Review on Kerjthu Coffee Mug Warmer, Intelligent Cup Warmer for Desk Beverage with 2 Temperature Settings, Auto Shut Off Electric Tea Warmer & Candle Warmer Plate for Home Office Use by Michelle Larson

I bought this to replace a 20 year old spark plug heater that was showing signs of wear. I use a coffee candle warmer. Since I could tell the candle heater was losing power, I needed something new to keep my coffee hot. It wasn't an answer. It's definitely not nearly as warm as advertised. Maybe it would be better on a thin but metallic mug, but I use regular coffee mugs every day. I used it for two days and really felt that the coffee cools down much faster than on the old heating pad. So today I did a little experiment. I heated both heaters for the same amount of time, then used two identical cups with the same amount of microwaved water. Both cups were 167° when I placed them side by side on the heating pads. After 10 minutes the new heater was 139° and the old 141°. After 35 minutes the old one was at 123° and the new one at 118°. It's amazing how important these 5° are. At the one-hour mark, the old reading was 115° and the new reading was 118°. At the three-hour mark, the old one was 109.5 and the new one was 99°. I also noticed that around the three o'clock mark the bottom of the cup felt quite hot on the old heating pad, while it was just warm on the new heating pad. Even when I used it with an active cup of coffee, the device kept turning off. This is one of the reasons I did the experiment because I thought that turning it off might make the coffee colder. I don't know if my hand accidentally touched the power button while putting down a cup of coffee or something. I will return this item.