How many 9V gadgets do you have around the shop — or the house? Let’s count: there’s the studfinder, the moisture meter, the fox-and-hound wire tracer, a handful of multimeters, a flashlight, a transistor radio. Wow. The list goes on and on! I’m a big advocate of rechargeable batteries, but the nickel-based chemistries aren’t ideal for most nine-volt applications. Now there’s an alternative: Lithium!
Nine-volt batteries aren’t known for their vast capacity or cost-effectiveness, so they typically fill standby applications where just a trickle of power is needed — and where the high voltage simplifies the device’s circuitry. But sometimes their compact size means they end up in applications like flashlights and intercoms, where they don’t last very long because of their low capacity. Using rechargeables in these devices can save money — and landfill space.
Unlike nickel-cadmium and nickel-metal hydride rechargeables, the new lithium-polymer 9V batteries actually offer more capacity than the alkalines they replace — 500 mAh in the lithium versus 150-200 mAh for NiMH and 300-490mAh for alkaline. They also perform better at low temperatures, and can sustain a higher discharge rate.
But the real kicker is that they exhibit very low self-discharge, the annoying property that made older chemistries inappropriate for most of the applications where nine-volt batteries and up installed.
If you work in a studio, these are the batteries you want in your intercoms, wireless mics, and other gadgetry! And at a street price of around $15, they’ll pay for themselves many times over before reaching the end of their 500-cycle lifespan. The charger sells for $35 or so, and will also charge older 8.4-volt NiCd and NiMH rechargeables, if you have ’em around.