OT: Wiring Diagram For APC UPS Battery? (RBC33)

Stupidly, I pulled the two batteries apart without noting the connections -
unaware that I could purchase batteries separately and re-use the wires.

Anybody know where to find the diagram for APC's RBC33 battery pack?

 

It should be possible to download the manual from APC's website
at http://www.apcc.com/.

 

Per Mistoffolees:

That was my first thought - but I haven't been able to find it yet.

 

The manual for my two APC units, does not show the internal battery
wiring, _but_ when you undo the cover, and hinge it out of the way, etched
into the metal plate, is a small wiring diagram. Look very carefully
around the parts that open to let you reach the batteries. Your unit may
have a diagram here.

Best Wishes

 

The manual for my two APC units, does not show the internal battery
wiring, _but_ when you undo the cover, and hinge it out of the way, etched
into the metal plate, is a small wiring diagram. Look very carefully
around the parts that open to let you reach the batteries. Your unit may
have a diagram here.

Best Wishes

 

Try here for the manual:
http://www.apc.com/tools/mytools/index.cfm?action=search&category=user

My APC SU700NET UPS has two 12V batteries in series for 24V operation.

Red wire to Positive of one, Black wire to Negative of the other, plus a
short jumper wire connecting the remaining two pins.

 

Pete,

Based on the cells in my units....
If the question is just how the two batteries are connected to each
other, they are in series, not parallel. ie, each cell produces 6 v so
wire the two so that the pair produces 12 v, the (-) terminal of the
first cell to the (-) connection in the unit, the (+) terminal of the
first cell to the (-) terminal of the second, and the (+) terminal of
the second cell to the (+) connection in the unit.

You should be able to see if yours are the same based on the lettering
on the cells. If they are 6 v cells, then the above should apply.
Charlie Hoffpauir
http://freepages.genealogy.rootsweb.com/~charlieh/
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Batteries should NEVER be wired directly in parallel, so they must be in
series, e.g. positive to negative. Although I've seen stupid examples
of parallel batteries in small consumer devices, USP' are high-powered
applications and would never be designed that way.

[Any two batteries will never have EXACTLY the same voltage, so if you
have two batteries, one might be 6.127 volts and the other 6.125 volts.
If they are wired in parallel, the voltage difference, however small,
will cause current to flow between the two batteries, which is highly
detrimental to everything and which can in some cases be large enough to
cause catastrophic, potentially explosive battery destruction.]

 

Per Barry Watzman:

I guess that answers my unspoken question: Whether the UPS looks at 12 or 24v.

It also matches up with the wires I have laying on the floor: 3 wires.... one
jumper and two to the UPS.

 

Care to elaborate on that?

Batteries are often wired parallel to each other, particularly in backup situations. Case in point, the BR1500 UPS from APC has a power receptacle for a supplemental 24V battery pack BR24BP. It is not wired in series (1st battery wouldn't work alone otherwise). Additionally, APC offers some server UPS solutions that can take up to 10 extra battery packs, all daisy chained together. These are also in parallel.

My understanding is that as long as the batteries are matched at the nominal value, the rectifier circuit neuters any stray currents due to small potential differences across the cells' anodes and cathodes.

Please let me know where I'm wrong...

 

I went to APC.com for my answer

I was so confused after reading this string, I went to APC.com and used "live chat" to get find out how to hook batteries up for an APC SU1000NET. The first person escalated me up to a technician that told me the jumper with the fuse goes in series from negative to positive, with the connectors that run back in the unit going negative to negative and positive to positive.

 

Sorry but I think I need to raise the BS flag.

I have a APC Smart-UPS 3000. It has 8 batteries, in 2 groups of 4.
Of each group of 4, it has 2 batteries in series and the sets are parallel.
Output of each group is 24VDC

The groups of 4 are in series to produce nominal 48VDC.
(this surprised me as I thought all APC UPS's used 24VDC, but I am used to consumer grade UPSes).

This is not some cheap consumer UPS. And it comes from the factory with 8 batteries.

Yes the batteries may not have the same voltage. So what? Nominal voltage for a fully charged 12 VDC battery is a little greater than 12 VDC. For a car battery, with the car running (assuming everything is working correctly), the voltage will be around 14.2. Gel cells like in an APC UPS run a little less voltage while charging. So the battery that started with a lower voltage will charge at a higher current rate than the higher voltage one until it has reached its storage capacity. NOTE I am not saying you can mix different voltage batteries like put a 6V in parallel with a 12V.

A telephone central office will have tens if not hundreds of batteries in parallel.

If you had two 12VDC batteries in parallel, not on a charger, one that was half discharged and one fully charged, you would charge the partially discharged one from the fully charged one until they reach equilibration (if they have the same capacity, both would end up with about a 75% charge).

Just do a Google search on parallel batteries.

But none of this matters, as the UPS in question uses series batteries.

Carl.

 

This is the wiring diagram of a RBC43, not a RBC33. Why am I posting it? Because this page is ranked #3 on google for the term "RBC43 wiring diagram". Also, there is not ONE picture uploaded that actually shows how the wires go if you are doing it from scratch. Okay, I am NOT an expert, but I watched those stupid videos that show people replacing one battery at a time in an existing system and deconstructed how things should be wired, then I turned on the unit and ran the "test" button, it worked. So, now I feel that since I've got 1.5 hours into this I ought to share (novice to expert in 90 minutes?). A bare RBC43 comes with 6 yellow wires, 2 tiny, two med, two long. Lay everything down, obviously, but make sure that pairs of long wires, such as the red wires, are running parallel. If one wire is on the bottom, then it should stay on the bottom all the way through, crossing wires causes them to be too thick to put everything inside the cage.