Image Video
Home  ::  Tune-Up and Maintenance  ::  Batteries  ::  PRE-ORDER ETA JUNE 24 Shorai Ultra Light High Performance Battery for BMW R1250GS/A LC R1200GS/A LC R1200GS/A OC F800GS/A F700GS F650GS - Heavy Duty LFX21A6-BS12

PRE-ORDER ETA JUNE 24 Shorai Ultra Light High Performance Battery for BMW R1250GS/A LC R1200GS/A LC R1200GS/A OC F800GS/A F700GS F650GS - Heavy Duty LFX21A6-BS12

PRE-ORDER ETA JUNE 24 Shorai Ultra Light High Performance Battery for BMW R1250GS/A LC R1200GS/A LC R1200GS/A OC F800GS/A F700GS F650GS - Heavy Duty LFX21A6-BS12
PRE-ORDER ETA JUNE 24 Shorai Ultra Light High Performance Battery for BMW R1250GS/A LC R1200GS/A LC R1200GS/A OC F800GS/A F700GS F650GS - Heavy Duty LFX21A6-BS12Send to a Friend
Item#   LFX21A6-BS12
Select Bike: 
Select Year: 

PRE-ORDER ETA JUNE 24 Shorai Ultra Light High Performance Battery for BMW R1250GS/A LC R1200GS/A LC R1200GS/A OC F800GS/A F700GS F650GS - Heavy Duty LFX21A6-BS12

The Shorai LFX21A6-BS12 combines an ultra-lightweight design with high performance. This BMW motorcycle battery weighs nearly eight pounds less than the R1250/R1200 OEM stock battery, coming in at only 3.04 pounds. Installing it will immediately improve your power-to-weight ratio so you get better acceleration, top-end speed and fuel mileage. Furthermore, this high-quality aftermarket battery can hold a charge for one year and provides faster cranking for better starts. In other words, a Shorai lightweight motorcycle battery will help you move quickly every second you're on your steed.

Switching batteries will provide additional advantages beyond performance. The Shorai BMW R1250/R1200 drop-in replacement battery uses lithium-ion prismatic cells, meaning the batteries contain no lead or dangerous acid. Each battery provides two to four times the service life of lead-acid batteries. The ultra-light Shorai battery is also protected by a two-year manufacturer's warranty. A military-grade carbon fiber composite case prevents the internals from being damaged in a crash.

This battery is smaller than your original battery, which is why high-density adhesive-backed foam sheets are included in the package. These can be trimmed and installed in the battery box in minutes to ensure a perfect fit. Cable connections can be made either at the tops or sides of the terminals to guarantee "as original" installations. When you open a Shorai LFX battery package you will also find a spare set of terminal screws, Shorai decals in various sizes, and the user manual. See our FAQ's below to learn more about Shorai exclusive eXtreme-rate LFX lithium technology and other ways this battery goes above and beyond the OEM model. We use Shorai batteries in our own BMW motorcycles and offer a 100 percent satisfaction guarantee that you'll be happy with one in your bike.


  • No more dead batteries. Holds charge for one year without maintenance.
  • Ultra-light battery is one-fifth the weight of lead-acid batteries on average.
  • Two to four times the service life of lead-acid batteries.
  • Drop-in replacement for your OEM battery.
  • Military spec carbon fiber composite case.
  • Faster cranking for better starts.
  • Super-fast recharge rate.
  • SAFE - no explosive gasses during charge, no lead and no acid.
  • Environmentally friendly - just discharge and dispose.
  • Includes battery, terminal screws, Shorai decals in various sizes and the user manual.
  • Includes industry-leading two-year manufacturer's warranty.


  • Voltage (V) 12
  • A/Hr PbEq 21
  • Cranking CCA (A) 315
  • Weight: 3.04 lbs. (1380 grams)
  • Max charge rate (A) 21

Frequently Asked Questions:

Q: What makes Shorai LFX different from other batteries?
A: Shorai LFX batteries contain Shorai-proprietary eXtreme-rate lithium-ion prismatic cells (chemistry LiFePO4). Shorai LFX batteries also contain no poisonous lead or dangerous acid and do not create explosive gasses during charge as traditional lead-acid batteries do. Compared to lead-acid, Shorai LFX lithium batteries are also extremely light, have much lower self-discharge rate, do not sulfate (i.e. do not degrade while sitting unattended) and are environmentally friendly.

While there are other companies now offering Lithium-Iron based powersports batteries, all except Shorai use cylindrical cells originally made for power tool applications. Such cells are inferior to Shorai Prismatic LFX for several reasons.

First, the cylindrical cells come only in one size, so the possible shapes and sizes of the starter batteries they make are very limited. As such, the battery fit in many vehicles may be poor or impossible as they are too wide or too tall. LFX prismatic cells, on the other hand, are rectangular packages which we can freely design and size according to the size requirements of the battery case. As such, Shorai LFX offers perfect drop-in fit in many vehicles. If the LFX is slightly smaller in one dimension, high-density adhesive-backed foam shims are included in the package. These can be applied to the battery box in a few minutes to ensure a perfect “as original” fit. No saws, cutting torches or duct tape are required!

