Bottle warmer recommendations

I'm using the wireless bottle warmer from nicepapa, bought from shopee. It depends on heating panels in the warmer to heat up the milk, and takes about an hr to go from fridge cold milk to warm. I use it if I'm running on shorter trips out. Put warmed milk in the warmer to conserve the batt, and then when finished, put the next bottle in so tt there's time to slowly warm. This one takes pre-planning since the heating is slow. battery can last for 1 heat up from cold to warm, and 1 preserved warm bottle before needing to be charged. Good for my usage thus far. I spent about $40. I'm assuming you're asking about portable bottle warmers and not those tt u use at home haha.