Knowing what to avoid is half the battle. Here are the warning signs that should make you drop a product from your shortlist.

• Inflated specs: If the puff count seems too good for the battery size, it's marketing fluff. A 25K puff device needs a substantial battery, typically 800mAh or more.
• Mixed batch reviews: If customer reviews swing wildly between 'works great' and 'died in a day,' that's a consistency problem.
• Charging complaints: Multiple reports of the device not holding a charge or overheating? Walk away.
• Discontinued without notice: If a manufacturer stops a model abruptly, you're stuck with inventory and no support.