Ryobi offers a wide range of cordless power tools with voltages ranging from 18 to 80 volts. Newer Ryobi cordless tool batteries using lithium-ion technology are generally considered safe but could still explode if not stored properly. Suggestions for storing Ryobi batteries include removing them from power tools, keeping them cool and dry, and ensuring they’re charged between 60% and 70% of their full capacity before storing. It’s also not a good idea to leave a Ryobi battery on its charger after it reaches 100%, even if you plan to use it the next day.

While that’s all well-documented advice, the question of leaving your Ryobi charger plugged in all the time doesn’t come up very often. However, if saving money, prolonging the life of your battery charger, and preventing fires are important, it’s something you should think about. Ryobi recommends unplugging its 18-volt chargers and 40V Hyper Charger from the 120-volt power source whenever they’re not in use. The user manual for Ryobi’s 80V Hyper Charger says, “When the tool or battery pack is fully charged, disconnect the charger from the power supply, then disconnect the charger from the tool or battery pack.”

It’s clear that Ryobi doesn’t intend for its battery chargers to remain plugged in all the time. However, we’ll admit that in most cases, it’s more convenient to have your charger plugged in and ready to go. So, what are the risks?

With the high cost of Ryobi batteries, it’s natural to want to extend their lifespan as much as possible. While their corresponding battery chargers are less expensive to replace, having one fail isn’t cheap and could leave you with dead batteries when you need them the most. The electronics inside a Ryobi, or any, battery charger work to convert the 120 volts of AC, alternating current, that comes out of the standard household electrical outlet into the correct DC, direct current, voltage required by the battery it’s designed to charge. When the charger is left plugged into a wall outlet, it stays at the ready, waiting to charge a battery.

While Ryobi’s internal circuitry can minimize power requirements while in stand-by mode, the parasitic electrical usage adds up over time, and the generated heat can cause the charger to age prematurely. Power surges from the electrical grid are another risk to Ryobi chargers left plugged in. When a battery charger that’s plugged in fails, whether in the process of charging a battery or not, it could cause a spark or overheat to the point that it causes a fire. While the risk is relatively low, there is no benefit, other than convenience, to leaving your Ryobi charger plugged in all the time.