Can I charge a Lead Acid Battery with a Lithium Ion Battery
$begingroup$ IF it is a 4S LiIon charger the battery is nominal 4x 3.6 = 14.4V BUT the charger will charge to a peak of 4.2 x 4 = 16.8V. SO follow it with a Constant voltage unit and it will charge to whatever CV you set. 13.7V is safe for floating a