mAh rating on batteries

[David Rees]

A total newbie question, but something I'd like to know nonetheless.

You can buy AA batteries with a rating of 2300mAh (if not higher), as you
know, AA batteries are quite diminutive in size.

Compare with my laptop's batteries, almost brick-like in comparison, these
are rated for 4700mAh Lithium-Ion

So how can an AA battery, but a fraction of the volume of my laptop's
batteries, have half the capacity?

Or am I missing something?

Thanks

 

[scada]

A total newbie question, but something I'd like to know nonetheless.

You can buy AA batteries with a rating of 2300mAh (if not higher), as you
know, AA batteries are quite diminutive in size.

Compare with my laptop's batteries, almost brick-like in comparison, these
are rated for 4700mAh Lithium-Ion

So how can an AA battery, but a fraction of the volume of my laptop's
batteries, have half the capacity?

Or am I missing something?

Thanks

You need to factor in the voltage, and look at the total power in Watt
hours.

AA =1.5V * 2.3A = 3.45 Watt Hours

Laptop Battery = 12V (see rating) * 4.7A = 56.4 Watt Hours

 

[Peter Bennett]

A total newbie question, but something I'd like to know nonetheless.

You can buy AA batteries with a rating of 2300mAh (if not higher), as you
know, AA batteries are quite diminutive in size.

Compare with my laptop's batteries, almost brick-like in comparison, these
are rated for 4700mAh Lithium-Ion

So how can an AA battery, but a fraction of the volume of my laptop's
batteries, have half the capacity?

Or am I missing something?

Thanks

The AA battery is a single 1.5 volt cell. Your laptop battery may be
14.8 volts, so it can hold about 20 times the energy of the AA cell.


--
Peter Bennett, VE7CEI Vancouver BC, Canada
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Charles Schuler]

A total newbie question, but something I'd like to know nonetheless.

You can buy AA batteries with a rating of 2300mAh (if not higher), as you
know, AA batteries are quite diminutive in size.

Compare with my laptop's batteries, almost brick-like in comparison, these
are rated for 4700mAh Lithium-Ion

So how can an AA battery, but a fraction of the volume of my laptop's
batteries, have half the capacity?

Or am I missing something?

Yes, you are missing the electrochemistry differences of various storage
devices. They all have their place and they all are different.

 

[[email protected]]

A total newbie question, but something I'd like to know nonetheless.

You can buy AA batteries with a rating of 2300mAh (if not higher), as you
know, AA batteries are quite diminutive in size.

Compare with my laptop's batteries, almost brick-like in comparison, these
are rated for 4700mAh Lithium-Ion

So how can an AA battery, but a fraction of the volume of my laptop's
batteries, have half the capacity?

Or am I missing something?

Thanks

As a general rule rechargeable batteries have a lower capacity for a
given size.