Makita 40V battery does not want to charge. I faced this small problem when my Makita XGT 40V battery simply refused to charge. I put it on the charger, but it did not give any response like the normal charging process.
Instead of immediately dump it and buy a new pme, I thought that probably there is a way to revive it. In the end I found a simple trick that works very well.
I did a jumpstart with another working Makita 40V battery, to give voltage to the bad one so that it can directly receive the power from the healthy battery pack. For that, you need a second battery from the same 40V series that still works. Because the terminals sit inside the battery housing, you must check carefully for the markings.
How to Jump-Start a Makita 40V XGT Battery to Restore Charging
I put both batteries on the table with their terminals upward. Here were two: one dying that did not want to charge, and the other fully charged 2.5Ah unit that always well serves. The idea is to use jumper-wires to connect same terminals between them.
The job started with the positive terminal. I took a short cable with clips on both ends and attached one to the plus of the good battery. The second end I connect it to the plus terminal of the dead one.
For the negative terminal, I did the same with another wire.
When both cable connected between the batteries, the dead unit receives voltage from the healthy one. From the video above clearly show that the connection must last around 15 seconds. Watch the cables carefully.
No problem appeared, no smoke, no heat was felt. The voltage transfer went smooth, without any trouble. This short jump gives the dead battery little voltage, to restart its protective circuit and allow charging again.
When the time ended, I removed both cables and put the good battery aside.
I took the dead unit and placed it in my Makita DC40RC charger. This device works with the XGT 40V line and has charging indicator lights on the front. I inserted the battery in the charging slot and waited, what will happen.
Only after some seconds, the light blinking blue again.
The blinking blue light of the charger shows that everything is fine. At Makita XGT chargers, this is the usual sign of charging. Blue blinking means that the battery charges normally and the charger spots it.
Before the jump, this unit did not give any signal on the charger. Now it charges like new. Worth the effort.
I left the battery there to fully charge it. A little voltage push is everything what the safety system of the battery needs to wake up, so that is why such tricks help.
