How the die battery affect UPS

[StevenX]

1. We have a SMX3000LVNC which is connecting 4 external SMX120BP which was bought 11 years ago, we temporarily name these four external pack as Bat1, Bat2, Bat3 and Bat4. If battery in Bat2 dies, how many battery pack will continue support UPS? Only Bat1 or Bat1 plus Bat3 and Bat4?

2. We want to buy new batteries to replace the old battery in SMX120BP. 

What's the new battery model compatible with SMX120BP and SMX3000LVNC?

How can I replace batter safety and while replacement, do I need to power off SMX3000LVNC? 

[Teken]

How the system behaves depends upon many factors such as if all RBC are the same health, installation date, and capacity.

If all RBC are truly 11 years old that is absolutely ridiculous and someone needs to be fired! 🤦‍♂️

The RBC is rated to provide 2-5 years of service life based on usage, temperature, and environmental conditions. They are designed to sustain 260 cycles before degradation is seen.

The best case scenario is you will see shorter operational runtime. Worst case the bad cells in each RBC will drag down other RBC and cause the system to shutdown. 

In the extreme cases the RBC will bulge, over heat, vent, and cause an explosive situation if there is a electrical spark.

Im not sure what you mean by newer battery model?!? The APC OEM is RBC143 so if the question is about rebuilding the RBC then you can simply purchase ten of the same CSB 12 VDC 5 AH cells and rebuild it which is much cheaper than buying two RBC cartridges.

Lastly, the SMX is hot swappable as such you do not need to power down the system. The only caveat is (IF) the RBC’s are dead during a power outage / disruption the system will obviously shutdown as the RBC can’t sustain the connected loads.

So either replace the RBC pairs from top down in sequence or rebuild the RBC and replace them the same way as outlined above.

Once all RBC have been replaced update the battery installation date in the system. Mark the same on every RBC cartridge on the face.

Manually initiate a self test and let pass and allow the system to return to 100% SOC (State of Charge).

Complete the process by manually initiating a battery calibration with at least 30% or greater attached load. Once completed allow the system to fully charge the entire battery pack / system.

The operational runtime will be more accurately displayed via LCD, NMC, SNMP

Questions Ask . . . 👍

[StevenX]

Hello Teken, I googled CSB 12 VDC 5 AH cell, and got many battery models. Which battery model is APC filling into SMX120BP? 

[StevenX]

As my understand, multiple SMX120BP is connected in parallel, inside cells are connected in serial so if one cell dies, it will make the host SMX120BP stop working, so that master smart UPS like our SMX3000LVNC will lost some battery running time, not all SMX120BP support. Am I correct?

[Teken]

You may refer to this CSB Resource Link for the individual cells inside of the RBC:

https://csb-battery.ca/products/hr1221wf2

As stated what happens depends upon what state (condition) the individual cells within the RBC (Replacement Battery Cartridge) are in.

In the extreme case where the RBC is completely dead if there is an outage and requires the system to transfer to battery only power.

The system will drop the attached loads and shutdown. In a best case scenario depending upon actual load you’ll see a few minutes (1-5) of operational runtime vs the expected of whatever say 30-60 minutes.

Any serious enterprise installation will perform daily, monthly, yearly maintenance and inspections of the power delivery management systems.

This spans from very basic visual inspection of the LCD parameters, UPS frame, input / output wiring / identification, connected loads, and logs.

To battery production & installations date, RBC inspection of cartridges, etc.

Annual Static & Dynamic load testing is conducted to validate the entire system is fully operational and ready to perform when needed. This also encompasses validating all cells within the RBC are still within the battery manufacturers internal resistance values so the expected minimum operational runtime is obtained during a lights out / grid down event.

Questions Ask . . . 👍