Solar water heater (SWH) is an alternative technology to get hot water by using solar energy as an energy source and water as a heat storage media. water has the disadvantage of low energy density for heat storage media. Paraffin wax has a high energy density but a low conductivity value. To fix it with copper powder which has a high thermal conductivity value. The research objective is to obtain the rate of heat absorption in solar water heater tanks using the charging method. Charging is done with the help of a volt regulator as a heater and a pump as an aid in circulating water. The charging process uses a variation of 600; 700; 800; and 900 mLPM until the water temperature in the SWH tank reaches 70 ℃. The data obtained in the form of temperature data for each thermocouple. The data is processed into a cumulative energy graph, a sensible and latent paraffin-CU absorption rate graph, a sensible and latent paraffin-Cu increase rate graph. The results showed the highest absorption rate of latent and sensible paraffin-CU was found in variations of 800 mLPM with values of 234,16 J / s and 62,13 J / s. While the highest rate of latent and sensible paraffin-CU increased at variation of 800 mLPM with values of 12,61 ℃ and 13,48 ℃. So the ideal variation in this research is 800mLPM because it does not require a long time to reach the 70 ℃.