**Battery energy and discharge rate**

**http://www.alternate-energy.net/calculateamp02.html**

**“battery amp hour calculator:**

**Enter battery voltage,
amp hours, and wattage of appliance**

**Will calculate run time**

**Ie**** 12 volt, 450 AH will run
100 watts for 45 hours**

**
200 watts for 22.5 hours**

**
400 watts for 11.25 hours**

**Simple uses P= IV
and def of amp hour**

**To what level of discharge does this bring the battery?**

Discharge
Rate

The storage capacity is expressed in amp hours at a certain discharge rate. The
discharge rate of a battery is the amount of time a battery is designed to
deliver its full capacity. For example, a 100 amp hour battery with a 20 hour
discharge rate is designed to deliver 5 amps. Every hour it will deliver 5 amp
hours and in 20 hours it will have delivered 100 amp hours (if it could be
completely drained). If the battery is discharged faster, its capacity will be
less and if it is discharged slower, its capacity will be greater. If this same
100 amp hour battery was discharged at 20 amps instead
of 5 amps its capacity would drop to only 60 amp hours! So, at a 5 hour
discharge rate, our 100-amp-hour battery becomes a 60 amp hour battery.

http://www.sierrasolar.com/articles_categories.php?category_id=36

**plot**** of discharge rate vs amp hour capacity; **

**calculator****: for theoretical AH,
actual AH for given peukert number and rate of
discharge in amps, time in hours to 100, 80 and 20 percent discharge. 20
percent gives longest life**

**this**** is the best calculator
yet**

**could**** use this calculator to
make a plot**

**http://www.gizmology.net/batteries.htm**