Modifications

{{bloc-etroit|text=Les caractéristiques sont ces valeurs que l'on peut mesurer et qui nous apprennent des choses utiles sur ces piles que nous avons justement en main.

{{bloc-etroit|text=Les caractéristiques sont ces valeurs que l'on peut mesurer et qui nous apprennent des choses utiles sur ces piles que nous avons justement en main.

There are a few different ways to 'measure' batteries, here are the ones I will be comparing

Il y a différents façons de "mesurer" des piles. En voici quelque-unes que nous allons comparer

* '''Size'''<br />This is pretty straight forward, how big are the batteries? Lead acid batteries don't get much smaller than C-cell batteries. Coin cells don't get much larger than a quarter. There are also standard sizes, such as AA and 9V which may be desirable.

* '''La taille'''<br />Cela semble couler de source "La grandeur de la pile"? Les piles acide/plomb sont généralement plus grandes que des piles LR14 ([http://fr.wikipedia.org/wiki/Format_des_piles_et_accumulateurs_%C3%A9lectriques taille C]). Les piles boutons sont généralement plus petites qu'une pièce de 20 cents d'Euro cents. Il existe aussi des tailles standards comme AA et 9V qui seraient plus convenable suivant les situations.

* '''Weight and power density'''<br />This is a performance issue: higher quality (and more expensive) batteries will have a higher power density. If weight is an important part of your project, you will want to go with a lighter, high-density battery. Often this is expressed in Watts-hours per Kilogram.

* '''Poid et densité de puissance'''<br /> qui sont des caractéristiques relatives aux performances. Les piles de plus grande qualité (et aussi plus chère) disposerons d'une densité de puissance plus élevée. '''*** TRADUCTION ***''' If weight is an important part of your project, you will want to go with a lighter, high-density battery. Often this is expressed in Watts-hours per Kilogram.

* '''Price'''<br />Price is pretty much proportional to power-density (you pay more for higher density) and proportional to power capacity (you pay more for more capacity). The more power you want in a smaller, lighter package the more you will have to pay.

* '''Price'''<br />Price is pretty much proportional to power-density (you pay more for higher density) and proportional to power capacity (you pay more for more capacity). The more power you want in a smaller, lighter package the more you will have to pay.

* '''Voltage'''<br />The voltage of a battery cell is determined by the chemistry used inside. For example, all Alkaline cells are 1.5V, all lead-acid's are 2V, and lithiums are 3V. Batteries can be made of multiple cells, so for example, you'll rarely see a 2V lead-acid battery. Usually they are connected together inside to make a 6V, 12V or 24V battery. Likewise, most electronics use multiple alkalines to generate the voltage they need to run.<br />'''Don't forget that voltage is a 'nominal' measurement''', a "1.5V" AA battery actually starts out at 1.6V and then quickly drops down to 1.5 and then slowly drifts down to 1.0V at which point the battery is considered 'dead'.

* '''Voltage'''<br />The voltage of a battery cell is determined by the chemistry used inside. For example, all Alkaline cells are 1.5V, all lead-acid's are 2V, and lithiums are 3V. Batteries can be made of multiple cells, so for example, you'll rarely see a 2V lead-acid battery. Usually they are connected together inside to make a 6V, 12V or 24V battery. Likewise, most electronics use multiple alkalines to generate the voltage they need to run.<br />'''Don't forget that voltage is a 'nominal' measurement''', a "1.5V" AA battery actually starts out at 1.6V and then quickly drops down to 1.5 and then slowly drifts down to 1.0V at which point the battery is considered 'dead'.