Datasheet

UC10.241, UC10.242
UC-Series
24V, 15A, CAPACITOR-BASED BUFFER MODULES
11. LIFETIME EXPECTANCY AND MTBF
The lifetime expectancy of the EDLC buffer module is predominantly affected by the storage capacitors. The biggest
influence in lifetime is a combination of operating voltage and operating temperature of these capacitors. To gain
longest lifetimes, PULS does not utilize the full allowed working voltage for these capacitors and therefore accepts a
slightly shorter buffer time.
The EDLC’s do not experience a true end-of-life, rather the capacitance continually degrades over the life of the buffer
module. The typical degradation behavior resembles that of an exponential decay in the first couple of 1000 hours
followed by a linear degradation. The majority of the capacitance reduction occurs during the initial use of the buffer
module and this change in performance then levels off over time. When working with the specified lifetime numbers,
the remaining capacity must always be taken into account. The buffer time correlates linearly to the capacity.
The ultracapacitors have an almost unlimited shelf life (unlike batteries) when stored uncharged at 25°C.
The number of charge/ discharge cycles does not have an impact on the lifetime as long as the number of cycles does
not exceed 100 000. This should not be the case for a typical backup operation.
Lifetime UC10.241 UC10.242
Remaining capacity
85% 75% 85% 75%
Lifetime expectancy
*) 186 000h 324 000h 186 000h 324 000h at 24V, 10A, 25°C
155 000h 270 000h 155 000h 270 000h at 24V, 15A, 25°C
66 000h 115 000h 66 000h 115 000h at 24V, 10A, 40°C
55 000h 96 000h 55 000h 96 000h at 24V, 15A, 40°C
23 000h 40 000h 23 000h 40 000h at 24V, 10A, 55°C
19 000h 34 000h 19 000h 34 000h at 24V, 15A, 55°C
MTBF UC10.241 UC10.242
MTBF
**) SN 29500, IEC 61709 1 519 000h 1 515 000h at 24V, 10A, 25°C
1 443 000h 1 439 000h at 24V, 15A, 25°C
899 000h 895 000h at 24V, 10A, 40°C
954 000h 850 000h at 24V, 15A, 40°C
MTBF
**) MIL HDBK 217F 525 000h 524 000h at 24V, 10A, 25°C; Ground Benign GB25
498 000h 497 000h at 24V, 15A, 25°C; Ground Benign GB25
385 000h 384 000h at 24V, 10A, 40°C; Ground Benign GB40
365 000h 364 000h at 24V, 15A, 40°C; Ground Benign GB40
125 000h 125 000h at 24V, 10A, 25°C; Ground Fixed GF25
118 000h 118 000h at 24V, 15A, 25°C; Ground Fixed GF25
95 000h 95 000h at 24V, 10A, 40°C; Ground Fixed GF40
90 000h 90 000h at 24V, 10A, 40°C; Ground Fixed GF40
*) The Lifetime expectancy shown in the table indicates the minimum operating hours (service life) and is determined by the lifetime
expectancy of the built-in electrolytic capacitors and storage capacitors (ultracapacitors). Lifetime expectancy is specified in operational
hours and is calculated according to the capacitor’s manufacturer specification.
**) MTBF stands for Mean Time Between Failure, which is calculated according to statistical device failures, and indicates reliability of a
device. It is the statistical representation of the likelihood of a unit to fail and does not necessarily represent the life of a product.
The MTBF figure is a statistical representation of the likelihood of a device to fail. A MTBF figure of e.g. 1 000 000h means that
statistically one unit will fail every 100 hours if 10 000 units are installed in the field. However, it can not be determined if the failed unit
has been running for 50 000h or only for 100h.
Apr. 2014 / Rev. 2.0 DS-UC10.241-EN (REVC)
All parameters are specified at 24V, 10A output current, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone [phone] Germany
12/27