The illustration on this page shows the layout circuit of a typical lead acid charger. In this case, when the charge current falls to 0.1A, the charger switches to a 13.5V float charge mode. Then the charger re-initiates the 14.4V fast charge mode if the battery voltage falls below 13.2V. Also, the LT3652 trickle charges at 0.15A if the battery voltage falls below 10V. This solution features a 0°C to 45°C battery temperature charging range.