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SigmasTek  |  SKU: BW-8812

Invacare M61 High Performance Wheelchair Replacement Battery

Sale price $214.25 USD Regular price $280.53
Shipping calculated at checkout.

➤ Factory fresh replacement batteries for Invacare M61 wheelchair

➤ 100% compatible with Invacare M61 units requiring SP12-35 NB (12V 35AH)

➤ AGM technology with valve regulated, spill-proof design for safety

➤ Deep cycle use ensures long-lasting power and reliable performance

➤ U.L. recognized, CE certified, and backed by a 1-year warranty


📦🚀 FAST SHIPPING: Usually ships same day if ordered before 2 PM EST

⚠️ Quick Reminder

🔹 Please ensure the original battery model number is listed in our product description and that your device model number matches for compatibility.
🔹 We only supply the batteries shown in the images. Device images are provided for reference only.

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Battery Care Guide

Battery Usage and Maintenance Guidelines 🔋

Please read the following instructions carefully before using your new battery. Proper adherence will help ensure optimal performance and extended service life.

1. Cordless Phones, PDAs, and Power Tools (NiMH, NiCd, Lithium-Ion) 📱

Initial Charge

  • Fully charge the battery overnight prior to first use.

Conditioning (First 2–6 Charge Cycles)

  • Operate the device until the battery reaches approximately 20% capacity.
  • Avoid premature recharging.
  • Do not allow the battery to fully discharge during the initial cycles.

Post-Conditioning

  • Recharge the battery only when necessary.
  • These batteries are capable of approximately 500 charge cycles:
  • Once daily → ~500 days
    Twice daily → ~250 days
    Note: Even a partial recharge is considered a full cycle.

2. Sealed Lead Acid (SLA) Batteries 💡

  • No conditioning required.
  • Maintain the battery in a fully charged state; avoid complete discharge.
  • Capable of 300–400 charge cycles.
  • Expected service life: 2–3 years, depending on usage conditions.

3. Laptop Batteries (Lithium-Ion) 💻

Initial Charge

  • Fully charge the battery overnight prior to first use.

Conditioning (First 2–6 Charge Cycles)

  • Charge fully, then discharge to approximately 20% capacity.
  • Avoid complete discharge, as some devices may not detect a fully drained battery.

Post-Conditioning

  • Minimize frequent plugging and unplugging.
  • Allow the battery to discharge moderately at least once per month to maintain optimal performance.
  • Occasional cycling is recommended to sustain battery health.

Professional Recommendation

Adhering to these guidelines will enhance battery longevity and ensure reliable performance.

For further assistance regarding your battery or order, our customer support team is available to provide guidance.

Delivery and Shipping

Everything You Need to Know About Shipping with BatteryWeb (USA)

We know reliable delivery matters when you need power fast. Here’s how BatteryWeb makes shipping easy across the USA:

🚚 Shipping & Delivery

Most orders ship next business day (some products like sealed lead acid may take a little longer).

Same-day shipping available if you order before 11:59 AM (delivery depends on the carrier).

We ship nationwide using FedEx, UPS, USPS, DHL, and regional ground carriers.

Shipping costs are calculated automatically at checkout based on weight, distance, and carrier.

Transit times shown are estimates only (business days, no weekends/holidays).

🌍 Shipping Restrictions

Lithium batteries cannot be shipped by USPS or air. They must go via FedEx Ground, UPS Ground, or DHL Ground.

PO Box deliveries are only available via USPS.

At this time, we do not ship lithium batteries to Puerto Rico. NiMH, NiCd, and Alkaline can be shipped.

📦 Important Notes

Double-check your shipping address! If an incorrect address is used and the order is returned, re-shipping costs are the buyer’s responsibility.

If a product is temporarily out of stock, we’ll notify you right away with the expected restock date—or issue a refund if you prefer.

💲 Currency & Pricing

All prices are shown in USD.

Orders shipped outside the USA may be subject to local taxes, customs fees, or import duties. These are the buyer’s responsibility.

⚡ At BatteryWeb, we’re committed to getting your batteries delivered quickly, safely, and affordably—so you’ll always have the power you need, when you need it.

Disclaimer

⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.

🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

🔹 Our products are generic replacement parts and are not affiliated with, endorsed by, or manufactured by the original equipment manufacturers (OEMs).


Volts & Amps

12 Volts | 35 AH

Terminal Type

Nut & Bolt

Replacement Invacare M61 Wheelchair Battery — Compatible with Invacare M61 (SP12-35 NB, 12V 35AH)

Upgrade your mobility with this factory-fresh replacement battery engineered specifically for the Invacare M61. Designed for reliable performance, these Invacare M61 replacement batteries deliver the deep-cycle capacity and safe construction you expect from a high-quality power source. If your Invacare M61 requires two SP12-35 NB units, these 12V 35AH batteries are 100% compatible and provide dependable, long-lasting battery power for daily use and extended outings.

Key Specifications

  • Brand: SigmasTek
  • Compatible Model: Invacare M61
  • Battery Model: SP12-35 NB
  • Voltage: 12 Volts
  • Capacity: 35 AH
  • Quantity Required: 2 batteries (per wheelchair)
  • Technology: Absorbent Glass Mat (AGM)
  • Usage Type: Designed for Deep Cycle Usage
  • Construction: Valve Regulated, Spill Proof
  • Terminal Type: Nut & Bolt
  • Certifications: U.L. Recognized and CE Certified
  • Condition: Brand New, Factory Fresh
  • Warranty: 1 Year
  • Performance: Performance Guaranteed

Benefits

These replacement Invacare M61 batteries combine AGM technology and a valve-regulated construction to deliver a rugged, spill-proof power solution ideal for mobility devices. The deep-cycle design supports consistent discharge and recharge cycles, giving you a long-lasting battery that maintains capacity over time. As a high-performance battery option, it offers an excellent power-to-volume ratio for outstanding energy density — translating to longer run times for wheelchairs and power chairs.

Durability is built in: the sealed AGM design resists vibration and minimizes maintenance, while UL and CE recognition provide confidence in safety and manufacturing quality. Because they are factory fresh and performance guaranteed, these units are an excellent choice when you need dependable backup power. Typical applications include electric wheelchairs, power chairs, mobility chairs, and mobility scooters — and they can also serve in some UPS and emergency power scenarios where a long-lasting battery is required.

Installation is straightforward when replacing existing batteries: you should use all existing cables and hardware from your original setup to connect the new units. For additional assistance, customer service is available at or by e-mail.

Ready to restore mobility with a reliable, high-performance battery? Order your replacement Invacare M61 SP12-35 NB batteries today for a dependable, long-lasting battery solution and fast shipping.


Payment & Security

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