Free Economy ShippingProduct Specifications for Shorai LFM21L7-BS12 Lithium-Iron Powersport Battery with BMS
| BM Part #: | LFM21L7-BS12 |
|---|---|
| Battery Polarity: |
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| Voltage: | 13.2 Volt |
| Cold Cranking Amps: | 315 CCA |
| Capacity: | 7 Ah |
| Energy Capacity: | 92.4 Wh |
| Type: | Lithium Iron |
| Length: | 5.83" |
| Width: | 3.23" |
| Height: | 4.72" |
| Shipping Weight: | 3.03Lbs |
| Warranty: | 1 Year Free | 5 Year Prorated Factory Direct |
- 315 Cold Cranking Amps: Delivers reliable, consistent starting power in cold weather without voltage drop-off as the battery ages.
- Weighs Just 2.81 lbs: Up to 70% lighter than a comparable lead-acid battery, reducing overall bike weight for better handling and control.
- Integrated Sentry BMS: Built-in Battery Management System automatically disconnects terminals if voltage drops too low, preventing over-discharge damage.
- Holds Charge Up to a Year: Low self-discharge rate keeps the battery ready after months of off-season storage with zero maintenance needed.
- Direct YTX14L-BS Replacement: Case Type 7 dimensions fit most BMW K and R-series battery compartments with foam spacers included for a secure fit.
- No Sulfation: LiFePO4 chemistry won't degrade while sitting idle, unlike lead-acid batteries that lose usable capacity over time.
Product Description
You invested in a BMW for good reason. Whether you're putting miles on an R1200RT, carving through twisties on a K1200RS, or touring on a K1600GT, the last thing holding you back should be a bloated, unreliable lead-acid battery. The Shorai LFM21L7-BS12 is a lithium iron phosphate (LiFePO4) powersport battery built to match the performance level of your bike, with 315 cold cranking amps in a package that weighs just 2.81 lbs.
That's up to 70% less weight than lead-acid. For riders on touring bikes like the K1200LT or K1300GT, where every pound matters, that difference is real and noticeable in how your bike handles and responds.
Stop Fighting Cold Starts and Storage Dead Batteries
Lead-acid batteries lose voltage as they discharge, which means weaker cranking power as the battery ages and even weaker performance in the cold. The LFM21L7-BS12 delivers consistent voltage from the first start to the last, so your engine fires up confidently whether it's March or mid-July.
Parked for the season? This battery holds its charge for up to a year without maintenance. It won't sulfate while sitting the way lead-acid does, so you're not gambling on whether it'll crank when spring finally arrives.
Built-In Protection That Watches Your Battery 24/7
The integrated Shorai Sentry Battery Management System (BMS) monitors voltage continuously. If a slow parasitic draw pulls the charge dangerously low while your bike sits, the BMS automatically disconnects the terminals before any permanent damage can occur. No guesswork, no intervention required on your part.
Drop-In Ready for BMW and YTX14L-BS Applications
The Case Type 7 footprint (5.83" L x 3.23" W x 4.72" H) fits directly in place of a YTX14L-BS battery. Foam spacers are included if your battery box needs a snugger fit. No changes to your charging system required.
Ready to stop babysitting your battery? Order the Shorai LFM21L7-BS12 today and get free standard shipping to the contiguous 48 states.
What's the difference between the "equivalent" and "Actual" amp hour capacity?
The manufacturer includes the "equivalent" (PbEq, "lead equivalent") rating to show a more apples-to-apples comparison between the lithium chemistry and the lead-acid battery that you're likely replacing.
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. And 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% of the mfg. rating. Discharge in excess will not only damage the lead-acid battery, it may not allow proper starting as voltage sags.
For example, the Shorai LFM18 12V series have 6Ah cells internally. But, the cells are capable of 80% discharge without damage while still retaining more cranking power. As such, the usable capacity (or "reserve capacity") of an LFM18 12V battery is very close to 18Ah-rated lead acid batteries, while also providing superior cranking and huge weight reductions.
