- #1
Biycchu
- 8
- 0
Please help me. How many times I can charge my 5000mah mobile from 12 volt 7ah battery. I will use dc mobile charger.
How many times I can charge my 5000mah mobile from 12 volt 7ah battery?
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SUMMARY
The discussion centers on charging a 5000mAh mobile phone using a 12V 7Ah battery with a DC mobile charger. The most efficient chargers utilize a DC-DC converter to step down the voltage from 12V to 5V. Given the phone's 5Ah capacity at 5V and the external battery's 7Ah capacity at 12V, users can expect approximately 2-3 full recharges, accounting for energy losses. The total energy available from the 12V 7Ah battery is about 85Wh, allowing for an ideal scenario of up to 4.5 charges, though real-world factors will reduce this number.
PREREQUISITES- Understanding of DC-DC converters
- Knowledge of battery capacities and energy calculations
- Familiarity with mobile phone charging specifications
- Basic electrical concepts related to voltage and current
- Research the efficiency of various DC-DC converters for mobile charging
- Learn about energy loss factors in battery charging systems
- Explore specifications of different mobile phone batteries, particularly Li-ion types
- Investigate the performance of 12V sealed lead-acid batteries for mobile charging
This discussion is beneficial for electronics enthusiasts, mobile device users, and anyone interested in optimizing battery charging solutions using external power sources.
- #2
berkeman
Admin
- 69,346
- 24,678
Welcome to the PF. 
It depends on the charger. The most efficient ones will use a DC-DC converter to convert the 12V input to the 5V output for your phone's USB charger input port. Still, your phone has a 5Ah capacity at 5V, and your external battery has 7Ah capacity at 12V? If so, you will only get 2-3 recharges out of that external battery, most likely. What model is your phone, and which external battery are you wanting to use?
It depends on the charger. The most efficient ones will use a DC-DC converter to convert the 12V input to the 5V output for your phone's USB charger input port. Still, your phone has a 5Ah capacity at 5V, and your external battery has 7Ah capacity at 12V? If so, you will only get 2-3 recharges out of that external battery, most likely. What model is your phone, and which external battery are you wanting to use?
- #3
- 11,326
- 8,754
It also depends on the phone. I had a spare battery for a Samsung Galaxy S5. It was rated at 5.6 AH
- #4
Biycchu
- 8
- 0
my mobile is asus zenfone max pro m2. I will buy 7ah smf battery from amazon.
- #5
essenmein
- 657
- 294
5Ahr phone bat is probably Li-ion single cell, therefore 3.7V. So your phone needs about 18Whrs (5Ahrx3.7V) to charge from 0% charge to 100% charge.
A 12V 7Ahr battery contains about 85Whrs of energy so assuming no losses you could completely charge your phone about 4.5 times from that battery. Now there will be some losses in both batteries and in the charger itself which will reduce the number of full charges.
A 12V 7Ahr battery contains about 85Whrs of energy so assuming no losses you could completely charge your phone about 4.5 times from that battery. Now there will be some losses in both batteries and in the charger itself which will reduce the number of full charges.