Hello, the ant protection board is a device used to protect electronic devices from overcurrent, overvoltage and overheating damage, it is not used to charge itself. So, the ant shield can't be used directly to charge. However, when you use a charger or power adapter to connect to the ant protection board, it can protect your device from excessive current or voltage damage.
1. Battery imbalance --------- One or more batteries reach the overcharge protection voltage of the protection board.
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2. The mos of the charging direction of the protection board is broken.
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3. The protection IC is broken.
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4. The device between IC command mos is broken.
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5, the NTC resistance of the protection board is bad or the resistance value is wrong -- leading to the IC that the battery is in a high temperature state ---- prohibit charging.
The single protection board can not be charged, you can directly find the positive and negative terminals of the lithium battery cell, and measure the voltage at both ends: if the nominal voltage is 3, 7V, then see how much the measured value is. If the cell voltage is measured. 3V while the protection board has no output