Cold Weather Performance Expectations
Down to about 20° Fahrenheit (-7°C) most users find that they can start normally on 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°F/5°C, 30 seconds will help wake the battery and increase cranking performance. If at 0°F/-17°C, leave the lights on for 4~5 minutes before cranking. The result will be a better first crank, and longer battery life. If the engine fails to start on first crank, that first crank has warmed the battery, and the second attempt will be much stronger. Other accessories that can be turned on before cranking can also be used for this purpose, such as heated gear, radio, etc... Insuring that the battery is fully charged after storage also improves first-start performance in cold weather.
Warranty Terms
Shorai offers a Limited, Pro-Rated Five-Year Warranty for Shorai batteries, for defects in material and/or workmanship, pertaining to sales originating and delivered within the United States.
The warranty is divided into three periods from date of purchase within the USA, as follows:
All warranty claims for products purchased and delivered within the United States are handled directly by Shorai Service LLC. only. Battery Mart can only provide information for getting in contact with Shorai for warranty claims. See the Warranty Form for online submission of warranty claims, and to get your Return Merchandise Authorization (RMA#) assignment. Replacement batteries are to be issued by Shorai and sent directly to the customer. No dealership is authorized to issue a replacement battery without prior written authorization from Shorai.
Please do NOT return any product to Shorai without an RMA# or before Shorai has contacted you. In many cases issues can be solved prior to return.
Conditions which will void warranty
- Opening the battery case will void the warranty.
- Applications Not listed on the Shorai website product finder such as: Aircraft, Automotive, Go Karts, Motive power (Shorai as main power source, not engine starter).
- Over-voltage charging, or other error by charger or user setting of charger.
- Use in excess of cranking (CCA) specifications (incorrect use in custom vehicle, etc).
- Short circuit of main terminals or BMS port.
- Short circuit caused by improper installation.
- Improper connections to the 5-pin BMS port.
- Over-discharge (i.e. resting voltage allowed to fall below 12.8V/6.4V for Lfx 12V/6V types).
- Physical Damage to the battery occurring after purchase (impact, etc).
For custom vehicles if you have a stock motor pulled from another vehicle, then you can use our battery finder to select the battery that the motor came from as long as the starter gearing is the same. If you have any other questions, please give us a call and we will assist you.
Frequently Asked Questions
What's the difference between the LFM21L7-BS12 and the old LFX21L7-BS12?
A: They're functionally the same battery with one important upgrade. In October 2024, Shorai officially rebranded its lineup from "LFX" to "LFM" to formally recognize the integrated Battery Management System (BMS), which had quietly been included in production since mid-2022. The internal cells, dimensions, voltage specs, and cold cranking amps are all identical between the two. The part number change exists simply to make it easy to confirm your battery includes BMS protection. If you've been searching for the LFX21L7-BS12, the LFM21L7-BS12 is its direct, current replacement.
Which motorcycles is the LFM21L7-BS12 compatible with?
A: This battery is sized and specified for a wide range of BMW models, including the R1200C, R1200RT, K75 series, K1100RS/LT, K1200RS/GT, K1200LT, K1300GT, K1600GT/GTL, and pre-2005 R1100 and R1150 series. It also fits any application that accepts a Case Type 7 or YTX14L-BS battery. Not sure about your specific model? Use Shorai's online fitment tool or reach out to our team and we'll help you confirm.
Will this battery work with my stock BMW charging system and battery tender?
A: In most cases, yes. Your charging system output should measure between 13.6 and 14.4 volts at 2,000 RPM. If you use a battery tender, verify it does not have an automatic desulfation mode that cannot be disabled, as this mode can damage lithium batteries. Most current lithium-compatible "smart" chargers work fine, but always confirm before connecting.
Does the LFM21L7-BS12 need to be charged before installation?
A: Yes. Shipping regulations require lithium batteries to ship at approximately 30% capacity. Shorai recommends charging the battery with a lithium-compatible charger before first use. We recommend the Battery Tender 022-0209-DL-WH charger for this battery.
