Shorai LFX Lithium Battery

What it is

• A light-weight Lithium-Ion Battery.

The Shorai LFX battery is a lightweight Lithium-Ion replacement battery for most modern dirt bikes. Using a Shorai-proprietary eXtreme-Rate Lithium Iron prismatic cells (chemistry LiFePO4) the battery is claimed to be up to three pounds lighter than standard lead acid batteries. LiFePO4 batteries are different than more typical LiCO2 type batteries used in consumer electronics as they have longer lifetime and can deliver power at a better rate even though they have a lower energy density. LiFePO4 is also safer and more stable under most circumstances.  The Shorai battery is typically smaller than the battery it replaces and comes with adhesive foam pieces to shim it to the right size for fitment in battery trays. The terminal mounts are in the standard positons.

How it works

• Works just like a battery should--you shouldn't even think about it.
• 1.2-pounds lighter than stock.
• Handled the use and misuse we gave it like a champ.

A battery is an energy storage device you’d like to never have to think about. But you do every time one goes dead, or you have an issue with one. Lithium-Ion type batteries started getting popular in motorcycles about five years ago. They have become more popular ever since, largely because they are much lighter than Lead Acid batteries and they last longer in storage if there is not a drain on them.

Shorai has been in the game since the beginning and has grown quite a bit in that short time. I have had some of their original batteries in a few of my bikes for over four years now and they are still cranking strong as if they were brand new. Additionally the newer ones work just like a battery should. They start my bikes up and keep the lights and things like heated grips, GPS units and cooling fans running when needed. Frankly, there is little difference when compared to the function of a “normal” battery but they are some differences and we'll detail here.

First is weight. For the 2014 KTM 350EXC we tested on, the weight difference was 1.2 pounds lighter compared to the standard YTX-5L. At 1.5 pounds in total weight, that is a pretty good reduction in highly placed mass on the motorcycle. Aside from some exhaust systems and tires, there are not many ways to drop weight so easily.

The second difference is that a Li-Ion battery can take a little time to warm-up and come to full cranking power. Especially when it is very cold outside, say near freezing, the battery actually has to warm itself. This can be accomplished by turning on the key and having a light on the bike come on or simply with a quick push of the starter button to draw some current. Lithium-ion batteries then self-warm and will give off more cranking amps unlike a lead-acid battery that will have all its power from the first push on the starter button. The Shorai never had an issue starting the KTM 350 even in freezing conditions. Once in use it has full boost available till it cools down and is out of use for some time.

Instillation was simple with a few pieces of the included adhesive-backed foam cut and attached to make the Shorai battery the same physical size as the standard one. Then it fit snuggly in the battery box and the cables attached as normal. Shorai Batteries require a charging system output of 13.1 volts or higher at idle, and must not exceed 15.2 volts at maximum output which is fairly normal for most battery-equipped dirt bikes. It sits at a voltage of roughly 13.1-13.2 volts and even after a couple of months of sitting it did not drop at all. Under normal usage, or at least getting some use once a month, you should never have to consider the battery. If you plan on storing it, Shorai recommends its $89.95 BMS-01 charger which has a number of modes and can both balance and provide a storage charge for the battery.

In use the battery performed flawlessly. Even after we left the key on where the light drained the battery dead. Li-Ion batteries have a way of shutting off where the voltage drops to a point where the conductivity no longer exists. Then you must give the battery a charge to bring it back to life, which we did by attaching jumper cables and then starting the bike, where the bike’s charging system took over and had the battery charged and starting the bike again in a matter of minutes. As an acid test, we did over 100 starts with the Shorai attached to a voltmeter and the battery only dropped to 12.5-volts constant and charged back up in just a minute of running time holding 13.1-volts and held it.

Shorai’s customer service has improved quite a bit in the past few years and they can help you if you have questions or issues with your battery. History has shown that over charging or parasitic drains on the battery are the two most common problems with Lithium batteries.  For sure they do not like excessive heat, which in standard locations on most dirt bikes is not an issue. Over time with normal usage and the unintentional misuse too, we will say the Shorai lasts longer than lead-acid batteries but not the double or triple lifespan some may suggest.  At roughly three-times the cost of a standard battery the Shorai is a bit of an investment. For some the weight reduction is easily worth it. Lately the quality of lead-acid batteries seems to have dropped off to a point where getting over two-years out of a battery becomes lucky. Our experience with Shorai bateries has been that the quality has improved over time and with a couple bikes going on five years, they are definitely worth a try.

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