Hello @ScheduleDisplay
my M5Paper starting with a flat battery returns the following numbers when the battery is charged (read every second):
3976, 3986, 3990, 3998, 4002, 4008, 4014, 4020, 4022, 4026, 4030, 4038, 4044, 4046, 4052, 4060, 4060, 4068, 4070, 4070, 4076, 4078, 4078, 4090, 4092, 4094, 4098, 4102, 4104, 4108, 4114, 4114, 4116, 4120, 4122, 4124, 4126, 4126, 4130, 4134, 4136, 4142, 4142, 4148, 4150, 4152, 4154, 4156, 4162, 4160, 4164, 4168, 4170, 4174, 4176, 4176, 4176, 4178, 4180, 4182, 4184, 4186, 4188, 4192, 4194, 4196, 4196, 4198, 4200, 4204, 4204, 4206, 4210, 4210, 4212, 4214, 4218, 4218, 4224, 4226, 4226, 4226, 4226, 4228, 4228, 4228, 4230, 4232, 4230, 4236, 4238, 4240, 4242, 4244, 4244, 4246, 4246, 4250, 4252, 4252, 4256, 4254, 4254, 4258, 4258, 4258, 4262, 4266, 4264, 4266, 4268, 4268, 4270, 4276, 4274, 4276, 4276, 4276, 4276, 4278,
I suspect that in your case, reading 4.35 V, the battery was almost full.
Thanks
Felix