries (lead acid, nickel metal hydroxide, and lithium) that are consistently overcharged also will last years less than cells that are consistently maintained near the correct full charge.
If you start with a 10-year target life and then just lose a couple of years of the lifespan because you undercharge one or more cells in the battery pack, there is no way to get these years back by whatever else you do to condition the battery.
Charging cells too quickly will also greatly reduce the lifetime of any type of battery.
With all types of batteries the faster each cell charges the hotter it gets. As each cell in a lead-acid battery charges, the internal resistance of the cell increases. If one cell begins to charge faster than the others, its higher resistance slows down its charge rate in comparison to the other cells.
Hence cells in lead acid batteries automatically limit their charge rate and balance with each other as they charge.
Unfortunately (from a charging perspective) with the cells in a Lithium battery the exact opposite occurs. As each cell is in a Lithium-ion charge, the internal resistance of the cell decreases. If one cell begins to charge faster than the others, its resistance decrease.
The lower resistance further speeds up its charge rate in comparison to the other cells which further decreases its resistance and further increases its charging rate.
Hence lithium cobalt battery cells in Lithium batteries do not automatically balance with each other as they charge. One cell can be fully charged and the one next no. This is a problem because cells in all types of batteries last longer when they are maintained near full charge.
If the charging of each cell is not individually monitored and controlled with a BMS charger the process can lead to premature failure at best and at worst in very rare circumstances to catastrophic and dramatic temperature-induced failure. With an inbuilt BMS this is monitored every moment the battery is being charged while you are riding the bike.
Tritek was the first china motorcycle battery manufacturer to eliminate the extra expense of having to purchase an external mains-powered BMS charger and eliminated the hassle of having to regularly rebalance the charge of individual cells. They did this by incorporating a multi-function microprocessor-controlled BMS system inside the battery.
With an inbuilt BMS, you can charge your lithium battery packs directly from the bike’s alternator without shortening their life and you will never need to balance the cells with an external BMS system.
The aim is to put a Lithium battery into an electric motorcycle as a plug-and-forget replacement battery that will do its job for tens of thousands of kilometers over a 10-year target period and never need any special treatment with external BMS chargers or whatever.
We already have batteries that have done over 35,000 km in road bikes and they show no sign of losing any of their performance.
This extended lifespan is why there is a microprocessor-controlled BMS in the Battery. If a lithium battery doesn’t last at least twice as long as a lead-acid battery how could you accrue cost savings?
Why can’t Lithium batteries be charged by a standard automotive workshop trickle charger? Well, actually they can be as long as they with a charger that meets your lithium battery supplier’s guidelines.
The guidelines for the older Tritek batteries are different from the guidelines for the new batteries. You should check the guidelines with your battery supplier to ensure that you do not damage your lithium battery or void your warranty.
The best way to maintain the charge in a lithium battery is to ride your bike and let your bike charging circuit and the BMS in the battery do their thing.
Before installing your new Tritek battery please ensure (using a voltmeter across your battery terminals with your bike running at about 3000 rpm) that your motorcycle’s regulating system is functioning correctly and its voltage output is regulated to no more than 15 volts.
Do not use a smart charger that has a Desulphation stage!
Many automotive lead-acid batteries do not have satisfactory voltage regulation. Many of them just rely on the current limitation due to the increasing internal resistance of a lead-acid battery as it gets closed to fully charged.
This lack of satisfactory voltage regulation means that with some automotive trickle chargers you could see the voltage climb to well over 15 Volts as the Lithium Battery gets close to full charge. While a lithium battery might survive charging rates over 15 volts for short periods you could probably be unknowingly shortening its lifespan.
We believe it is preferential to maximize the lifespan of your lithium battery, that you use a lithium mains charger supplied by your battery manufacturer.
It is common practice to leave a lead-acid battery connected to a smart charger when not in use to extend the life of the battery.
This is not necessary or good practice with a lithium battery. Lithium batteries will hold their charge when not in use many times longer than lead acid batteries. For this reason, most of our customers never purchase a mains-powered lithium charger.
If you wish to charge your battery during long intervals between using your bike, you can periodically charge it with a main charger. Once your main charger detects the common electric bike batteries are fully charged it will stop the charging process.
However, It is not best practice to leave any 230V appliance whether it be a TV or a battery charger turned on unnecessarily. Once your battery is charged we recommend you turn it off and disconnect it from the battery.
