Reviving a 12-Volt Gel Battery Left Uncharged for a Year

Introduction

It's not uncommon for a 12-volt gel battery to be left uncharged for a significant period of time, often due to neglect or a lack of routine maintenance. While such a battery may appear at a loss, there's still a chance it can work again. This article explores the factors that affect the potential for revival and provides a step-by-step guide on how to attempt to revive a gel battery that has been left uncharged for a year.

Factors Affecting the Battery's Revival

Several factors come into play when determining if a uncharged gel battery can be revived:

State of Discharge

The state of discharge is critical. If the battery was deeply discharged below 10.5 volts and left in that state for an extended period, it may suffer from sulfation, which can significantly reduce capacity and lead to permanent damage.

Age and Condition

The overall age and condition of the battery also matter. If the battery was relatively new and in good condition, there's a better chance it can be revived. Older batteries may have more degraded cells and a less efficient charging process.

Charging

Using a suitable charger designed for gel batteries is crucial. Start with a low amp charge to avoid overheating and ensure a stable charging process. Follow the manufacturer's instructions meticulously to avoid potential damage.

Testing

After charging, test the battery using a multimeter. A fully charged gel battery should read around 12.7 to 13.0 volts. If the battery holds a charge and can deliver voltage under load, it may still be usable. However, if the battery shows no signs of recovery, it may need to be replaced.

Maintenance

If the battery does work again, consider periodically checking and maintaining it to prevent future issues. Proper maintenance can extend the battery's life and avoid unexpected failures.

Case Study: A Gel Battery Left Uncharged for a Year

Given that a 12-volt gel battery can still be revived after being left uncharged for a year, some luck can be on your side. Here's a detailed process used to revive a similar situation:

1. Charge Attempt: Initially, attempt to charge the battery using a proper gel battery charger. If the charging process is too slow, try increasing the charge voltage to 18 volts.

2. Observation During Charging: Use a multimeter connected in series with the charger and battery to observe the current. This helps ensure that the charging process proceeds as expected. In some cases, the battery might show a low charge current, which needs to be addressed by keeping it on charge over time. For this, a 12-volt car headlight bulb can be placed in series for safety and to monitor the charging process.

3. Time Factor: In my case, it took about 3 to 4 days to get the battery to charge, indicating that patience and consistency are key in the revival process.

Advanced Revival Techniques

In some cases, additional measures might be necessary to revive a severely degraded battery.

Battery Desulphator

A battery desulphator is a specialized device that can help revive deeply sulfated batteries. Some users have reported success in using such devices:

Example: A couple of 33Ah gel batteries that were stored for about 2 years and tested very low at 4 and 7 Ah were revived to over 20Ah each after a couple of weeks on a trickle charge with a battery desulphator. This method takes time and effort, and the cost of the desulphator must be weighed against the cost of obtaining a new battery.

Conclusion and Disclaimer

While there's always a chance that a gel battery left uncharged for a year can be revived, it's important to approach the situation with realistic expectations. The revival process requires careful consideration of the battery's state, appropriate charging techniques, and patience. If the battery shows no signs of recovery, it may be best to consider replacing it.

Disclaimer: The methods and devices mentioned in this article may not work every time. A battery desulphator can be effective for batteries that were originally in good condition but have been stored for a long time with no maintenance charge. It's essential to weigh the costs and benefits before attempting to revive a battery in this manner.