We headed with 4 arj on a daily basis till melted, many people who have used these things are aware of the fact that the 20 hours that were promised will play naturally not at 100% volume, and the ambient temperature also depends on this. (i. E. street) It will play 7-8-9 at full speed if there is no overboard and active listening is performed, taking into account any breaks that may occur. If you turn it down a little bit, you will get a sound that is cleaner and crisper. Additionally, you will have longer hours of survival during the day, and in general, the sound quality will last longer.