The purpose of this site is to help with the design of a custom battery pack. This could be a battery pack for an all electric vehicle, a hybrid electric vehicle, or an off grid power supply -- such as a solar, wind, hydro or UPS power supply. An existing battery pack can also be evaluated.

The first part of this site is the Battery List. The Battery List is used to compare and select a specific battery for the pack. All the batteries that can be applied to the Pack Calculator appear in this list, which can be sorted on different calculated values to help determine the best battery for the application and budget.

The most ideal batteries, for any of the conditions, will be sorted to the top of the list. The sort conditions appear in a popup menu at the top right of the Battery List window and are as follows...

• watt-hours / dollar - the amount of energy storage compared to the battery cost.
• watt-hours / pound - the amount of energy storage compared to the weight (mass) of the battery.
• watt-hours / cubic-inch - the amount of energy storage compared to the volume (dimentional size) of the battery.
• cycle life - number of times the battery can be charged and discharged.
• watts (max) / pound - maximum power output compared to the weight (mass) of the battery.
• lifetime cost - total energy the battery will deliver over its lifetime compared to its cost.

Using the Battery List, locate and choose a desireable battery for the prospective battery pack. To choose a battery from the list, simply click on its image. A new page will appear displaying more details for the chosen battery and the Pack Calculator controls will appear below. The Pack Calculator controls are as follows...

• Series batteries - the number of batteries connected in series. As you add more batteries, the nominal voltage of the pack will increase.
• Parallel batteries - the number of batteries connected in parallel. More batteries in parallel will increate the amp-hour and maximum current rating of the pack.
• Cost - if a more accurate battery cost is available it can be entered here.
• Watt-hours per mile - this value helps to determine the range and life of the battery pack. Things get a little sloppy here -- keep this number a good bit higher than reality since the 20 hr rate is being used for the calculations. Typically, an electric vehicle will stress the battery pack much harder than the 20 hr rate, so the calculated total energy of the pack is actually quite optimistic and unrealistic. Sorry about this one.
• Optional pack title - This page can be printed and linked to, so a custom title can be entered to appear at the top of the page.
• Metric - check this box to have all values expressed in metric.

Once the desired values have been entered, click the 'Calculate' button and the pack specifications will appear. Each time a change is made to one of the values, click the 'Calculate' button again to update the displayed pack specifications. To start over with a different battery, click the Battery List link at the bottom of the page.

Below the Pack Calculator controls is a long URL in gray text, this is a link to the final calculated battery pack which can be bookmarked, emailed, or placed on a web page.

If you have any questions or comments about this page, please feel free to send me an email.