Scientists are discovering how batteries charge by watching the behavior of individual molecules as they absorb charges.

It has long been assumed that batteries charge at a uniform rate, but Stanford's Institute for Materials and Energy Sciences at the US Department of Energy's (DOE's) SLAC Accelerator Laboratory says this isn't the case.

They have begun looking at the nano-scale and found that they charge and discharge very differently.

Regardless of the charging rate, only a small percentage of the nano`particles in the batteries tested actually absorbed ions. Those ions would then pass their charge onto others, and absorb new ions.

Discharge rate was dependent on speed of discharge. The researchers find that when a battery is being discharged quickly, the process is relatively uniform, but under a slow discharge, only a few nano particles are discharging at any given time.

The hope is that by getting a better understanding of what's going on at the nano-scale, the SLAC research can help design better batteries.