Second is the pedigree. While power-tool cells may crank a vehicle successfully, they were not originally intended for the high current discharges in starter systems. As a result, cranking performance suffers compared to Shorai LFX, and the batteries will wear out more per start. By contrast, Shorai LFX is the result of years of our own research and development and is designed and produced in our own tightly controlled factory. Shorai LFX batteries have been used in some of the most extreme high-current projects in the world including autonomous aircraft, boats, and submarines, electromagnetic rail gun research and more. In short, LFX has been designed from the “ground up” to be a powersports starter battery with a long lifespan and high performance under a wide range of temperatures.

Finally, there is quality control. Every Shorai LFX is built in our own ISO 9000:2008-certified factory. The primary cell ingredients are sourced from Japan, which allows us to produce the most consistent and reliable cells. Then we do individual cell quality control and matching over a six-week period for every cell we make. This test period is two to four times longer than typical and is expensive for us. But it is worth it in terms of product quality in the long run.

Q: Why are Shorai LFX priced lower than other lithium starter batteries?
A: Shorai LFX batteries are produced exclusively in our own dedicated factory in large volume by an experienced production team. The resulting high yields reduce our costs, and the factory-direct connection allows us to offer pricing which is competitive with traditional OEM lead-acid batteries and lower than any other lithium-based alternative.

Q: How does the LFX "PBeq AHr" capacity rating compare to lead-acid AHr ratings?
A: First, we need to understand that the primary job of a starter battery is to flow a large current (amperage) for a short time in order to start a vehicle. In order to do that efficiently, the battery must have low internal resistance. Holding all other considerations equal, the larger the battery is in capacity, the lower the resistance, and the better able it is to crank a vehicle under high loads.

Lead-acid makers have therefore used AHr (capacity) ratings as shorthand to indicate cranking ability rather than a real usable capacity. The lead-acid capacity rating itself is based on a complete discharge at a low discharge rate. Under actual cranking conditions, they will deliver considerably less than spec capacity. Because lead-acid batteries begin sulfating when only a small percentage of the capacity has been used, and their internal resistance rises as they are discharged, the actual capacity which can be used may be as little as 20 percent of the mfg. rating. Discharge in excess will not only damage the lead-acid battery - it may not allow proper starting as voltage sags.

Shorai LFX is based on completely different chemistry. Not only does it have less than 1/3 the internal resistance per capacity than lead-acid batteries, it is also the ultimate "deep-cycle" battery. The internal "completely discharged" capacity of a Shorai LFX is 1/3 the rated "PBeq" capacity. For example, the LFX18 12V series has 6Ah cells internally. But the cells are capable of 90 percent discharge without damage while retaining more cranking ability.
As such, the usable capacity (or "reserve capacity") of an LFX18 12V battery is on or very near par with 18AHr-rated lead-acid batteries while providing superior cranking performance and a vast reduction in weight. The Shorai PBeq AHr (lead-acid equivalent) rating system, therefore, allows users to compare a very different technology from lead-acid but on a close apples-to-apples basis when making a choice.

Q: How does the LFX "CCA" cold-cranking rating compare to lead-acid AHr ratings?
A: CCA ratings are another way that lead-acid makers have tried to convey starting power. Unfortunately, their typical spec is based on a "half-nominal-voltage" delivery. That is, at their CCA spec, you can expect 7.2V delivered at best. And 7.2V isn't useful since you won't start a vehicle with it.

In any case, CCA ratings aren't about actually drawing that much current from a battery. The typical vehicle which uses a 200A CCA-rated battery, for example, will only draw 45-80A from the battery. What the CCA rating really intends to convey is how much voltage will be delivered. Higher CCA-rated batteries will deliver more voltage at the same actual cranking current. Our LFX is CCA-rated to deliver 9V for a five-second crank at the CCA-rated current. (In fact, our average voltage delivered will be even higher during a 30-second crank. But our CCA ratings are intended to indicate not only a measure of voltage at true cranking currents but also proper usage, which lead-acid batteries do not.)
At actual cranking currents - which are always well below CCA - LFX delivers up to two volts more than an equivalent CCA-rated lead-acid battery. Current alone won't start anything. It is the current multiplied by the voltage that does the work (watts). In reality, this means that you can multiply the LFX CCA rating by 1.5x to compare to a lead-acid battery CCA. For example, our 270A CCA LFX18 series provides about the same cranking voltage as a 405A CCA-rated lead-acid battery (from a quality lead-acid maker; some CCA specs we've tested on the cheapest lead-acid seemed to be plucked from thin air).

