Welcome to our store. Your trusted source for batteries and power solutions. Learn more

For support or quotes: sales@batteryweb.com
WELCOME5
BatteryWeb

Harman/Kardon Onyx Studio 8 ICA077NA Replacement Battery 3.7V 3350mAh

Up to 19% off
New arrival
From $49.99 USD $61.99
Shipping calculated at checkout.
Fits Harman/Kardon Onyx Studio 8 with OEM part number ICA077NA.
3.7V 3350mAh lithium-ion cell delivers 12.4Wh to sustain full wireless playback on the Onyx platform.
Connector slides into the factory battery slot with positive terminal forward; locking tab seats flush against the housing.
We tested the ICA077NA BMS on bench charge cycles — initial acceptance at 5V/2A, ramp to full capacity without early cutoff or thermal drift.
On first insertion, if the Onyx powers on but audio cuts after 15 minutes, remove the battery, wait 30 seconds, and reseat — the speaker's fuel gauge needs a clean contact cycle to sync with the new cell's BMS handshake.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
WECARE5
Visa Mastercard American Express PayPal Apple Pay Google Pay Shop Pay Discover Klarna Afterpay Stripe
✦

Check that your old battery model number and device model to match our description. This makes sure they work together.

✦

We ship your order same day if you buy it before 4 PM EST.

Warranty

Let customers speak for us

from 11 reviews

Product is exactly as described and arrived quickly

Robert Jones
Rocket ES4-12 Compatible Replacement Battery

It took a bit longer than expected, likely due to the holiday season, but that was understandable. So far, the battery seems to be working well!

Linda M.
MGE UPS Systems Pulsar EX 1500RT Compatible Replacement Battery By Bright Way

Excellent substitute for the original, appearing to be the perfect replacement.

Alberto J.
APC SMART-UPS RT SURTA3000RMXL3U UPS High Performance Replacement Battery Set

It was what i was looking for. Support is fast

Jaswal
WAHEGURUG - RADHASWAMI

Fast service

Mark Casias
BatteryWeb

Perfect fit

Mark Casias
STX20L-BS Battery for Harley Softail FLS FLST 1991-2017 High Performance

Works Perfectly!!

Ben Benson
Invacare 220 Scooter High Performance Medical Replacement Battery Set

Send Your Battery Photo

Expert Technician Help

Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.

POST YOUR BATTERY IMAGE
Product & Solutions Expert

Product & Solutions Expert

✉ sales@batteryweb.com

🔹 10+ Years Battery Experience 🔹 Fast & Accurate Identification

Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

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.

Voltage

3.7V

Amp

3350mAh

Harman/Kardon Onyx Studio 8 — 3.7V Li-ion Replacement Battery (ICA077NA)

This is a 3.7V 3350mAh (12.4Wh) Li-ion replacement battery for the Harman/Kardon Onyx Studio 8 portable Bluetooth speaker. It fits directly in place of the original ICA077NA cell. Order this when the original pack no longer holds enough charge to support a full listening session.

  • Onyx Studio 8 fitment: The Onyx Studio 8 uses a single-cell Li-ion pack at 3.7V nominal. The connector pinout and BMS communication protocol on this replacement match the original so the speaker's charge indicator reports state-of-charge correctly after installation.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Onyx Studio 8 platform. The BMS accepted the pack without fault codes, and the fuel gauge calibrated correctly within the first full charge cycle.
  • Monthly discharge cycle for Onyx Studio 8 users: Speakers kept plugged in or topped off constantly never fully discharge the cell, which causes fuel gauge drift over time. Run the Onyx Studio 8 down below 20% at least once a month before recharging to keep the gauge accurate and slow capacity fade on the Li-ion cell.

Audio distorting before the battery indicator reaches empty on the Onyx Studio 8

As the cell discharges toward its lower cutoff, the amplifier inside the Onyx Studio 8 draws more current than the voltage rail can cleanly supply. This causes the output stage to clip, producing audible distortion even while the battery indicator still shows one or two bars. It is not a speaker driver fault — it is voltage sag under amplifier load. A fresh cell with lower internal resistance holds the rail closer to 3.6V longer, pushing the distortion threshold much closer to actual empty.

Onyx Studio 8 not responding to USB-C charge after sitting unused for months

A deeply discharged Li-ion cell can fall below the minimum voltage a USB-C Power Delivery charger will recognise — typically around 2.5V — and the handshake never completes. The speaker appears completely dead even with a known-good cable. Try a charger that supports 5V 0.5A trickle output, which bypasses PD negotiation and can bring the cell back above the 2.5V threshold. Once the indicator LED flickers, switch to your normal charger and allow a full charge before testing playback.

Compatible Models

Onyx Studio 8

Replaces Part Numbers

ICA077NA

Technical Specifications

Voltage3.7V
Amp Hours3350mAh
Capacity3350mAh
Rate12.4Wh
Net Weight54g /1.90 oz
Gross Weight79g /2.79 oz
Approximate Weight79g /2.79 oz
Dimension 71.00 x 20.00 x 20.00mm

Product Highlights

  • Brand: Harman/Kardon
  • Manufacturer: CS
  • Series: Standard
  • Color: Blue
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My Onyx Studio 8 shows a full charge but the audio cuts out after about an hour — is the battery failing?

Yes. This is classic fuel gauge drift caused by shallow cycling — the speaker gets topped off before the cell fully discharges, so the gauge loses track of true capacity over time. The cell still reads "full" but actual usable charge is a fraction of that. Install a new ICA077NA cell, then run two full discharge-and-recharge cycles so the gauge recalibrates against the new cell's actual capacity.

Bluetooth disconnects on the Onyx Studio 8 when I push the volume past about 70% — why does this happen on a new battery?

At high volume, the amplifier and Bluetooth radio draw current at the same time, creating a combined spike the cell has to supply instantly. If the cell's internal resistance is even slightly elevated — common on an aged original pack — the voltage rail sags enough to trigger the radio's undervoltage reset. A replacement cell with lower internal resistance keeps the rail above the radio's minimum operating voltage through those peaks. If drops persist after fitting the new cell, check that the battery connector is fully seated, as a partial connection adds resistance and recreates the same sag.

The Onyx Studio 8 gets noticeably warm on the side during long play sessions — is that the battery overheating?

The heat comes from two sources stacked in a small enclosure: the Class D amplifier generating heat under sustained load, and the Li-ion cell generating heat as it discharges. Neither alone is dangerous, but the fabric housing traps both. If the surface feels hot rather than warm, pause playback for ten minutes to let the amplifier cool — sustained heat above 45°C accelerates capacity fade on the Li-ion cell. Keep the speaker on a hard, flat surface during extended use so airflow under the unit is not blocked.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Related Products

Harman/Kardon Onyx Studio 8 Replacement Battery, 3.7V, 3350mAh, Li-ion 1

Engineered for Performance. Built to Last.

Check out our top-rated selection of reliable products built to last. We offer high-quality options that deliver consistent performance for all your needs.

Our Collections