Tips to repair your Makita 18v or 14.4v Li-Ion battery yourself
Update May 2019: Unfortunately, it appears that more and more batteries are more seriously defective than just the PCB. We have therefore stopped selling PCBs. We advise you to order a new replacement battery for your Makita machine.
Looking for a Makita 14.4v battery? Click here!
Looking for a Makita 18v battery? Click here!
Makita is known for its strong machines and its complete range of machines. These machines are of high quality and often only need to be replaced after years. Despite the quality of the Makita machines, the Li-ion batteries often appear to have a shorter lifespan than the machines. Often these defects are outside the warranty period and are not repaired by Makita. In most cases, the defect in your battery is caused by a broken motherboard in the battery. In this tutorial we explain in steps how you can replace this motherboard.
What problems can you solve with this repair?
The defects of the Makita Li-ion batteries can be divided into two 'causes'. The first cause is overheating of the battery and the second cause is the lack of current to supply voltage to the motherboard. This leads to an unbalanced voltage in the cells of the battery. If you have seen the red/green/white light on your charger flash three times, the motherboard is blocking the battery and charging is no longer possible. This manual discusses how to fix or repair the second defect. In order to fix this error, a new motherboard (PCB) must be placed on the battery.
Before you can start replacing the PCB, you should be aware that the cells in the battery may still contain residual voltage!
Disassembling the battery
In order to disassemble the PCB, the battery must be disassembled. By unscrewing the torx 10 screws, the housing of the Makita battery can be removed. The newer batteries have a rubber cap on these screws. This cap can be removed with a screwdriver.
Once the screws are removed the housing can be opened. When opening the spring under the push button can shoot away, be careful not to lose this spring. When opening the battery a lot of dust can be found in the battery. If this is the case, try not to charge the batteries in a dusty environment or charge the batteries while the charger is on a dusty surface in the future. The charger blows air through the battery to control the temperature, this air can suck in a lot of dust. This does not benefit the life of the battery!
Testing the cells in the battery
In order to determine with certainty that the PCB is defective, the cells must be measured individually. This can be done with a multimeter. The voltage of the cells must be measured between the six points indicated. Each cell, when charged, should give 4V, but this is often not achieved. The minimum voltage should be 3.2 volts. If one of the cells does not give any voltage or too low a voltage, it is possible to replace this cell. Replacing an individual cell is more expensive than just replacing the PCB. Our advice is to replace the battery and not to replace individual cells.
Disassembling PCB on Makita battery
In order to disassemble the PCB, some solder points need to be loosened.
- 2x red wire from PCB -> unsolder cell pack
- 1x black from PCB -> unsolder from cell pack
- Temperature sensor -> remove from cell pack
Mounting the new PCB
The new PCB should be done in the reverse order of disassembly. Be careful that the solder points are firm and not too fragile.
- Thin red wire is soldered to the side of the battery cells
- Thick red wire is soldered on top of the lip of the battery cells
- Black wire is also soldered to the lip of the battery cells
- Temperature sensor -> plug back between the cells for correct temperature measurement
Replacing the housing
When replacing the housing, follow the reverse steps of removing the battery.
Would you like to order a PCB for a Makita battery?
Unfortunately, it appears that more and more batteries are more seriously defective than just the PCB. We have therefore stopped selling PCBs. We advise you to order a new replacement battery for your Makita machine.
Looking for a Makita 14.4v battery? Click here!
Looking for a Makita 18v battery? Click here!
