How to Troubleshoot Cordless Power Tool Battery Chargers

Battery chargers reduce 110 volts to the voltage necessary to charge your power tool, usually between 9 and 24 volts. A Makita BL1830 battery charger contains separate internal wire windings, but no moving parts. It's simply the electricity flowing through the windings that causes resistance and reduces the voltage. Battery chargers don't contain any internal user-serviceable parts and they rarely go wrong. If you find your Makita 9134 battery charger doesn't charge your cordless power tool, try troubleshooting the fuses; they are likely to be the cause of the problem.

1Plug in your cordless power tool Makita BH9033 battery charger to the electricity supply. See if the power light is on. If it is, you know electricity is getting to the charger, so it's not the fuse in the plug that is the problem. It's likely to be the fuse in the charger. If the power light isn't on, remove the plug from the socket.
2Remove the cover from the plug so you can access the fuse. Use a screwdriver to remove the screw holding the cover in place, then lift off the cover.
3 Pry out the fuse from the fuse holder using your fingers or a small screwdriver. Put a replacement fuse into the fuse holder. The replacement fuse must be the same amperes as the one you just removed.
4Replace the cover on the plug. Insert the screw into the screw hole and tighten with a screwdriver.
5 Insert the plug into the socket. See if the power light is on. If it is, then it was the fuse -- and your charger works. If the light isn't on, it's likely to be a fault in the internal windings. Get it checked professionally, or purchase a replacement.
6 Remove the plug from the socket. Inspect the fuse on the Makita BH1433 cordless power tool battery charger. Your power light was on, so you know it's getting electricity.
7Locate the fuse cover; it's usually on the base of the charger. Either unclip the fuse cover by inserting a small screwdriver under the lip and prying it off. If it has a screw, remove it with a screwdriver then lift off the cover.
8Remove the fuse from the fuse holder. Lift out the fuse with your fingers or use a screwdriver. Replace the fuse, using one that has the same rating. Replace the fuse cover by either pushing it into place or replacing the screw and tightening it with a screwdriver.
9Insert the plug into the socket. Connect your cordless power tool to the charger. See if the charging light illuminates. If it does, your charger is charging the power tool. Let it charge until it's full. If the charging light doesn't illuminate, you have a fault with the internal windings. You need to get it checked out, or get a replacement charger.