Custom battery packs...give us a call.  We can help you design and then build your custom battery packs. 

We are battery pack experts. We have designed custom battery packs for many different applications

Why Battery Packs? Cells are like eggs. They come in fixed voltages and capacities. You can't get half an egg, and you can't get half a cell, at least in voltage. Capacities do vary, particularly with a supplier like Tenergy that has a great variety of cell sizes available, but voltages don't. A NiCd or NiMH cells are 1.2 volts nominal, lead acid is 2.0 volts nominal and the various lithium technologies are about 3.6 volts per cell. If you need more voltage you have to add them in series, if you need less voltage you need some kind of voltage regulator or DC/DC converter.

If you need more current you may need to put cells in parallel. If you need more capacity you may need to put cells in parallel.
Many times the physical configuration makes it more attractive to use many small cells rather than a few large cells.

Basic Battery Pack Configurations

There is basically 5 different configurations for cylindrical base cells, click here for the configurations, the Li-Polymer Packs has less combination