You do not need a special back cover to use this battery
This package is specifically designed for the cellphones we list here, if your cellphone is not in the list , then it's not for you.
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100% Brand New.
1)AC/USB Desktop Battery Charger :
* Quick charge with automatic constant current control prevents battery from over charging, short circuit, and electronic shock.
* Charge your cell phone battery without the phone.
* Also work with OEM (original) battery.
* LED charging light indicator. Turn red in charging, turn blue when done.
* Input: AC 100-240V 50/60Hz 150mAh.
* Output: DC 4.2V 350mAh ± 50mA.
* USB Port Output: 5.2V 800mAh.
* Use this charger to charge the stock battery as well, swap one out when the other dies.
2)New 3400mAh Rechargeable Li_ion Battery:
* Brand: Unbranded/Generic .
* High quality Li-Ion battery.
* Battery Type: Lithium Ion.
* Battery Capacity: 3400mAh .
* Voltage: 3.8V.
* The best spare battery for your phone.
* Best Replacement for the original battery with comparable standby and talk time .
* Our battery is sent out with little or no power, so please charge it for about 6 - 12 hours before using.
* Keep an extra battery on hand for extend standby and talk times.
* Integrated microchip prevents overcharging and lengthens battery life.
* This Battery could also be charged in the phone directly thru the cell phone charger.

• * Package includes: New 3400mAh Rechargeable Li_ion Battery X 1
• * External Special Travel Dock USB/AC Charger X 1
• * Compatible with: Samsung Galaxy J3 SM-J320A( AT&T )
• * Accessory only, cell phone not included.
• * High Quality,100% Brand New.

* Package includes: New 3400mAh Rechargeable Li_ion Battery X 1SharpCost