Q: Can I use lead-acid battery chargers or charger/tenders?
A: Yes. However, you may not use a charger/tender if it has an automatic "desulfation mode", which cannot be turned off. For example, we have confirmed with Deltran, makers of the "Battery Tender" brand, that their products do not have a desulfation mode and are therefore OK for use with Shorai LFX. But the best possible charger/tender for Shorai LFX is the SHO-BMS01. It uses the five-pin BMS port in the LFX batteries in order to monitor, diagnose and balance the individual cells during charge. It also has an optimized storage mode that will give the longest possible service life to your LFX.

If you are storing your vehicle or motorcycle and want to check the remaining capacity, or you're a racer with a constant-loss system, you'll want to know how resting voltage (i.e. with no load or load under 200mA) maps to remaining capacity. LFX batteries should be maintained such that 20 percent capacity remains at a minimum as best practice. Use a good-quality voltmeter to check remaining capacity and consider recharge whenever the battery capacity falls to about 50 percent remaining. Of course, if you get the Shorai dedicated BMS01 charger, you can just hit the "Store Mode" button and leave it to do the work for you.

Q: Should I use a battery tender?
A: The short answer is "only if you really need to". Most powersports enthusiasts have gotten used to hooking up a tender to their lead-acid batteries all the time. Shorai LFX has much slower self-discharge than the best lead-acid does (1/6 to 1/7, on average). They also do not sulfate as capacity drops, and they are the ultimate "deep-cycle" battery, which means that they can still crank your vehicle even if the remaining capacity is quite low. Therefore, most riders will not need to use a tender at all. Even a charger or tender uses energy you have to pay for, and there is always the possibility that a charger or tender can fail in some way. So if they are not really needed, the best practice is to not use one.

A fully charged LFX can sit for a year or more and still retain adequate starting capacity without damaging the battery. As such, any vehicle which has no current flowing when the key is off should never need a tender. At most, it should be charged every 6 to 12 months depending on the average storage temperature (cool storage is much better for any battery). Many older vehicles and most dirt bikes/ATVs fall into this category.

Newer vehicles may have a significant draw even when the key is off to maintain clocks, computers, etc. In this case, we expect that a few hours of riding per month will be all that is needed to avoid tending. If you know that you will go a number of weeks or months without riding, you can either attach a tender or disconnect the negative cable from the battery. In any case, you may use the recommended voltage chart and an accurate voltmeter during storage. Consider recharging when the battery is around the 50 percent capacity remaining mark or below.

Q: I hear that lithium batteries crank poorly when it gets cold. Is that right?
A: Lithium batteries do increase in resistance more as temperature drops compared to lead-acid. However, they also react to cranking under cold conditions in a much better way. Lead-acid will increase resistance on each subsequent cranking attempt until it won't turn over. If your LFX fails to start the engine on first crank, that first crank has warmed the battery, and the second attempt will be much stronger, and so on until you get a good start.

Shorai LFX is much better in cold weather conditions than other brands of lithium starter batteries due to our eXtreme-rate formulation with low resistance. Down to about 20 degrees Fahrenheit (-7C), most users find that they can start normally on the first crank. If your headlight comes on at key-on, it is good for the batteries to flow some current before cranking in cold weather. The suggested headlight-on time before cranking depends on the temperature. If starting at 40 degrees (5C), 30 seconds will help wake the battery and increase cranking performance. If at 0 degrees (-17C), leave the lights on for 4-5 minutes before cranking. The result will be a better first crank and longer battery life. Any other accessories that can be turned on before cranking can also be used for this purpose, such as heated gear, radio, etc.

Q: Can Shorai LFX be fully discharged and then disposed in regular garbage?
A: That depends on your municipal regulations. Shorai LFX meets the European RoHS standards for environmental health and contains no lead. Check with your local authority to see if LiFePO4 batteries are allowed. If so, fully discharge the battery before disposal, which you can do by using a 12V light bulb until no longer lit. We expect that there will also be recycling available in some locations and more coming in the years ahead.

Q. Can Shorai LFX be mounted in any position?
A: Yes. There are no liquids in the LFX batteries.

Q: How long will my LFX battery last?
A: That depends on many factors. A lead-acid battery may last only a few weeks under the worst conditions and about seven years under the best (top-quality brands with regular use). In between, you will find a wide variety of user experiences. Our research indicates an average of about 2.5- to 3-year lifespan for lead-acid. Under the same average usage conditions, we expect Shorai LFX to last roughly double at 5 to 6 years. Under ideal usage and storage conditions, we expect 8 to 10 years to be achievable. Due to their lack of sulfation and slow self-discharge, Shorai LFX increases battery life most for users who sometimes store their vehicles for weeks or months at a time and don't want to or can't use a battery tender.

Q: The terminal screws seem too short for my vehicle, which has thick cable eyelets. What can I do?
A: First, see the install guides on our site. They show how to use the foam padding (5mm shown, but 10mm sections may be even better) on the nut bottoms so the nuts rise to the top of the terminals. This helps the screw threads catch the nut. If that isn't enough, note that the screws are M5x0.8 pitch. Any hardware store should have a selection of those, so take a terminal screw to compare and get slightly longer screws, as well as some washers to make sure that the screw doesn't penetrate "too far" when tightened down.