The 12V Force Charge Mode is specially designed for low-voltage batteries. When a 12V battery's voltage is between 0.3V and 2V, this means that the battery has aged or been damaged to some extent. Therefore, it may not be effectively charged with the 9-step charging process.
In this case, the Sigma 1 battery charger will force charge your battery for 5 minutes and restore the voltage of your battery to a normal state as much as possible.
How to enter the 12V Force Charge Mode:
1) Connect the clamps/eyelets to the charger and to your battery.
2) Plug the charger into an electrical outlet.
3) Press the Confirm button to enter a 5-minute force charge.
Caution: This icon will flash automatically only when the connected battery voltage is between 0.3V and 2V and 12V, 12V AGM or 12V LiPo mode is selected.
Note: Generally speaking, the battery voltage can be restored to more than 2V through the 5-minute forced charging after which the battery can be charged with the regular 9-step charging mode. However, due to the inconsistency in the degree of aging or sulfation of the battery, there is no guarantee that the battery will be restored to a good condition by a 5-minute forced charging mode.