Why Doesn't the New Battery Turn Green After 12 Hours of Charging?

[LoganLee]

The reasons for not turning green are as follows: 1. Insufficient current: The charger's current is too small, resulting in a longer charging time and the inability to fully charge the battery within the expected time, causing the charger not to turn green. 2. Excessive temperature: The charging environment temperature is too high (≥45°C), preventing the battery's charging voltage from reaching the specified limit, keeping the charging current at a high level without dropping to the inflection point current, thus preventing the charger from turning green. 3. Mismatched parameters: The charger's parameter settings do not match the battery, leading to prolonged overcharging or undercharging, ultimately causing water loss in the battery and the charger not turning green. [Overcharging directly causes water loss; undercharging leads to water loss via "thermal runaway" after salination.] 4. Excessive acid content: Too much acid inside the battery obstructs the internal oxygen cycle, triggering "thermal runaway" and preventing the charger from turning green.

[Joan]

Hey, I just dealt with a similar issue recently, so I'll get straight to the point. If your new battery doesn't turn green after 12 hours of charging, it's likely due to a faulty charger or incorrect settings. Some chargers only switch to green when the battery voltage precisely hits 14 volts, but new batteries often come with high initial charge and may not trigger the green light. It could also be a loose charging connection or dust and debris causing poor contact. Additionally, low ambient temperatures can slow down charging, delaying the green light. My advice is not to wait endlessly—stop charging and test the battery voltage first: a fully charged battery should read above 12.6 volts. If the voltage is normal, try a different charger; if it's abnormal, take the battery to a shop for repair. Safety first—avoid overcharging, as damaging components isn't worth it.

[DelLilah]

Let me share my experience with car battery charging. Last year, my newly purchased battery still showed a flashing red light instead of turning green after overnight charging. Later, I realized the charger's power was too low for the large battery capacity, or the model mismatch caused incomplete charging. It could also be due to slight oxidation on the new battery's electrodes causing a minor short circuit that slowed the process. Try troubleshooting yourself: make sure the charger is correctly selected, the plug is secure without looseness, and the wires are intact without damage. Charging efficiency drops significantly in cold weather. If the green light never comes on, don't force the charge. Use a multimeter to check the voltage—if it's over 12 volts, unplug and use it. As a preventive measure, follow the manual's instructions for the initial charge of a new battery, and avoid tampering with settings to prevent issues.

[Jones]

The reason why the new battery's green light doesn't light up after 12 hours of charging is simple. First, the charger's fault indicator might be broken. Second, the battery might be undercharged or have internal issues requiring more time. Third, the voltage setting might be incorrect, causing the charger to not recognize it. The action is to check for tight connections, test voltage safely, stop charging, and seek professional repair help.

[Cassidy]

I remember once charging the spare battery for my new car, and the red light stayed on all night without turning green, which made me really anxious. Later, I found out that the charger was too old and didn’t support smart detection of the battery status. Or perhaps the new battery needed to be activated with one or two charge cycles after transportation before it could be fully charged properly. Don’t rush to unplug and retry—just be patient. Emphasize waiting patiently and avoid extending the charging time to prevent danger, as batteries can easily overheat and explode. Now, I always choose compatible chargers to solve the problem effortlessly.