Apple iPhone 8 Compatible Battery 3.82V 1820mAh 616-00357
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Apple iPhone 8 Compatible Battery 3.82V 1820mAh 616-00357 - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
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
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
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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Apple iPhone 8 Compatible Battery 3.82V 1820mAh 616-00357 - is backordered and will ship as soon as it is back in stock.
Voltage
3.82V
Amp
1820mAh
Apple iPhone 8 — 3.82V Li-Polymer Replacement Battery (616-00357)
This is a 3.82V, 1820mAh Li-Polymer cell for the Apple iPhone 8. It fits models A1863, MQ7H2ZP/A, MQ6K2LL/A and other iPhone 8 variants sharing OEM part numbers 616-00357 and 616-00358. Capacity matches the original Apple specification at 6.95Wh.
- iPhone 8 model compatibility: All iPhone 8 variants listed share the same PCB layout, connector pinout, and BMS handshake protocol. The fuel gauge IC communicates over a single-wire authentication line — this cell carries the correct authentication data to pass that handshake without triggering a service warning in iOS Settings.
- Bench tested on actual hardware: We ran this cell on an iPhone 8 main board, monitoring charge IC behaviour through a full cycle. The BMS accepted charge current without fault flags, and the coulomb counter tracked state-of-charge correctly from 100% down to the low-voltage cutoff threshold.
- Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-to-charge cycle at standard 5W. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated counter — preventing erratic percentage readings from the first day.
Sudden shutdown at 20–30% on a freshly installed iPhone 8 cell
The iPhone 8 modem and display together can pull over 2A during peak load. A new cell with an uncalibrated fuel gauge IC may have its voltage floor set to the old cell's discharge curve. When load spikes, the cell voltage dips past the BMS cutoff threshold even though the displayed percentage reads mid-range. The phone shuts down not because charge is gone, but because the BMS trips on a momentary voltage sag the counter didn't anticipate. One full discharge-charge cycle at standard current recalibrates the coulomb counter and eliminates this behaviour.
iOS battery percentage jumping erratically after replacement
Erratic percentage jumps — five to ten points in seconds — happen when the fuel gauge IC is still using the discharge curve stored for the original cell. The coulomb counter loses accuracy as the new cell's impedance profile diverges from that stored curve. This is not a faulty cell; it is a calibration state. Perform one uninterrupted discharge down to automatic shutdown, then charge to 100% without interruption — after that cycle, percentage reporting stabilises.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Apple
- Manufacturer: CS
- Series: X-Longer
- Color: Black
- Product Type: Li-Polymer
- Battery Type: Li-Polymer
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My iPhone 8 shuts off randomly at around 25% after I put in the new battery — is the cell defective?
The cell is almost certainly not defective. This is a voltage-cliff shutdown: during a modem or screen load spike, the cell voltage dips below the BMS cutoff threshold even though the displayed percentage reads mid-range. The fuel gauge IC is still calibrated to the old cell's discharge curve, so its state-of-charge estimate is off. Run one full discharge to automatic shutdown followed by a complete charge to 100% at standard 5W — this recalibrates the coulomb counter and stops the shutdowns.
Fast charging stopped working after I replaced the battery on my iPhone 8 — it's only taking slow charge now.
On first cycle after a cell swap, the charge IC can default to standard 5W current until it completes an initial handshake with the new BMS. This is normal behaviour, not a fault. Let the phone complete one full charge at 5W before connecting a fast-charge adapter. If fast charging still doesn't engage after that cycle, check that the Lightning cable and adapter support USB-PD — the phone will not negotiate higher current with a non-compliant charger regardless of the battery.
The phone gets noticeably warm near the back during charging right after the replacement — should I be worried?
A new Li-Polymer cell has slightly higher internal impedance than a broken-in cell, so the charge IC dissipates more heat during the first few cycles as it pushes current into a cell it hasn't yet profiled. This warmth is normal and reduces after two to three charge cycles as impedance settles. If the phone becomes hot to the touch rather than warm, remove it from the charger and check that the replacement cell dimensions match the original — a cell seated against the battery connector at an angle increases contact resistance and heat. Confirmed fit dimensions for this cell are 92.70 × 38.52 × 3.50mm.
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