MAKITA LXT BATTERY CHARGER

charging steady red then flashing red overheating and green red flashing replace battery.

Alternate Red and Green flashing means bad battery. Buy a new one, or take it to a Makita Service center for replacement if it's under warranty.

Normally the yellow light indicates hot battery, but it could also mean dirty battery contacts so the heat sensor can't be read, or that the fan is clogged with dust and unable to cool the battery. The manual says let the battery cool and try again. If the yellow still flashes, it's contacts or the fan.

Read the manual online at:
http://www.makita.ca/data/upload/accessorypbim/417_im_english.pdf

Your battery is shot. $75 - $100 for a new one.

This isn't true because I have a second charger and it works fine

If both lights are flashing it means the battery is defective so it won't charge it. By defective it could mean the battery is just worn out or there may be a short in the battery. If the battery is under warranty you can get it replaced at a Makita Service Center, if not you have to buy a new battery.

on my charger (DC18SC) alternating red and green dual flashes mean a defective battery.
http://ubermanuals.com/product/makita-dc18sc-8866 also same for the DC24SA

unplug charger to let it reset. plug back in and then try again, if it still flashes red/green that would indicate a battery failure. check for warranty replacement.

If the charge count on the batteries is under 300, Makita will replace them. Makita has a known defect in this battery that causes the battery to shut down before it is dead. So as of now they are exchanging ones with low use.

If they are truly defective and makita won't replace, you have to open them, find the dead cell or blown fuse, and replace. Search youtube makita battery for a video on repairing this battery. But once the red and green lights on the charger flash, the the battery can't be charged on a Makita charger -- it's been locked. So use a third party charger.

Yep, not the batteries, mine is doing the same thing but my second charger works fine with the same batteries