UPS Battery Battery Sizing

1. UPS BatteryBattery Sizing Paolo Frisoni Application Engineer, DPG Liebert Hiross UPS

2. Battery Sizing • Type of batteries used in DPG UPS • Batteries for extended runtime • How to assess backup times and size extra batteries • Special requirements (NiCd, 10 Years) • Other requirements

3. Battery Sizing Battery Used for micro UPS / On-Line For GXT2-3000RT230 a 15 Amp. 72V Battery Charger (same look) is available its PN is: GXT2-1000RBC.072

4. Battery Sizing Battery Used for micro UPS - Off Line

5. Battery Sizing Battery Used for small UPS

6. Battery Sizing • Battery Used for Micro & Small UPS • The most part of our products use : • Valve regulated lead-acid battery 5 Years of life • Blocks of 12Volt (6 cell on each) with 7-7.2Ah • The dimension are standard for different supplier but the terminals must be Fast-on 6,3 mm • Hinet and its Batt.Cab. can be supplied without internal batteries. The internal Batt.Charger provide 1 - 3.5 -7Amp • A complete Kit of Battery cable can be provided for the internal connections (HNBATTCABLE) • The GXT 5&10kVA can be supplied without internal Batteries the PN is GXT5000T-230NB & GXT10000T-230NB with improved Battery Charger (4,5Amp)

7. Battery Sizing • Battery Used for 10 Years Applications • For special requirements like 10 Years Battery • for 12V 7Ah Blocks • The NP7-12 (Yuasa) can be replaced with the RE7-12 the increasing cost is 70% • for 12V 38Ah Blocks • The NP38-12 (Yuasa) can be replaced with NPL38-12 cost increase 15% • for 12V 65Ah Block • The NP65-12 (Yuasa) can be replaced with NPL65-12 cost increase 15%

8. Battery Sizing Key Factors in Battery Life There are 4 factor that strongly affect the Battery Life • Ambient Temperature • Number of Charge/Discharge Cycles • Deep discharge • Floating Charge Voltage @ Temperature

9. Battery Sizing • AMBIENT TEMPERATURE Effect of the Temperature on Lifetime

10. Battery Sizing • Number of Charge/Discharge Cycles • Depend on number of Deep Discharge Cycles (%) • We will reach the DDL only when the Main fail last more than the UPS autonomy

11. Battery Sizing • Deep Discharge • The lowest recommended Voltage Under Load were the Battery can works or Cut off Voltage • Below this limit Battery will be damaged • UPS Topology also lead to cycle on to battery operation frequently • OFF-LINE Worse • LINE INTERACTIVE Less Worse • ON-LINE Best Behaviour

12. Battery Sizing • Deep Discharge • Some UPS the Cut Off voltage can be adjusted, like Hinet (The default Value is 1.66 V/cell) • Some others UPS this Limit change automatically with the load (all GXT series)

13. Battery Sizing • Float Charge Voltage versus Temperature • Float Charge Voltage need to be maintained between 2.275V/cell +/- 0.005 (at 20°C) • For Hinet is adjustable (factory set to 2.25 V) • For GXT is Fixed to 2.3V • Optimisation will be reached when this value is adjusted with temperature : • at 0°C V/cell = 2,35V • at 40°C V/cell = 2,15V • Hinet --> next step • Improvement

14. Design Criteria Run Time Calculator • This Tool perform the calculation of Run Time of the UPS for a given: • Power of Load (kW) • Battery Capacity (Ah) • It work on Excel • It is based on the Lead Acid Discharge Curves • it optimise the calculation of autonomy time for the battery that is considered working down to Deep Discharge limit for a given current • gives tested results

15. Design Criteria Run Time Calculator • The Standard Capacity nominal value of a battery is for 20 Hours of discharge time to a final voltage of 1.75V per cell • The nominal capacity of a battery is reduced when is discharged at value of current that exceed the 20-Hour discharge rate • That means the real Capacity you can extract from the Battery is: k * C where is a reduction coefficient k < 1 How does the Calculator works: • Input: • Load Power (kW) • Battery Capacity (Ah) • Nominal Battery Voltage • Output : • the Run Time for the assigned Capacity (Ah)

