Why Won't My Black & Decker Electric Trimmer Hold a Charge?

You must get this battery back up and running to get the engine started again.

Corroded Terminals

Most often the problem lies in the positive and negative terminals on the battery. These terminals work in conjunction to supply the energy needed to charge your battery. Over time, a small amount of battery acid may leak out onto the terminals, developing a thin layer of corrosion, which looks like blue rust. If this corrosion prevents the current from circulating from the charger to the battery, the battery can't get the charge. Clean the positive and negative terminals on the battery and charger with a sponge and mild cleaning agent like dish detergent to prevent corrosive buildup from stopping your charge.

Problems in the Charging Circuit

Your problem may lie though in the charging circuit on the battery charger. Loose, damaged or poorly connected wires within the charging circuit will create a significant loss of battery power. Outlet plugs and wires can also fray or get damaged from pulling it out by the cord and not the plug. Look for any damaged or loose wires around the charger. Another electric circuit exists inside the Black & Decker itself. If the wires or connections aren’t established correctly, even if your battery is charged, it won’t deliver that charge to the engine. Leave all electrical repairs to a qualified service mechanic.

Checking With a Voltmeter

You can check the operation of your battery with a voltmeter. This machine will tell you if the battery is producing usable electricity, and, if so, how much. The voltmeter hooks up to the positive and negative terminals of the battery, so you can figure out if the problem lies in the battery or not. If the battery’s reading is more than 6 volts, it’s working just fine.

Bad Battery

The battery uses up a little bit of its acid every time it gets charged. So after repeated chargings through the years, it may just be time for a new battery. If the voltmeter shows no volts produced, you definitely need to buy a new battery. If the voltmeter is showing volts, but the battery is draining too quickly, this is also a sign that it’s time for a new battery as the acid is wearing low inside. Also beware of overcharging your battery, which can use up the acid like repeated charging.