To keep the battery safe, always use the charger that came with your remote control vibrator and don't charge it too much. Before you use it, check the battery level and charge it if it's low. Check the remote control and vibrator often for damage or signs of wear, especially around where the batteries go. If you see strange things happening, like short run times or too much heat, you might want to replace the battery or stop using it until it is checked for safety.