Battery Power Supply

Battery information

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How old batteries work in GSM relay?

The charger keeps battery operating even the battery is otherwise no use in normal gsm phones. If the charger refuses to charge the battery, then is time to replace it.

Can the charger be connected to the GSM phone all the time?

Yes, the Li-Ion chargers must regulate the upper voltage to 4.2V. If the battery needs charging it is done automatically.

How the battery woks in the cold weather?

I have left my GSM phone many times into car when the temperature was -28 .. -30C. The phone has worked normally.
If you want to be sure, connect a small PTC resistor directly to battery ( 12V or 24V). The PTC-resistor adjusts itself to +60-70C. If the phone are insulated, the phone works well in the cold weather. The power used is about 2W.
PTC model B59890

Replacing the the battery with 12V power supply a

The 4.2V lithium batteries can be replaled with 12V power supply
During the phone call Nokia phones use 250mA, but at start they use full 2W RF-power for firs second.
If the power supply is not good enough, the phone resets.


If battery back is needed , please use UPS or normal lead battery ( 3W 12V)

9Ah 12V battery

Optoisolator PC817

General UPS device
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