Comments on: Breaking into APC’s BR24BP battery pack

By: Abhijit

Abhijit — Wed, 08 Sep 2010 13:02:21 +0000

Dear Derek,
i also find the same think, the cord for making a BR24BP System. if you find that inform on this page. and improve the document.
thanks for all the guys, for there valuable words.
Thanks

By: Jonathan S.

Jonathan S. — Thu, 26 Aug 2010 23:26:50 +0000

@Loren If you have yet to order, we we actually do have a 9ah replacement in the same form-factor. It can be found here http://www.wholesalebatteriesdirect.com/53663-12v-9ah-UPS-Backup-Battery-replaces-34w-CSB-HR1234WF2-HR-1234W-F2.html

The price is higher than our 8ah, but if you need the 9ah, this is it.

We also carry CSB products (APC’s OEM that gets re-branded with APC name).

By: Loren Pechtel

Loren Pechtel — Sun, 11 Jul 2010 04:25:08 +0000

Another victim of an ailing BR24BP here. This site showed me where to pry and I got it open. Like the other people on here I find poofy batteries, the top ones much more so than the lower ones. (Note: The pack was still operating to some extent but the charge percentage was all over the place in Powerchute.)

Some digging for replacements shows me http://www.wholesalebatteriesdirect.com/45578-apc-rbc33-ups-battery.html these, $80 to do the whole pack although they are 8a batteries rather than the 9a that are in it–a bit shorter runtime. As I just found this I have not yet ordered any and tried them.

As for the resistor I can see another possible explanation: The plug that plugs in the BR24BP appears to be identical to the plug used to connect the battery to the UPS itself. It might be a way of telling the UPS that this is a 24v pack and not a 12v pack.

By: firestorm_v1

firestorm_v1 — Tue, 15 Jun 2010 00:55:15 +0000

Hello John:

Believe me, I feel your pain. I was expecting a complex connector setup for high amperage connections and when I got the connector apart, I was both delighted and dismayed that the connector was so simple. In a pinch, three crimp-on spade connectors and some large diameter wire should get you a temporary patch. If you’re feeling industrious, you could probably build your own connector out of plastic.

Thank you for writing!
FIRESTORM_v1

By: firestorm_v1

firestorm_v1 — Tue, 15 Jun 2010 00:49:58 +0000

Hello Deepesh:

I’m glad that the article was helpful to you. It sounds like you should be able to get good runtime out of that backup however you might take a bit of a runtime hit since you’re changing out the 9AH batteries for 7AH batteries. Either way, it should be more than enough to save against the dreaded power failure. If push comes to shove, install the PowerChute software for Windows and it will give you a lot more information on runtime, total system capacity and current power output.

Good Luck, and let us know how it goes!
FIRESTORM_v1

By: johnwhitmire64

johnwhitmire64 — Thu, 10 Jun 2010 17:25:27 +0000

This helps out, I need to create an extension cord, but you can’t get one from APC. The grey connector is made by Molex, but they do not stock it, especially made for APC and they don’t want to part with them. At least now, I can get this apart and create my own longer cord…

By: Deepesh Rajpal

Deepesh Rajpal — Thu, 03 Jun 2010 20:55:35 +0000

First of All Thank you for a very good guide.

I have a BackUPS RS 1000 IN (India Version output 230 Volts)

Well I just purchased a New Battery Pack in India.

I was unable to find original internal Battery Pack RBC33 here and In my battery pack they used two 9AH (Yes 9AH) of Brand Vision from China.

Nobody was able to provide me 9AH battery here and 7AH was easily available here. So I replaced two of the internal ones with 12V DC 7AH battery and added APC external battery pack also to my BR 1000 IN UPS and waiting for full charge to see how much backup it provides to me. I am expecting a backup of 100-115+ minutes.

By: firestorm_v1

firestorm_v1 — Sat, 27 Feb 2010 07:33:25 +0000

Hey everyone, I wanted to let you all know that I updated the post again with pics of the teardown of the end connector. I hope this helps you all out with the battery pack projects.

After examining it more closely, looks like my initial suspicions of three spade connectors were dead on. It’s the grey connector that makes them easy to connect into the UPS. It can be done manually, however I would recommend an additional layer of shrinkwrap over the crimp ends (the red parts of the spades) so you can use a pair of needlenose to connect them one at a time as safe as possible.

Electrophile – I’m not sure why APC has chosen the two 12V packs in parallel but it seems to carry over with all of their multi-battery installations. Every UPS I have seen that has more than one cell is wired in a 24v configuration.

The yellow wire and resistor go to the GND cable, not the positive cable, which is a bit out of the ordinary. I would think that if they were doing some kind of amperage testing for battery runtime that they would be using the positive lead off of the 24 v arrangement than the GND.

Zorg – You might be right, the resistor might not be a current sensing resistor for loads but rather a safety lockout. If the resistor is there, wrong value or connected to V+ it might throw an alarm and not enable the battery pack at all.

As always, thank you all for your kind comments and the information in your experiences!

FIRESTORM_v1

By: Tyson Brown

Tyson Brown — Tue, 23 Feb 2010 19:11:45 +0000

Also, I found that the plastic tabs holding the front and back plates on were slightly larger than the holes into which they were inserted, which made it necessary to pry them out a bit even if you’re able to drill a hole to push on the tab.

By: Tyson Brown

Tyson Brown — Tue, 23 Feb 2010 19:06:27 +0000

Hi – thanks so much for posting this. It gave me the info I needed to break into my ailing BR24BP. There is one inaccuracy that you’ve posted relating to the batteries – the 3.4A max initial current specification is the maximum current that should be used to charge them when they are substantially discharged. Charging them with a higher current will cause them to overheat and rupture. The 3.4A spec has nothing to do with their capacity, which is going to be given as 7 amp-hours (7AH) based on industry standard rating conventions. With sealed lead acid batteries (a mature technology), capacity is dictated almost entirely by size. If the two 12V batteries are about the same size, they will have about the same capacity.

My BR24BP factory-installed batteries are different than yours – mine have a maximum initial charging current of only 1.7A. They have the same *capacity* (size), but they are not rated for quite as high of a charging current. The UPS’s charging circuit must be designed to limit the charging current to a value that will not exceed the rating of the batteries. Since my factory BR24BP batteries can only handle 1.7A max, I would be able to use any 12V replacement battery that will fit in the BR24BP case and that is rated for a maximum initial [charging] current of 1.7A or greater (2.1A and 3.4A are other values that I’ve seen).