Diagnosing Starting issues: Battery or Charger
Starting issues in home standby generators can arise from various sources, such as battery and charger problems or other mechanical issues. This guide provides a systematic approach to differentiate between these problems, with an emphasis on the importance of situational awareness and seeking professional help when necessary.
Checking the battery is a fundamental first step in troubleshooting generator starting issues. However, differentiating between battery, charger, and other mechanical issues requires careful consideration of the symptoms and external factors. For persistent or unclear issues, especially with new installations, consulting a professional is crucial for a safe and accurate resolution.
Environment
This article applies to all Guardian air-cooled Home Standby Generators 10 kW – 26 kW.
Troubleshooting Flow
The guide aims to assist in diagnosing common generator starting issues and is for informational purposes only. Electrical systems can be complex and dangerous. If in doubt or if issues, continue, it’s essential to seek professional assistance. Prioritize safety and adhere to the owner’s manual guidelines to prevent potential equipment damage.
1. Initial assessment
- If the generator cranks but doesn’t start, the issue is likely not with the battery.
- If it does not crank in automatic mode, try starting in manual mode.
2. Manual Mode Testing
- Cranking in manual mode but not starting usually indicates a non-battery issue.
- Failure to crank in manual mode suggests a potential battery or connection issue.
3. Battery Health Check
- Check the battery’s health status in the controller menu.
- Measure the battery voltage with a multimeter. A fully charged 12V battery should show around 12.6V.
- Review the controller’s history for alarms indicating charging issues.
4. Investigate Battery and Charging System
- For a completely dead battery, inspect the T1 customer connection at the generator and automatic transfer switch. 120VAC. Check for the charging circuit neutral if applicable.
- Check the T1 Fuse for damage, as a blown fuse can interrupt the charging circuit.
Additional troubleshooting
RPM Sensor Loss Alarm
This alarm might suggest a battery issue if the unit fails to crank. If the unit cranks look beyond the battery for issues.
Situational Factors
Old battery: When is the last time the battery has been inspected or replaced? Battery inspection is a part of routine yearly maintenance, and batteries typically last between 3 and 5 years.
Battery in low charge state: Low batteries before utility outages or during prolonged outages might not recharge or have a chance to recharge since the battery is charged using utility power.
Low ambient temperature: Cold weather can affect battery performance, see the article on cold weather kits and battery warmer pads. If applicable.
Faults alarms: “Charger Missing AC” warnings are expected during outages and are not indicative of charger faults.
Considerations for New Installs
Wiring Checks: New installations are prone to wiring issues. Ensure all connections are secure and correctly configured according to the installation manual. See My Generator was just installed and is giving a "Charger Warning" or "Charger Missing AC Warning" for more information.
Initial Charge cycle: New batteries might require an initial 18-hour charge cycle to fully charge, even if the battery is new.
Battery Charge: Some new batteries may require a charge before the first use to ensure optimal performance.
Blank Display - Dead Battery
A dead battery may be the result of a defective battery, problems with the charging circuit, or a blown fuse.
If the 7.5 AMP controller fuse is blown, the controller's charging mechanism is unable to function, thus preventing the battery from going on a charge cycle. Over time this can result in a low, very low, or dead battery.
If the battery is dead, you will need to remove the battery replace or use an appropriate battery charger see battery manufacturer guidelines.
