18.5V Li-Ion Battery Charger with TL431 (short) 

A link to the balance circuits would be appreciated, as all the circuits I saw for sale were for multiple batteries. Thank you for sharing your circuit experiments.

www.bristolwatch.com/ccs/TL431A.htm Experiments with TL431 Shunt Regulator www.bristolwatch.com/ccs/TL431A2.htm TL431A Precision Current Regulator Circuits www.bristolwatch.com/ccs/TL431A3.htm TL431A Based Current Limiter Constant Current Source Circuits www.bristolwatch.com/ccs/TL431A4.htm TL431A Shunt Regulator Circuits www.bristolwatch.com/ccs/lithium_charger.htm TL431A Lithium-Ion Cell Charging Circuits www.bristolwatch.com/ccs/lithium_charger2.htm Charging Multi-Cell Lithium-Ion Battery Packs www.bristolwatch.com/ccs/tl431_ccs1.htm TL431 Over-Voltage, Under-Voltage Detector Circuits www.bristolwatch.com/ccs/tl431_ccs2.htm TL431A Constant Current Source Working Circuits Demo RU-vid: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kJUit6XQYKE.html TL431A Lithium-Ion Cell Charging Circuits ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-jVXmL7HThiM.html TL431 Battery Charger Circuit Calculations Revised ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Fr0Zir8UCLs.html TL431 10-Volt Charger Short Version ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-gg0Tux_pAgk.html Charging, Charge-Balancing 18V Li-Ion Battery with TL431 www.bristolwatch.com/ele4/ccs_lm358.htm Arduino Measures Current from Constant Current Source www.bristolwatch.com/ele4/css.htm Constant Current Source Theory Testing www.bristolwatch.com/ele4/ard_css.htm Arduino Controlled Power Constant Current Source