Winter Storage and charging with a battery charger: To store your battery off-season measure the voltage to make sure it is fully charged, 13.2 volts or greater – recharge if necessary. Disconnect the negative battery cable to prevent any parasitic current drain by your motorcycle – or store the battery separately from the electric bike’s motor system. It is a good idea to do electric bike volts measurements while in storage. If you wish to charge your battery while in storage we recommend taking your bike for a short run or periodically using a Tritek charger. These can be purchased from your Tritek supplier.
Please note Tritek batteries are equipped with an internal fuse for your safety. If you have a high current short this fuse will blow to prevent the battery from overheating and potentially catching fire. If you ever blow this fuse it can be replaced by the factory.
Cold Cranking Amps and Pulse Cranking Amps?
CCA stands for Cold Cranking Amps. The higher the number the bigger the kick your battery can give your starter motor. It is the maximum current a lead-acid chemistry battery can provide at 0 °F (−18 °C) for 30 seconds while maintaining a minimum voltage of at least 1.2 volts per cell (7.2 volts for a 12-volt lead-acid battery). This is the most widely used cranking measurement for comparison purposes of lead-acid batteries. However, lithium batteries generally stop working before the voltage drops to 7.2V so measuring the CCA of a lithium battery is not practical although some vendors do provide a theoretical ‘equivalent’ CCA as a comparative indication.
The problem is that different vendors derive their theoretical CCA ratings using different measurements and calculations and sometimes the marketing departments have influence! So the CCA ratings from different lithium battery manufacturers may not be directly comparable. Also for engine starting purposes, a 30-second discharge measurement is irrelevant. Normally we want an engine to start in the first 10 seconds of cranking!
PCA stands for Pulse Cranking Amps. Again the higher the number the bigger the kick your battery can give your starter motor. PCAs are usually measured over a short duration (typically between 3 and 10 seconds). Because the pulse time is comparable to the time it actually takes to start a bike, a PCA rating is a better measurement of the ability of a battery to start your vehicle. The problem is some vendors use a PCA pulse of just 3 seconds while other vendors use a PCA pulse of 10 seconds. A PCA of 200 over 10 seconds indicates a lot more power than a PCA of 200 over 3 seconds. So the PCA ratings from different lithium battery vendors may not be directly comparable.
Tritek batteries are rated at 10-second Pulse Cranking Amps (PCA)
Your supplier should be able to give you the best advice on what size battery you need for your bike.
Starting your bike in very cold weather ?
Each time your starter motor draws current through the battery it warms up the cells in the battery slightly. Remember a lithium battery’s internal resistance decreases with temperature. This is why on a cold morning on the third or fourth attempt at starting your bike the battery will actually spin the starter motor faster than the first attempt. If a bike with a lithium battery doesn’t spin your engine over quickly enough to start the bike on the first attempt wait a minimum 5 seconds to allow any temperature increase to spread through the cells and then thumb the starter again.
Is a measure of the storage capacity of a battery or how much charge it can hold. It is of little importance unless you operate the electricity of your bike while the engine is not running and charging the battery on your bike. If your motorcycle has current draw when the bike is not being ridden due to being fitted with an immobilizer system, clock, electronic dash, or other accessories that continue to consume your batteries capacity when the key is turned off then you may need to select a battery with a higher amp hour storage capacity or alternatively just connect the cable from the negative lead of your battery.
So in Summary is a modern Lithium battery or a good old lead acid battery best for you?
For racers with a good budget, the weight savings (Up to 4kg) make lithium batteries a done deal. How else do you lose 4kg for such a small price premium?…you can’t.
Yes, Lithium batteries are more reliable by a factor of several times. (Although it’s very early days yet our user poll shows that around 14% of lead batteries fail in the first two years and 25% have failed by the end of the third year. If that was the failure rate of a home appliance somebody would be getting nailed on Campbell Live! or having to answer some very hard questions from the Ministry of Consumer Affairs…perhaps they should be.
Even lithium batteries without an inbuilt BMS have failure rates well under 1/3 of lead acid battery failure rates.
Because a lithium battery has a very low self-discharge rate most customers never need to purchase a battery charger and this might be another cost benefit to owning a lithium battery. (Only 1 in 10 of our Tritek customers ever purchase a battery charger from us)
Unlike lead acid batteries, lithium batteries do not include sulfuric acid and do not produce explosive hydrogen gas.
Tritek lithium batteries have an inbuilt replaceable safety fuse that will blow in the event you have a short circuit on your bike.
When you consider that most people change bikes every three years then the very high failure rates (25% within three years) of lead-acid batteries become more acceptable (because the battery becomes someone else problem).
Unless you can swap your lithium battery from one bike to another, you could lose on the deal when the next owner gets your reliable long-life lithium battery and you may get a bike with an old lead-acid battery.