What you need to know about lithium motorcycle batteries

What you need to know about Lithium Motorcycle batteries before you buy one.

What are the advantages of Lithium batteries?

  • Extremely light weight! For example a typical 16 amp/hour battery weighs 5kg. A replacement Ultrabatt Lithium battery weighs an amazing 860 grams 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 LiFePO4 lithiium 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 a very long service life compared to lead acid batteries. Target life for 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 16 a/h yellow Motobatt battery above is from a Ducati 900SS and weighs over 5kgs and is rated at 200 Cold Cranking Amps. The Ultrabatt Lithium 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

Charge times?

LiFePO4 (especially those with built in Battery Management Systems) have extremely fast charge 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 Ultrabatt UB3000 3 amp charger in just 1-2 hours. By comparison a discharged lead acid battery will take over 12 hours to charge to full capacity.

Do they really have superior reliability and a very long service life compared to lead acid batteries?

Customers should expect a lithium battery with an inbuilt BMS to last 5 to 10 years. By comparison a recent user polls showed that over 21% of lead acid batteries fail in the first two years and 37% had failed within just 3 years! By comparison warranty records show the failure rate for Ultrabatt's LiFePO4 motorcycle batteries was less than 2% in the first two years. (Ultrabatt's confidence is demonstrated by one of the industries only, full value 2 year replacement warranties). 


 What about self-discharge rates? 

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 sit on a shelf uncharged for six months and still be able to start your motorcycle. For this reason most customers do not bother buy a smart battery charger/tender for their lithium batteries.

What is the cost comparison of legacy lead acid batteries Vs Ultrabatt Lithium batteries?

Motorcylists 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 an Ultrabatt Lithium battery that will last between 5 and 10 years. Especially if they also cost in the expense of purchasing a smart charger, that costs as much as the purchase price of a lead acid battery

Many owners will discover an Ultrabatt LiFePO4 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 int to their new bike. (This is only possible if the new bike and the old bike use the same size battery of course.)

Are there issues with Lithium batteries I should know about?

Yes! FastBikeGear's product manager, Liam Venter has a background in electronics (New Zealand Certificate of Engineering, telecommunications/radio/electronics). We spent some time researching LiFePO4 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 potential and costly issues thhat 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 approachh 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 overheaating in the case of a short circuit.

As you will see by incorporating an inexpensiver BMS (Battery Managment System) and intelligent design all of these factors can be mitigated.

Are all Lithium batteries are 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 that
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 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 on to the cells. Both methods are potentially problematic when subjected to vibrations and impacts and have stopped at least one lithium battery supplier in New Zealand from recommending their lithium batteries for use in these types of vehicles. 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 was one of the key factors why we didn't jump into the Motorcycle Lithium battery market. Ultrabatt addressed this issue by using laser welding technology which is extremely fast and pinpoint 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 descibe 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 to far. The latest generation of cylindrical LiFePO4 cells are much more robust in this respect. It is still a good idea to never allow your battery to completely flatten in order to maximise the 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 it's 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 it's self and potentially generate enough heat to damage your motorcycle.

Modern lithium batteries such as the Ultrabatts 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 Ultrabatt batteries sold in New Zealand since 2010 have had internal fuses.

Never assume your battery has internal short ciruit 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 bikes main power fuse (normally situated on the positive power lead right next to your battery) or fuesable 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 it very important that when wiring in accessories, heated grips, GPS units, radar detectors, etc that the external fuse is not bypassed. Of course it its not possiible to bypass and internal fuse.

Short cell life due to the individual cells within the battery being either under or over charged.

If LiFePo4 batteries are charged without a BMS (Battery Management System) 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 european manufactured lithium batteries now have a BMS built into the battery to protect it and ensure it is being properly chharged while you ar riding the bike.

Manufacturers that still do not make batteries with a built in BMS recommend that you also purchase an external mains powerd 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 baancing and other BMS functions while you are riding the bike (which is of course when thhese features are needed most).

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 LiFePO4 batteries need cell balancing during the charging process?

  • Cells in all types of batteries (lead acid, nickle metal hydroxide and Lithium) cells that consistently sit at less than full charge will last years less than cells that are consistenltly maintaind near full charge. If you start with a 10 year target life and then just lose a couple of years off 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.

  • Likewise dells in all types of batteries (lead acid, nickle metal hydroxide and Lithium) cells that are consistently over charged also will last years less than cells that are consistenltly maintaind near the correct full charge. If you start with a 10 year target life and then just lose a couple of years off 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 to 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, it's higher resistance slows down it's 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 LiFePO4 battery the exact opposite occurs. As each cell in a LiFePO4 charges, the internal resistance of the cell decreases. If one cell begins to charge faster than the others, it's resistance decrease. The lower resistance further speeds up it's charge rate in comparison to the other cells which further decreases it resitance and further increases it's charging rate. Hence cells in Lithium batteries do not automatically balance with each other as they charge. One cell can be fully charged and the one next to This is a prblem because cells in all types of batteries (lead acid, nickle metal hydroxide and Lithium) 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 system this occurs every moment the battery is being charged while you are riding the bike.

