Comments by Gerard M.

  • Understanding battery capacity: Ah is not A

    Understanding battery capacity: Ah is not A

    - 9 January 2014

    Hi Jan

    Glad i came across this blog, you really seem to know your stuff!

    I would like your advice about some power banks I have recently purchased from china as i am currently in dispute over the specification with the supplier. The power banks i purchased state that they are 50Ah capacity. I do have some degree of electronical knowledge as i studied a-level technology and briefly studied electrical engineering several years back. As you have mentioned in a previous point i was going on the basis that this would provide 1A for 50 hours and inversely would take 50hrs to charge at a rate of 1A. After some research and charge / discharge tests it seems the actually capacity would be about a 1/5th of this as it was fully charged in about 10hours. I have included two extracts (Sorry about the big post) from the supplier below and would hope you can make more sense than me of this as the english is terrible! What I would like to know is if i am misunderstanding the specification and the correct definition is actually 50Ah or is the supplier trying to con me?

    "Power bank real capacity is 12000mah. The really full charge 50000mah battery is more than 5KG weight .It is very dangerous and inconvenient. So the market is almost no more than 13000mah, let alone 50000mah. Special Note: our solar power bank built-in electric current and voltage protection of 50000mah, if your area voltage instability or excessive current input, our 50000mah play a very large role in the protection, safeguard the security of each buyer, which is also the advantage of our products and new technologies, so this product is defined as solar power bank 50000mah, you understand it?

    "Our electronic components and batteries imported technology from Japan, its quality is very good. 50000mAh mean explanation can carry 50000mAh energy, charge for 48 hours or even 72 hours can be achieved 50000mAh. Simultaneously protected and will not explode this is the EU's safety standards, but it is when the output current. impossible to achieve 50000mAh energy. scope of its output value to between 12000mAh 15000mAh. 12000mAh lowest output standard, you understand?"

    Thanks

    Gerard

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