Hi @adigitaldj1 ,
Thank you for contacting Digi-Key TechForum.
Building such a circuit would involve some engineering. If you are to take on that task, This article would be a good read to get started. These charger chips might fit your need, please review datasheet specifications to determine if they will suit your application.
Otherwise 1568-PRT-16793-ND is a great charger if you decide to purchase one, 1939-1237-ND power supply and 1847-PC-ABK001F-ND power cable would be compatible for it.