Charge Before It's Too Late
You can charge NiMH batteries any time you feel like. They lose their power quickly, so you'll probably recharge them a lot. Luckily, it doesn't take that much electricity to charge them. Make sure to remove the charger from the wall socket when you are done charging. Rechargeable alkaline batteries will last longer if they are charged often. A fully depleted battery is a short-lived battery.