Here is the compatible battery for sale which fits Makita's BDF451 driver drill kit: http://www.ebay.co.uk/itm/18V-3-5Ah-Battery-Makita-BL-1830-BHP452-18-V-BTW251-ML184-FlashLight-/370581531251?pt=UK_Home_Garden_PowerTools_SM&hash=item5648616a73
Help you to find the power tools replacement batteries with high quality and low price (ebay shop: googolpower): http://stores.ebay.co.uk/Googol-Power/Power-Tools-Batteries-/_i.html?_fsub=657839018&_sid=196708718&_trksid=p4634.c0.m322