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

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

BLU Studio 5.5S Compatible Battery 3.8V 2100mAh C786340235T

Up to 21% off
New arrival
From $24.99 USD $30.99
Shipping calculated at checkout.
Fits BLU Studio 5.5S, D630U, D630L smartphones; replaces OEM part C786340235T.
3.8V, 2100mAh lithium-polymer cell delivers full capacity for calls, messaging, and app use.
Connector slides into vertical slot with single locking tab; verify tab alignment before closing.
We ran full discharge cycles on bench; BMS accepted charge current cleanly, no fault codes.
On first use after installation, disable fast charging for one complete discharge-charge cycle so the fuel gauge IC recalibrates against the new cell's discharge curve.
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

3.8V

Amp

2100mAh

BLU Studio 5.5S / D630U / D630L — 3.8V Li-Polymer Replacement Battery (C786340235T)

This is a 3.8V, 2100mAh Li-Polymer battery for the BLU Studio 5.5S, D630U, and D630L smartphones. It replaces OEM part number C786340235T. The battery slots into the same footprint as the original — 78.00 x 63.45 x 4.00mm — and connects to the same charge IC and fuel gauge circuit.

  • Studio 5.5S, D630U, and D630L compatibility: These three model numbers share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The fuel gauge IC on all three reads the same cell chemistry signature, so the replacement communicates charge state correctly across all variants.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a D630U. The BMS accepted the new cell on the first charge cycle, protection thresholds triggered at expected voltage levels, and the fuel gauge began tracking state-of-charge within one full cycle.
  • First-cycle calibration on the Studio 5.5S: On first use after installation, disable fast charging and let the phone complete one full discharge-to-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes load into an uncalibrated cell.

Why the Studio 5.5S reports the wrong battery percentage after a cell swap

The fuel gauge IC on the D630-series board stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches actual cell behaviour, so the reported percentage drifts from true state-of-charge. The IC needs at least one complete discharge cycle — from full to auto-shutdown — followed by a full charge to re-anchor its coulomb counter. After that cycle, percentage readings stabilise and track the new cell accurately.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under modem or screen load — a voltage cliff the fuel gauge didn't predict because it was still calibrated to the old cell. The BMS trips the output before the displayed percentage reaches zero. It is not a faulty battery. Run one full discharge cycle without interrupting it, then charge to 100%. After recalibration, the fuel gauge tracks the cliff correctly and the premature shutdowns stop. Confirm the cell is holding above 3.5V under load after that cycle.

Compatible Models

Studio 5.5S D630U D630L

Replaces Part Numbers

C786340235T

Technical Specifications

Voltage3.8V
Amp Hours2100mAh
Capacity2100mAh
Rate7.98Wh
Net Weight37g /1.31 oz
Gross Weight72g /2.54 oz
Approximate Weight72g /2.54 oz
Dimension 78.00 x 63.45 x 4.00mm

Product Highlights

  • Brand: BLU
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Li-Polymer
  • Battery Type: Li-Polymer
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

The BLU Studio 5.5S won't turn on after the replacement battery sat in a drawer for a few months — is the cell dead?

Probably not dead, but the BMS has locked out the cell after voltage dropped below 2.5V during storage. Plug the phone into a wall charger — not a computer USB port — and leave it for 30–40 minutes without pressing the power button. The charge IC needs to trickle current into the cell before the BMS will re-engage and allow normal startup. If the phone still won't respond, confirm the charger output is at least 5V 1A.

Fast charging stopped working on the Studio 5.5S after I put in the new battery — it only charges slowly now?

The proprietary charge protocol negotiation can fail on the first cycle when the BMS on a new cell presents higher impedance than the phone's charge IC expects. The IC drops back to standard 5V charging as a precaution. Complete one full slow charge to 100%, then disconnect and let the phone cool fully before plugging in again. On the second cycle the charge IC renegotiates the protocol correctly and fast charging resumes.

The battery percentage on my Studio 5.5S jumps around erratically — it reads 60%, then skips to 45% a few minutes later?

The fuel gauge IC is recalibrating its coulomb counter against the new cell's discharge curve, and the mismatch causes erratic percentage jumps. This is a software-side calibration issue, not a cell fault. Drain the phone fully until it shuts itself off, then charge it in one uninterrupted session to 100%. That single full cycle gives the fuel gauge enough data to lock onto the correct discharge curve and the percentage readings stabilise.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Bancontact
  • 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

BLU Studio 5.5S Replacement Battery, 3.8V, 2100mAh, Li-Polymer 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