10/08/2026
This question comes up constantly, and the honest answer depends on your charger and the battery's current state. Using a standard 10-amp automotive charger at 80 degrees Fahrenheit, a fully discharged battery will take approximately 8 to 10 hours to reach a full charge.
At lower temperatures, it will take longer. In colder conditions, chemical reactions inside the battery slow down, which means the charging process becomes less efficient. This is why it's so important to charge promptly and not wait until the dead of winter to deal with a battery you knew was struggling in the fall.
Patience now. Power later.
If your battery is struggling, don't wait. Shop replacements at gnbsystems.com or call GNB at 905-549-4454 before the season gets away from you.