When car batteries die after a few years, many people simply discard them and buy replacements.
But with a battery reconditioning charger, you can often bring old batteries back to full charging capacity. Reconditioning saves money while reducing waste. This guide covers how to use these specialty chargers to rejuvenate and restore car batteries.
Table of Contents
- What Does Reconditioning a Car Battery Do?
- Evaluating If Reconditioning Will Work
- DIY Battery Reconditioning Chargers
- Step-By-Step Reconditioning Process
- Checking Voltage and Monitoring Progress
- Maintaining Reconditioned Car Batteries
- When Reconditioning Fails: Disposal and Replacement Tips
- Warning Signs a Battery Needs Reconditioning
What Does Reconditioning a Car Battery Do?
Reconditioning aims to reverse and repair damage from sulfation, a natural deterioration process in lead-acid batteries:
- Sulfate crystals accumulate on the lead battery plates over time.
- This buildup resists flow of electricity, reducing charge capacity.
- Reconditioning breaks down sulfate deposits through controlled discharge/charge cycles.
- Restoring the battery plates allows the battery to hold maximum charge again.
A good reconditioning can restore a dead battery to like-new function. The process works best on newer batteries before excessive sulfation occurs.
Evaluating If Reconditioning Will Work
While reconditioning often succeeds, consider these factors to set expectations:
- Battery age – Up to 4 years old has the best outlook. Really old batteries may not be salvageable.
- Prior usage – Deep discharge and abuse shortens reconditioning effectiveness.
- Physical damage – Cracked case, broken posts, etc. may not be fixable through reconditioning.
- Measured voltage – Generally needs to be at least 5-6 volts to indicate life remaining.
- Desulfation testing – Special meters check internal resistance from sulfation to determine if salvageable.
While results aren’t guaranteed, reconditioning costs little to try before resorting to replacement.
DIY Battery Reconditioning Chargers
These popular chargers allow DIYers to recondition standard 12V lead-acid car batteries:
- NOCO Genius – Well-reviewed model with advanced diagnostics. Simple push-button operation.
- BatteryMINDer Model 2012-AGM – Versatile for both reconditioning and maintenance. For all battery types.
- BLACK+DECKER BC15BD – Budget minded option from a trusted brand. Fully automatic cycling.
- CTEK 56-864 – High end Swedish designed charger with temperature compensation.
- DEWALT DXAEC80 – Heavy duty 8 amp model good for workshop use. Manual and automatic modes.
Follow all directions since methods vary by charger brand. Most provide diagnostics to indicate if the battery can hold a charge again.
Step-By-Step Reconditioning Process
Rejuvenating a dead battery generally involves this straightforward sequence:
- Fully charge the battery if below 12.6V. Damage occurs if reconditioning overly discharged batteries.
- Connect the reconditioning charger leads to the battery terminals. Ensure proper polarity.
- Initiate the reconditioning cycle according to the charger’s directions. This will pulse discharge and charge over several hours.
- Allow the charger to complete all cycles until it indicates the battery is recharged. This may take up to 10 hours.
- Once fully recharged, disconnect the leads and check voltage holding above 12V. The battery is rejuvenated if holding charge.
- Consider additional conditioning cycles for batteries showing further voltage drops after recharging.
With the right charger, bringing an old battery back to full strength is relatively simple. Just be patient through the process.
Checking Voltage and Monitoring Progress
When reconditioning a dead battery, keep track of voltage changes:
- Use a digital voltmeter to check voltage before starting. This provides a baseline.
- Monitor periodically during the discharge/charge cycling. Voltage will drop initially then slowly build back up.
- After recharging completes, let the battery rest 30 minutes. Check voltage again. It should remain above 12V if reconditioned.
- If voltage keeps dropping rapidly after charging, the battery may need more cycles or may be unsalvageable.
Watching voltage clues you into how rejuvenation is progressing. Sudden voltage loss means ending the process.
Maintaining Reconditioned Car Batteries
Once revived, reconditioned batteries require extra care and maintenance:
- Recheck voltage monthly to confirm holding charge. If drops again, do conditioning cycles.
- Avoid deep discharging which strains the repaired battery plates. Use a maintenance charger when storing vehicles.
- Clean terminals regularly since sulfation quickly rebuilds on reconditioned batteries.
- Consider replacing batteries older than 5 years that required reconditioning. Their lifespan is limited.
- Check charging system health to avoid failure from overworked components.
While restored, reconditioned batteries have shorter overall life expectancies than new. Budget for eventual replacement but get all the use possible first.
When Reconditioning Fails: Disposal and Replacement Tips
If a battery won’t take a charge after reconditioning, it must be disposed of properly:
- Some retailersaccept old batteries for recycling. Don’t simply throw in the trash.
- Use gloves and eye protectionwhen handling cracked or leaking batteries. The acid is highly corrosive.
- Try to exchange the old battery for a discount on the new replacement. Some retailers offer this deal.
- Purchase the right replacement ensuring it matches the original’s group size, voltage, and CCA rating.
- Swap it yourself following safety steps or have a shop install the new battery.
Even with a failed reconditioning attempt, you can still get some value from the dead battery before replacing it.
Warning Signs a Battery Needs Reconditioning
Watch for these symptoms of a battery suffering from sulfation that reconditioning may help:
- Difficulty starting, especially in cold weather.
- Dimming headlights when idling.
- Corroded battery terminals.
- Need to frequently recharge the battery.
- Unusual odors from gassing or overheating.
- Loss of reserve capacity and premature voltage drop.
- Battery is 3+ years old.
Catching sulfation early maximizes the chance of successful reconditioning. Don’t wait until the car won’t start.
Equipped with the knowledge of how to properly use a battery reconditioning charger, you can often save the cost of pricey replacements. While not guaranteed, extending battery lifespan through rejuvenation is inexpensive to attempt and offers great upside.