How to check AGM Batteries for problems

Learn how to inspect and care for your AGM Battery

Battery Inspection

The following conditions constitute abusive applications and will void the warranty:          
1. Extreme Vibration applications (i.e., vibrating compactors, concrete cutters)          
2. Dropping or hitting the battery                
3. Cutting, removing, or damaging terminals              
4. Overcharging battery via faulty regulator or dual battery setup not using approved management system    
5. Using Starter battery for deep cycle applications (Car Audio Systems, Trolling Motors, refrigerators)      
6. Opening case lid                
Visual Inspection                  
      Examples that will void Warranty          
Case and cover damage: Cracks or holes in case / cover          
      Missing label            
      Bent cover              
      Shaved or cut cover / case            
      Warped or bubbled cover            
Terminal damage:   Melted, bent or broken terminals          
      Shaved or cut terminals            
      Sunken or raised terminals            
      General Guideline In Testing Batteries              
Initial voltage test                  
a) 00.00V: to 00.90v: Open circuit, Remove from service.  Warranty only applicable it the post has failed  
      or an internal connect breakdown as a result of a manufacturing fault.      
      Internal examination is required.          
b) 1-.20V to 09.98V: Over discharge or application fault. Remove from service. No warranty    
c) 10.00V to 10.98V: Possible broken Inter-cell connecter or straight short. Remove from service.   
      Possible covered under warranty, unless evidence Indications of excessive use or   
      Negative growth which not covered under warranty.        
d) 11.00v to 12.55v: Flat need recharge and retesting. Flat batteries are not covered under warranty.  
e) 12.55V to 12.70V: Fully charged, if fail under load remove from service, warranty applies if within  
      specified warranty period.            
f) 12.70V to 13.00V: low CCA at these voltages is normally an indicator of the Battery being Sulphated &  
      therefore not covered under warranty.  Low CCA is not a manufacturing fault it is   
      more than often an application or customer fault. Batteries are manufactured to an  
      international specification standard from the factory. The Battery will maintain for  
      the majority of its life a reasonable close figure to the rating specified but will   
      reduce in capacity over its life. Many factors may vary the output of the Battery.  
      Using an electronic battery tester is one method of quick testing and should only be  
      used as an indicator as a load-test may be required. Sometimes internal     
      examinations are the only way to determine the fault, but they are costly     
      and time consuming and should only be performed by a Battery Specialist.    
g) Magic Eye MF (Calcium Batteries only)            
      The magic eye is only an indicator, if the battery is charged or not. This test has a  
      30% variance and should only be used as a quick guide.        
      Procedure for testing batteries              
1. Test voltages                  
Refer to General Guidelines In Testing Batteries.              
2. Electronic test Battery                
Use an Electronic style test, if within 15% of CCA capacity put back in service. If low refer to         
General Guideline In Testing Batteries.                
For Electronic testers, they are a guideline only for CCA ratings.            
3. Charge                    
Charge the battery to 100% State-of-Charge if required. Use specified charger to suit the correct battery. (WET, CALCIUM MF,  
AGM, GEL) all require a different peak voltage.              
4. Load test                    
Using a Carbon Pile Load Tester, Load the battery for the specified CCA rating During the first 5 to 10 seconds the battery will  
indicate whether it will pass or fail. The standard time for testing is 30 seconds to 7.20 volts, however this rating is designed   
for a manufacturer to test the first and last battery of each production @ - 18c degrees. To determine whether the production  
is manufactured within the specifications of the rating of the battery. Comments: A Battery load test, will not give the same  
reading as when load tested multiple times.              
Warranty adjudication guide Chances of being a genuine (manufacturing fault)        
1. 4 weeks or under:     5% chance            
2. 1-6 months:     20% chance            
3. 6-12 months:     10% chance            
4. Over 12 months:     5% chance            

Comments (2)


By: on 15 August 2022
It's great that you are sharing useful information. I enjoy reading your blog. David, author, and owner of the blog

What the Batteries do

By: on 10 August 2022
Thanks so much for explaining each possible problem with the voltage variation in deep cycle batteries. My brother has been talking about getting one and wanted to know what I thought. I wanted to learn more about it and how it works.

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