Wireless Charging Question

[benhath]

With an S6 and either a Verizon charging plate or a Nokia Dt-900, the lamp on the charger comes on when placing the phone on the plate,
goes off when the phone indicates 100% charge and the green LED illuminates, but 5 or so minutes later the charging light comes back on and stays on. The phone does not change status nor indicates it wants more of a charge.

My S4 had behaved differently. Once the charger lamp went off, it stayed off. I know that the phone cuts off the battery so there won't be any damage but I wondered if anyone else has experienced this?

Thanks
Ben