Bottle warmer recommendations

currently using a brand called jiffi (bought from taobao) now. one good thing is that it has a version where the battery capacity is 9000mah, larger than most others in the market and I can use it entire day for at least 3 to 5 times without recharging. it also has the option of buying with uv sterilizer cap where you can use to sterilize the inner metal panel, instead of just wiping and using hot water to heat it for a few seconds. However not sure about other brands, but I tried heating up a 140ml milk bottle from around 10degrees to 40 degrees and it took more than 10 minutes.