no need to buy a duo charger on the much better icharger you can charge 2 batteries at once as long as there starting voltage is near the same.. go more now you will be happier in the end..a 180 watt total charger is still gonna be a long charge time till you run..I bought a Gt 1200 for 99 $ a few months ago. rev might still have some for cheap ull just need a power supply