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I've ordered 12 cell 7200mAh battery for my notebook HP HDX18t. When I received the battery it says 14.4V/7800mAh ( and not 7200mAh like it was stated).

1 - According to this site the number of cells in this battery is 7800mAh/2600mAh * 14.4v / 3.7v = 11.6 cells.

I installed BatteryCare program and this is what it shows

battery info

2 - According to this site the mAh of battery (converting from mWh) is 96768 / 14.4 = 6720mAh

My question is

a - Should I consider 11.6 that I got in (1) to 12 or 11 cells?

b - From (2) I didn't get neither 7800mAh nor 7200mAh but 6720. Does it means that the battery I got is not new or I should wait until I will recharge&charge it several times and after that it should increase the number in Total Capacity?

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closed as off topic by Leon Heller, Brian Carlton, clabacchio Mar 20 '13 at 9:18

Questions on Electrical Engineering Stack Exchange are expected to relate to electronics design within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here. If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ Sorry but consumer electronics like laptop batteries are not a good fit for this site, SuperUser is better for this kind of questions. \$\endgroup\$ – clabacchio Mar 20 '13 at 9:21
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  1. 7800 mAh = 2400 mAh * 3... you have exactly 12 cells, connected 3 in parallel (increasing current) and 4 in series (increasing voltage).

  2. The voltage doesn't stay constant during discharge, so you cannot just say 96768 / 14.4. Also, capacity will decrease as the battery ages. (But, your software is convinced this battery is very new; this will reflect the metadata stored in the control circuit, not the cells themselves).

    Because the total capacity you got is greater than the "design capacity", do not expect your battery to "break-in" or otherwise improve beyond what you see now.

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