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LG MS770 Replacement Battery BL-44JH 3.7V 2400mAh

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From $27.99 USD $34.99
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Fits LG MS770, Motion 4G, P870, US730 and 45+ variants; replaces OEM part BL-44JH.
This 3.7V 2400mAh cell delivers the same charge capacity as the original, sustaining normal daily usage across calls, texts, and standby.
Connector slides straight into the battery slot with the locking tab oriented toward the phone chassis; no modification needed.
We bench-tested this pack against the MS770 fuel gauge IC — BMS accepted the charge profile without fault codes on first insertion.
On first use after installation, run one complete discharge-to-shutdown and full recharge cycle without fast charging to let the coulomb counter recalibrate against the new cell curve.
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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

2400mAh

LG MS770 / Motion 4G — 3.7V Li-ion Replacement Battery (BL-44JH)

This is a 3.7V, 2400mAh Li-ion replacement cell for the LG MS770 and Motion 4G smartphones, also covering the P870 and US730. It matches the original BL-44JH footprint and connector. Swap it when the original cell no longer carries the phone through a full day.

  • MS770 / Motion 4G platform fit: These models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. One cell covers the full group — no adapter or modification needed.
  • Bench tested on actual hardware: We ran this cell on the MS770 platform through charge initiation, BMS negotiation, and full discharge. The protection circuit tripped correctly at low-voltage cutoff, and charge acceptance at the standard 5V rail was confirmed without error flags.
  • Fuel gauge recalibration after install: On first use, disable fast charging and run one complete discharge-charge cycle before returning to normal use. The MS770's fuel gauge IC carries calibration data from the old cell — letting it map a full curve against the new cell's discharge profile prevents the percentage counter from drifting immediately after the swap.

Sudden shutdown at 20–30% on the MS770 after a cell swap

This is a voltage cliff issue, not a capacity defect. Under heavy modem or display load, the cell's terminal voltage drops faster than the fuel gauge predicts — the phone shuts down to protect the circuit before the reported percentage reaches zero. The fuel gauge IC is still calibrated to the old cell's discharge curve, so its percentage estimate diverges from actual cell voltage under load. One full discharge-charge cycle with no fast charging resets the coulomb counter and realigns the gauge to the new cell. After calibration, cutoffs above 15% typically stop.

Phone not powering on after the replacement battery sat in storage

Li-ion cells in storage self-discharge over time. If the cell dropped below 2.5V per cell, the BMS trips into lockout mode and blocks charge input entirely as a safety measure. Plug into a wall charger — not a PC USB port — and leave it connected for 15–20 minutes without pressing the power button. Most BMS circuits on this platform recover from lockout once the charge IC pushes a trickle current in, bringing cell voltage back above the 2.9V re-enable threshold before normal charging resumes.

Compatible Models

MS770 Motion 4G P870 US730 Escape 4G Splendor Venice Mach LS860 Optimus L5 II E450 P700 Optimus Select Optimus Zone 2 VS415 Splendor US730 Venice LG730 Optimus Fuel L34C Cayenne 4G LTE Mach 4G LTE Cayenne Optimus Zone 2 Optimus Zone II VS415 VS415PP LG-VS415PP TFLGL34CTM3PWP Optimus Dynamic 2 L39C NTLGL39C3PWP Optimus Logic L35g L35 L38C Motion4g US770 E451G Optimus L7 Optimus P700 Optimus P705 Optimus P705g Optimus P750 AS730 Wine Smart H410 H410 Avec Wine Smart H410 Wine Smart Jazz Wine Smart II

Replaces Part Numbers

BL-44JH EAC61839001 EAC61839006

Technical Specifications

Voltage3.7V
Amp Hours2400mAh
Capacity2400mAh
Rate8.88Wh
Net Weight61g /2.15 oz
Gross Weight86g /3.03 oz
Approximate Weight86g /3.03 oz
Dimension 64.85 x 43.26 x 10.50mm

Product Highlights

  • Brand: LG
  • Manufacturer: CS
  • Series: Extension
  • Color: Black
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My LG MS770 shows 25% battery and then just cuts off without warning — is the new cell faulty?

The cell is almost certainly not faulty. This is a voltage cliff: under modem or screen load, the cell's terminal voltage drops sharply, and the phone's protection circuit shuts down before the percentage counter catches up. The fuel gauge IC on the MS770 is still mapped to the old cell's discharge curve after a swap. Run one full discharge-charge cycle with fast charging disabled — this lets the coulomb counter recalibrate against the new cell, and unexpected cutoffs above 15% typically stop after that.

The battery percentage on my MS770 is jumping around erratically after I put in the replacement — 60% one minute, 45% the next.

This is the fuel gauge IC recalibrating. The MS770 stores charge curve data from the previous cell, and the new cell's discharge characteristics don't match that stored profile. The gauge reads raw voltage and converts it using the old curve, producing erratic jumps when the two curves diverge. Let the phone run through two complete discharge-charge cycles — fully to shutdown, then fully to 100% on a wall charger — and the percentage display will stabilise as the IC builds a new curve map.

I installed the BL-44JH replacement and the MS770 feels warm near the battery compartment while charging — is that normal?

Mild warmth on the first one or two charge cycles is normal for a new high-impedance cell. A fresh Li-ion cell has slightly higher internal resistance than a broken-in cell, so the charge IC dissipates a little more energy as heat during constant-current phase. If the phone becomes hot to the touch or charging stops prematurely, remove it from any case to improve airflow and charge on a flat surface. Warmth should reduce noticeably after the cell completes its first three full cycles.

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