16. Design Criteria Run Time Calculator

17. Design Criteria Run Time Calculator It performs the calculation of the Battery Current: Then the Ratio of the Battery Current and the Battery Capacity This value is Located On the Deep Discharge Characteristic this is a non linear passage , the K coefficient is so detected

18. Design Criteria Run Time Calculator Finally the Run time is calculated Like : Output

19. Design Criteria Run Time Calculator • Accuracy GXT Internal Deep. Disch. Char.

20. Battery Sizing • Some Autonomy Data

21. Battery Sizing • Some Autonomy Data

22. Battery Sizing • Some Autonomy Data

23. Battery Sizing • Some Autonomy Data for GXT + 2x 240VBATT Batt.Cab.

24. Battery Sizing • Some Autonomy Data for GXT + 240VLRT Batt.Cab.

25. Battery Sizing • GXT6000 (1x1 & 3x1) can be extended with the limitation of two Cabinet 240VBATT max - for Thermal reason • GXT8000 3X1 & GXT10000 (1x1 & 3x1) can be extended either with Cabinet 240VBATT and Cabinet 240VLRT • The max numbers of Cabinets depend by the allowed recharging time ( the Batt. Charger rating is 1.5Amp) • If more than two Cabinets 240VLRT are necessary then is recommended to use the GXT5000T-230NB & GXT10000T-230NB with improved Battery Charger (4,5Amp) . But they are not CE certified

26. Battery Sizing • Some Autonomy Data for Hinet with Batt.Cab.

27. Battery Sizing • Ni-Cd Battery • Some application require high life despite of the price (Very High Price !!) • The Voltage/Cell for Ni-Cd Batt. change like this: • 1,4 V/el in Floating • 1,07 V/el in end of Discharge • If you have an UPS design with Lead Acid Battery to switch with Ni-Cd is necessary to increase the Number of Cells in the same ratio as the V/el • For instance Hinet requires 192 Cells in Pb and for Ni-Cd 192* (2,25/1,4) = 308 Ni-Cd Cells

28. Battery Sizing • Ni-Cd Battery • The Low Battery Limit must be adjusted in the same way • 308* 1,07 = 329 Volt • Hinet allow to easily adjust these limits so it’s open to be supplied with Ni-Cd Batteries. • The recharge current for Ni-Cd Battery must be well regulated • The Hinet Battery charger feed a constant current that can be 1- 3.5 - 7 Amp up to Floating Point were the Float voltage will be held Fixed.

29. Nfinity Extended Batt. Cabinet • This Cabinet Allow to use the same Intelligent Battery Module of Nfinity frame • P/N is N900Exx00000 • It is a Matching Cabinet • Need two Intellislot Battery Card (IBC), • 1on Nfinity, 1 on the Cabinet + serial cable for communication • 2 shipped with each Extended Battery Cabinet • The DC Power connection cable • P/Ns: NPNPEXTBC3, NPNPEXTBC15 • These include specially designed connectors • In the UPS configuration Menu select : • Change Settings (press <Return>) • Intellislot Battery Cabinet (press <Return>) • enter the quantity of extended Battery Cabinet installed • press Return and ESC

30. Nfinity External Batt. Cabinet • Can 10 years batteries be used? • Not inside the main UPS Frame • Only 5 years Battery Modules are designed for Nfinity UPS • By using the External Battery Cabinet: • New version has same front bezels as Nfinity • Cabinet type: CZ1 Size 90Ah/120V with Battery Charger • Batteries Used are Power Batteries SLF12105 • Note the difference between: External Battery Cabinet and Extended Battery Cabinet • External BC is not an “Intelligent” backed up Battery • does not use Nfinity Battery Modules • the Battery Module will not disconnect from the others when a failure is detected

31. Battery Sizing • EXTERNAL BATTERY CABINET CZ1 the Old and New one

32. Battery Sizing • Where is the Battery charger ? • located in the Power Module • the charger has a temperature compensation with a current limited to 3,2A • Others functions of the Power Module are: • Power Factor Correction Circuit working with PWM at 20kHz. • Input Power Factor close to 0,99 (see following slide) • Output Inverter • Starting from version G3 (mid-2002) : Able to accept three phase and single phase input line • Older G2 modules cannot be fitted in new 3x1 frames

33. Thank you for your attention For more questions contact: Product Support Desk on http://my.liebert-hiross.com