Ive had two compact m18 milwaukee red lithium batteries fail on me after 4 months of use. I rarely used them considering i have more XC batteries.maybe 40 charges all together and they cut out and wouldnt charge. I called milwaukee they told to send them in with my own money and that it would take 2 months to get them back to me. When they recieved they called me and told that sawdust on the outside suggested abuse on the batteries and they denied me warranty service. My makita lithium ion batteries all made it to a 6 year mark after a ton of use and charging and two out of the 4 wont charge anymore a good run for the money tho but i have heard locally that any exposure to moisture will kill a makita battery but they say that milwaukee,bosch and other batteries arent affected by the moisture. Hows the battery life on your 18v metabo impact driver? my milwaukee one is starting to die out thinking about switching....