How To Fix A Makita Drill Makita Drill Battery

Remove the cover from the makita drill battery pack. It usually has six to eight small Phillips screws holding the cover in place so use a suitably sized Phillips screwdriver to remove the screws. Once removed you see the individual cells.
Get a voltmeter. Start at the top of the makita drill battery pack (Makita 193158-3 drill battery) as you need to get a system in place to test each cell. Put the sensor on the end of the red wire that's attached to the voltmeter onto the positive cell terminal. Put the senor on the end of the black wire that's attached to the voltmeter onto the negative cell terminal. The cell terminals are labeled "+" and "-."
Make a note of the type of cell you have removed from the power drill makita drill battery pack as you need to get replacements that are exactly the same. The type of cell is clearly marked down the side and is likely to read "NiCad," meaning nickel cadmium, or "NiMH," meaning nickel metal hydride.
Get replacement cells to replace the cells you've removed from the makita drill battery pack. They are widely available from electrical outlets. It's helpful to take along one of the cells so you can be certain of the getting the same type.
Makita batteries are used to power their range of cordless tools. The voltage output from each battery depends on the number of cells it contains and the voltage requirements of the power tool. Makita battery packs made from nickel cadmium (NiCad) or nickel metal hydride (NiMH) cells each produce 1.2 volts wired in series so, for example, a Makita 9.6 volt battery has eight cells. If you find your battery is dead, fix it rather than purchase a new one.
Remove the cover from the Makita battery pack. Most covers are held in place using small Phillips screws, so use a suitably-sized Phillips screwdriver. However, if you find your Makita battery is a sealed unit, its best not to force it open as you will damage the pack, and it could be dangerous. Get replacements this time, ensuring it has a removable cover.
Use a voltmeter to check the voltage from each cell. Good cells produce 1.2 volts: bad cells have lost their power. Attach the sensor on the end of the red wire from the voltmeter onto the positive terminal of a battery cell: Then attach the sensor on the end of the black wire onto the negative terminal of the same cell. The positive terminal is labeled "+" and the negative terminal "-."
Read the display on the voltmeter. If it says between 1.1 and 12 volts the cells is good. If it reads less than 1.1 volts, you need to replace it. Make a mark on the cell with a pen, so you know which ones are bad. Repeat the process on each cell. Label bad cells
Write down how the cells are placed into the battery casing and which cells are soldered together, taking particular note of the cell polarity. You will want to make sure that you maintain the correct polarity positions during reassembly.
Purchase new matching cells at a local electronics or hardware store. Only replace size C NiCad batteries with the same type of battery. The Makita battery pack should not be restored by mixing Nicad, lithium and NiMH batteries within the chain.