Ultrabatt were the first lithium motorcycle battery manufacturer to eliminates the extra expense of having to purchase an external mains powered BMS charger and eliminated the hassle of having to regularly re balance the charge of individually cells. They did this by incorporating a muliti-function microprocessor controlled BMS system inside the battery,

With an inbuilt BMS you can charge your lithium battery directly from the bikes 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 a road bike as a plug and forget replacement battery that will do it's 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 New Zealand 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 acrue the cost savings?

Why can't Lithium batteries be charged by a standard automotive workshop trickle charger? Well actually they can be as long as the with a charger that meets your lithim battery suppliers guidelies. The guidelines for the older Ultrabatt batteries UB200, UB400 and UB600) are different from the guidelines for the new batteries. You should check the guidelines with your batttery supplier to ensure that you do not damage your lithium battery or void your warranty.

  1. The best way to maintain the charge in a lithium battery is to ride your bike and let your bikes charging circuit and the BMS in the battery do their thing. Before installing your new Ultrabatt 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.

  2. Do not use smart charger that has a Desulphation stage!

  3. 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 cautomotive 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 mighte survive charging rates over 15 volts for short periods of time you could will probably be unknowing be shortening it's lifespan. We believe it is preferential to maximising the lifespan of your lithium battery,  that you use a lithium mains charger supplied by your battery manufacturer.

  4. It is common practice to leave a lead acid battery connected to smart charger when not in use to extend the life of the batery. 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 a lead acid battery. 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 mains charger. Once your mains charter detects the battery is 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 unneccesarily. Once your battery is charged we recommend you turn it off and disconnect it from the battery.

  5. 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 you motorcylcle - or store the battery separately from motorcycle. It is a good idea to occassionally measure the voltage of your battery while in storage. If you wish to charge you battery while in storage we recommend taking your bike for a short run or periodically using an Ultrabatt UB3000 charger. These can be purchased from your Ultrabatt supplier.

Please note Ultrabatt batteries are equiped with an internal fuse for your safety. In the event that you have a high current short this fuse will blow to prevent the battery overheating and potentially catching fire. If you ever blow this fuse it can be replaced by the factory.

How do I select the correct size battery for my bike?

You should select a replacement battery that has at least the same or more CCA as your existing battery. Be aware that because there are practical issues in testing the CCA rating of a Lithium battery, many lithium battery manufacturers will advertise a CCA rating it is actually more likely to be a PCA (Pulse Cranking Amps) rating.  If you live in a location where the temperature routinely drops to zero degrees celsius or below you should condider choosing the next size up battery.

  • The Ultrabatt UB200 (120 PCA) is designed for 125-250cc bikes. It is also ideal for Moto2 bikes and other 600cc racing bikes not fitted with a starter motor.

  • The Ultrabatt UB400 (240 PCA) can be seen as a replacement for 7-14 A/h lead/acid batteries. The UB4000 is suitable for 600cc-1000cc, 4 cylinder bikes and V-twin bikes greater up to 850CC.

  • The Ultrabatt UB600 (360 PCA) can be seen as a replacement for all 14-20 A/h lead/acid batteries. Suitable for most 4 cylinder bikes greater than 1000CC and V-twin bikes greater up to 1400CC.

For race use you may be able to use a battery a size smaller than the above recommendations. Please contact us to discuss.

For full performance specifications please see the relevant product listing on our wb site. Using a battery that is underated for the task may well cause the internal fuse to blow to protect the cells within that battery from damage that could effect their life span.

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). IThis 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 comparitive 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 stand for Pulse Cranking Amps. Again the higher the number the bigger the kick your battery can give your starter motor. PCA's 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 abiity 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.

Ultrabatt 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 you bike.

What else do I need to know about caring for your Ultrabatt battery?

Not a lot actually but the following should be useful and perhaps even interesting information.

Starting your bike in very cold weather?

Each time your starter motor draws current throught 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.

Amp Hours?

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 electrics 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 continues 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 good old lead acid battery best for you?

  1. For racers with a good budget the weight savings (Up to 4kg) make ltihium batteries a done deal. How else do you loose 4 kgs for such a small price premium?...you can't.

  2. 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.

  3. Even lithium batteries without an inbuilt BMS have failure rates well under 1/3 of lead acid battery failure rates.

  4. Because a lithium battery has 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 Ultrabatt customers every purchases a battery charger from us)

  5. Unlike lead acid batteries, lithium batteries do not include sulfuric acid and do not produce explosive hydrogen gas.

  6. Ultrabatt lithium batteries have an inbuilt replaceable safety fuse that will blow in the event you have a short circuit on your bike. ($2 fuse replaced via access hatch under sticker).

  7. 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 becomes more acceptable (because the battery becomes someone else problem).

  8. 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.



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