how can i fix mt makita battery?

I know this is an old thread, but I have a makita 18v battery, I used it to jump my car.. Yeah I know, 12v vs 18v, this worked 2 times before, barely drained the makita battery.. But this last time when I put it back I on the charger it flashes red and green... The battery still has a charge as it powers my drill and saw fine..

Anyway to tell the charger to charge the battery?

Brandon
June 2014

Do not try the suggestion that Javier recommends. I had 3 batteries that would take a charge and hold it that had the internal chip tripped so they wouldn't charge with the Makita charger. I tried the solution of opening the case and jumping to the bad battery, starting the charger and charging both in parallel. Afterwards both batteries did not work. They went from 17-20 volts down to under 10 and now won't seem to take a charge from the other charger I use.

jcssj
March 2013

Do not try the suggestion that Javier recommends. I had 3 batteries that would take a charge and hold it that had the internal chip tripped so they wouldn't charge with the Makita charger. I tried the solution of opening the case and jumping to the bad battery, starting the charger and charging both in parallel. Afterwards both batteries did not work. They went from 17-20 volts down to under 10 and now won't seem to take a charge from the other charger I use.

jcssj
March 2013

There's a good chance it's OK, but the safety program in the battery says it's not. This is very common. If it has had little use but went dead, probably the battery is still good but the safety program locks the battery, so it can't charge in Makita charger. Try to charge it on the Tenergy TB6-B charger and it may come back to life.

Toolmon
October 2011

You can't fix it.
Do not overheat battery when you use it ! If you battery is hot, whait, do not put it in to the charger !

Andy
October 2010

after fixing the battery you can charge it by oppening the charger and take out the positive and negative. plug them to the fixed battery, put a good battery on the charger and it will start charging both. it will have to be positive to positive and negative to negative if you ever mixt them or short them both batterys will break and the charger too.

javier
July 2010

how do I repair(open) my makita Ni-MH 14.4v 2.6Ah battery. i got 20 ones not holding charge.

richiewelsh
June 2010

how bad is the battery when the charger beeps and blinks green then red

daniel
March 2010

my 18v 3.0ah lithium-1on blinks red and green how can i fix it to get charge to batteries

daniel
March 2010

after reparing battery, for charging use 20v 200mA charger so you don't blow up battery pack...

Shults
January 2010

Hi Gaz,
you can repair a Makita LXT battery but it's probably not worth it. The Makita intelligent charger is intelligent in that it knows how to make more money for Makita. If you do repair the battery you won't be able to recharge it in the Makita charger, you need something like a universal laptop power supply and a timer so that the don't cook the battery. How I did it: get an appropriate screwdriver (T9 security I think, Maplins sell the correct one), open the battery, there are 10 cells wired in pairs, check the voltages with a multimeter, 3.6 volts is about right, if there is a low reading or zero, replace the cell(s) with the secondhand ones that you'll have to buy off of ebay unless you've got two broken batteries like lucky old me. Try to keep the soldered joints as flat as possible as you've got to get the whole lot back into the plastic casing.
Good luck

Steve Makita Hater
May 2009