Makita BR1815 li-ion batteries won't charge

You batteries may be dead. Any battery can only take so much charging before they quit on you. If your charger shows that it is charging and it still has not charged overnight, it is the battery. You can search on YouTube how to "recharge" Makita batteries when this happens. The Makita battery charge has built in diagnostics that will tell you if a battery is bad or not, but will not tell you if the battery no longer has the ability to charge.

ITS LOADING if green light RAPID BLINKING SLOW BLINKING YOU HAVE LI-ION BATTERIES THE BEST IS TO HAVE THEM ALWAYS ON THE LOADER IF IN USE ; THERE IS NO MEMORY EFFECT OR TRAINING NECESSARY THAT WAS THE NICKEL CADMIUM PERIOD OF THE HEAVY BATTERIES , when a li-ion battery is too long without charging and using on time when the battery is below the dc level it should have it is possible that the loader will not accept the battery anymore, no problem take 2 short wires of a powercable and from a full loaded battery take the + connector and connect to the + with the problem battery and also the - to the - and wait for a moment 4 or 5 minutes that should be enough so the deep unload protection level is high enough loaded to accept the battery again on the loader MAKITA HITACHI MILWAUKEE DEWALT and much more brands its the most safe solution to get that dead battery working again. because not always is there a real problem but when too long inactivity 1 or 2 years on a li ion battery it is not dead or have only used one battery too long without changing it

Makita chargers are designed to check a battery before charging them. If both the red and green lights are flashing after you put a battery on the charger, it is reading a problem with the battery and will not charge it. It could be a bad cell, a problem with the circuit board, etc. but as long as it reads the problem it will not charge the 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

according to the schematic I saw yes you can and I think that you will be pleased with its performance, their operator manual even lists the weight of tool with this battery. Makita has a 1 year limited warranty on the Li-Ion battery that you might want to consider if you have the receipt.

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.

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.

does it have green blinking light when you plug it to mains w/o battery in it ?

Return to store for replacement.