Hetergeneous batteries in Symmetra PX

[ojfsdi]

My PX 80 has 2-year-old 7.2 AH batteries, and some of them are starting to fail a little early.  They are all the same model number, but I've noticed that there is some variation in the markings indicating perhaps not all or them were made in the same location or on the same assembly line.  I'm actually not entirely sure what the minor markings mean.

I've examined the SYBTU1-PLP cartridges after they showed a fault condition, and found some of the batteries inside melted a little!  I carefully extricated the damaged batteries, and I've sourced two 8AH replacements from different manufacturers.  The cheaper ones are harder to get quickly, and the more expensive ones come from a supply house across the street, so I have some of each.

Stamping

Max

Voltage Regulation

Damage

Charge

Standby Use

Cycle Use

Below

Code

Manufacturer

Model

tabs

side

Volt

Ah

HR

Curr.

Low

Hi

Init. Curr.

Low

Hi

Voltage

UPC

Made In

Tabs

AA

Apex

APX1270

AY11AJS2

A180521

12

7

AB

Apex

APX1270

BY11AIY1

A171128

12

7

20

13.7

13.9

<2.1

14.6

14.8

6 83405 42858 9

China

F2 (Large)

Constant Voltage Charge

Valve Regu. Rechargable

Nonspillable

AHH

Apex

APX1270

HHY11AIWa

A171128

12

7

China

F2 (Large)

AHF

Apex

APX1270

HHY11AIWb

A171128

12

7

China

F2 (Large)

B

Bright Way Group

BW1280

HX12-8

(none)

052621FH

12

8

??

???

13.6

13.8

1.2

2.4

14.5

14.9

10.5

8 48050 00170 3

China

F2 (Large)

Replace every 3.5 years

Sealed Lead-Acid Battery

Nonspillable

I

Interstate Batteries

SLA1079

(none)

HVDUL

12

8

20

2.4

13.5

13.8

???

???

14.4

15

???

6 56489 06612 1

Vietnam

F2 (Large)

Sealed Maintenance Free

Nonspillable AGM

I'm wondering what consensus is on mixing different batteries in the same cartridge, 'cartridge pair' A&B or C&D, and shelf.

So far I intend to avoid:

• using different models (which includes amp hours) or ages of batteries in the same cartridge
• using different modeled or aged cartridges on the same 'cartridge pair'

And I intend to keep:

• the same 'blend' of modeled and aged cartridges in the left side (A&B) as is in the right side (C&D) of the battery frame.

Assuming I keep my cartridges clearly marked and labeled, Should I worry about keeping both pairs on the same SHELF identical? 

Or does that not matter itself as long as the blend on all the left shelves is equal to the blend on all the right shelves.

In other words, I'm pretty sure it would be bad for all of the left side to be type a batteries and all of the right side to be type b.  But if half of the cartridge pairs are a and half are b, does it matter on what shelf number I put them on as long as the left side has the same ratio of  a to b as the right side has?

Also, assuming I keep the 'blends' the same on the left and on the right, should I worry about introducing 8AH batteries into a PX that has only known 7.2's?

As you can see in the data table I put together above, the voltage regulation varies a little between each of these batteries.

[al_buffington]

Hi,

Please refer to the following knowledge base article on the subject of users replacing the individual batteries inside the module:

https://www.apc.com/us/en/faqs/FA279266/

Regarding the pairing of batteries based on "type" this article should help you:

https://www.apc.com/us/en/faqs/FA231261/