The batteries have demonstrated charging capacities of between 25 and 33 mAh g−1 or 38−50 mAh g−1 per weight of the active material, can be charged with currents as high as 600 mA cm−2, and lose a mere six percent of their charging capacity after 100 charge/drain cycles. To quote from the link below, "In layman’s terms, these batteries are extremely light and can be charged in “11.3 seconds at 320 mA”.
The algae batteries have yet to be incorporated into a robust packaging which is another challenge for the team who have now made a battery that can take 1000 charges.
The batteries are of interest particularly because they should be cheap and amenable to mass production. However, as a consequence of their “low storage capabilities” they are unlikely to find application in e.g. MP3 players or laptops and certainly not in electric cars.
Prof. Maria Strømme said:
With the technique fully developed, I believe that we may see applications that we cannot really dream of today. Try to imagine what you can create when a battery can be integrated into wall papers, clothes, the packages of your medicines, etc.
At any rate it is interesting, as a cyborg device which does not require metals to make its essential working component, and even the polypyrrole conductor could be produced from biomass. That noted, I don't honestly see this as a saviour technology to obviate the energy crunch, but nor is it promised to be. Probably the most impacting use of algae in this respect is to make synthetic fuels, to replace increasingly scarce and costly oil and natural gas.
"Green rechargable batteries are made from algae." http://green.blorge.com/2009/09/green-rechargeable-batteries-are-made-from-algae/