Free Economy ShippingProduct Specifications for Shorai LFM21A7-BS12 Lithium-Iron Powersport Battery with BMS
| BM Part #: | LFM21A7-BS12 |
|---|---|
| Battery Polarity: |
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| Voltage: | 13.2 Volt |
| Cold Cranking Amps: | 315 CCA |
| Capacity: | 7 Ah (21 Ah Equivalent) |
| Type: | Lithium Iron |
| Length: | 5.83" |
| Width: | 3.23" |
| Height: | 4.72" |
| Shipping Weight: | 4.00Lbs |
| Warranty: | 1 Year Free | 5 Year Prorated Factory Direct |
- Ultra-Lightweight Construction: Weighs just 2.81 lbs, saving roughly 7 lbs over a comparable lead-acid battery for noticeably better handling and agility.
- 315 CCA Cranking Power: Puts out 315 cold cranking amps with a 21Ah lead-equivalent capacity rating in a compact, right-positive case.
- Shorai Sentry BMS Included: The integrated Battery Management System monitors charge levels and disconnects terminals to prevent harmful deep discharge automatically.
- LiFePO4 Chemistry: Contains no lead, no acid, and produces no explosive gases during charging, making it safer and significantly more environmentally friendly.
- Military-Grade Carbon Fiber Composite Case: Shorai's proprietary housing handles the vibration, heat, and impact demands of powersport riding mile after mile.
- 5-Year Prorated Factory Warranty: Includes 1 year of full replacement coverage plus up to 5 years of prorated warranty support handled directly by Shorai.
Product Description
Are you tired of a heavy, high-maintenance battery slowing you down? The Shorai LFM21A7-BS12 is a 13.2V LiFePO4 lithium powersport battery built for riders who refuse to carry unnecessary weight. It fits directly into your OEM battery tray and works with your existing charging system — no modifications, no compromises.
This battery sees frequent use in machines like the Honda VFR800 Interceptor, Kawasaki Ninja ZX-12R, Triumph Speed Triple (955cc), and Yamaha FJR1300 — bikes where dropping weight from the chassis makes a tangible difference in cornering and balance.
Your Last "Dead Battery" Season
One of the most common frustrations with lead-acid batteries is sulfation — the slow capacity loss that happens when a battery sits partially discharged. Pull your bike out after winter storage and you're often left with a sluggish or completely dead battery. Lithium iron phosphate chemistry doesn't sulfate.
Store the LFM21A7-BS12 for months, and it holds onto its charge far better than any lead-acid equivalent. The built-in Sentry BMS adds another layer of protection for long storage periods, watching voltage levels and stepping in before the cells can be harmed by deep discharge.
Cold Weather Performance
In cold conditions, lithium batteries benefit from a brief warm-up before cranking. At 40°F, running your headlight or accessories for 30 seconds before the first start helps the battery perform at its best. At temperatures near 0°F, give it 4-5 minutes. If the first crank is sluggish, that crank itself warms the battery — the second attempt will be noticeably stronger.
A True Drop-In Replacement
The LFM21A7-BS12 installs with no wiring changes and no charging system upgrades, as long as your vehicle's charging system outputs between 13.1 and 15.2 volts — which virtually all modern powersport systems do. If the battery is slightly smaller than your OEM tray, Shorai includes adhesive-backed foam shim sheets in the box. Trim them to fit, apply them in minutes, and you have a solid, insulated fit.
- Terminals support connections from the top or side for flexible cable routing
- Bolt size: 10mm bolt with 5mm threads
- For powersport applications only — not for automotive use
Ready to stop replacing dead batteries and start riding lighter? Order the Shorai LFM21A7-BS12 today with free standard shipping to all 48 contiguous 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 LFM21A7-BS12 and the old LFX21A7-BS12?
A: They are functionally the same battery. The LiFePO4 cells, case dimensions, voltage, and CCA specs are identical between the two. In mid-2022, Shorai started adding a Battery Management System (BMS) to all batteries but didn't update the part number at that time, which led to customer confusion about which batteries had BMS protection. In October 2024, Shorai introduced the "LFM" naming convention specifically to identify current-generation batteries with the Sentry BMS. If you've been ordering the LFX21A7-BS12, the LFM21A7-BS12 is your exact current-generation replacement — same fit, same power, now clearly identified as BMS-equipped.
What motorcycles is the LFM21A7-BS12 compatible with?
A: The LFM21A7-BS12 is a direct replacement for batteries with OEM part numbers YTX14-BS, YB16-B, YB16B-A, YB16B-A1, GYZ16H, HYB16A-AB, and GT14B-4. This covers a wide range of motorcycles and powersport vehicles from Honda, Kawasaki, Yamaha, Suzuki, Triumph, BMW, and more. Always confirm your specific year and model using Shorai's Battery Finder tool on their website before ordering, and verify that your charging system outputs between 13.1 and 15.2 volts.
Can I use my existing battery charger or tender with this battery?
A: Yes, in most cases. The LFM21A7-BS12 is compatible with standard lead-acid and AGM chargers. The one critical exception: do not use any charger that has an automatic "desulfation," "repair," "recondition," or "recovery" mode that cannot be turned off. These modes are designed for lead-acid chemistry and can damage lithium cells. Battery Tender brand chargers do not include a desulfation mode and are confirmed safe for use with Shorai batteries. If using a smart charger for long-term storage maintenance, Shorai recommends disconnecting and reconnecting it every 7-10 days.
What if the battery is smaller than my original battery tray?
A: Shorai includes high-density, adhesive-backed foam shim sheets with every battery for exactly this situation. Trim them to the dimensions you need, apply them to the inside walls of your battery box, and the battery will sit snugly with added vibration dampening and thermal insulation. Terminal connections can be made from either the top or the side of the terminals, giving you flexibility with cable routing during installation.
