First, let’s compare the actual capacity check intervals of Concorde and two other manufacturers (Teledyne and Enersys). Capacity check intervals from Concorde Component Maintenance Manuals (CMMs) are summarized in the following table:
| Battery Application | First Check | Subsequent Checks | |
|---|---|---|---|
| Battery @ 91% or more | Battery @ 85-90% | ||
| Starting Turbine Engines¹ | 12 months/1000 hours | 6 months/500 hours | 3 months/250 hours |
| Starting Piston Engines¹ | 12 months/1000 hours | 12 months/1000 hours | 6 months/500 hours |
| Emergency Back-up | 12 months/1000 hours | 12 months/1000 hours | 6 months/500 hours |
Capacity check intervals from Teledyne CMMs are summarized in the following table:
| Battery Application | First Check | Subsequent Checks |
|---|---|---|
| Generic | 18 months/1800 hours | 9 months/900 hours |
| Bell Helicopters | 11 months/1200 hours | 6 months/600 hours |
| Cessna Mustang & 7243-16T Battery | 12 months/900 hours | 6 months/450 hours |
| Embraer Phenom 100/3006 | 12 months | 6 months |
| Gulfstream 2807 | 11 months/1200 hours | 6 months/600 hours |
Capacity check intervals from Enersys CMM are summarized in the following table:
| Battery Application | First Check | Subsequent Checks | |
|---|---|---|---|
| Battery @ 91 % or more | Battery @ 85-90% | ||
| Generic8 | 18 months/4500 hours | 6 months/1500 hours | 3 months/750 hours |
| Bell 2068 Jetstream 418 Saab 3408 | 12 months/3000 hours | 6 months/1500 hours | 3 months/750 hours |
- Concorde Battery Corporation, 5-0171 Rev Q
- Concorde Battery Corporation, 5-0167 Rev E
- Teledyne Battery Products Q01-1101 Rev. K
- Teledyne Battery Products Q01-2001 Rev. C
- Teledyne Battery Products Q01-3000 Rev. NC
- Teledyne Battery Products Q01-4000 Rev. J
- Teledyne Battery Products Q01-2002 Rev. F
- EnerSys Energy Products 2602-0018 Rev. 5
As seen in the above tables, the main difference is that Concorde’s first check is at 12 months whereas the other manufacturer’s first check is at 18 months for “generic” applications. However, the other manufacturers modify the first check for specific applications and in all cases, it matches Concorde’s first check very closely (11-12 months). So, the main difference is the first check interval for “generic” applications. The other manufacturers start at 18 months, and then shorten the interval once historical data is available. Concorde starts at 12 months, and then allows the interval to be adjusted up or down once historical data is available. Specifically, Concorde has the following note the CMMs:
Examples of how to adjust the capacity check intervals are provided in Concorde’s Technical Bulletin 14, Capacity Check Interval Adjustments. A full copy of the Technical Bulletin is available at: http://www.concordebattery.com/otherpdf/TB14.pdf.
So why doesn’t Concorde change its first check interval to 18 months for “generic” applications? The answer is that Concorde batteries are used in a wide variety of aircraft applications, with unknown duty cycles and operating conditions, some of which may cause the capacity to decline below the minimum airworthiness if the first check was at 18 months. Having the first check at 12 months provides a better guarantee that the battery will stay above the minimum airworthiness condition, even when used in extreme applications.
