UPS Batteries? 3

[rirusstek2]

I have a UPS that uses four (4) 6V 12ah batteries connected in series but one of them is on the blink, it only charges to 6.25V the other three fully charged are up to 6.82V thus the UPS does not hold.

I tried it with 3 batteries and it works fine but and holds but for a short period of time.

My question is:

Instead of four 6V 12ah batteries can I replace them with TWO 12V 7ah which are readily available just about everywhere ? (they are used for alarm systems)

On the other hand the 6V 12ah have to be ordered.....

Thanks for any answers .

 

[edfair]

If the 6v are series connected you can replace 2 6s with 1 12v for output. But there are other considerations. The charging circuit is designed for a larger load and it may attempt to over charge the smaller capacity batteries.

You are proposing replacing 48ah of capacity with 14ah, which is less than 1/3 the capacity, and even if the batteries work you will reduce your support time.

If it works with 3 batteries are you sure that the batteries are in series, or could they be combination of series/parallel with 2 parallel sets of 2 in series?

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[rirusstek2]

This is the Actual configuration of four 6V 12aH

NegLEAD--> -BAT+<>-BAT+<>-BAT+<>-BAT+ <--PosLEAD

***
When I use 3 bateries it is like this:

NegLEAD--> -BAT+<>-BAT+<>-BAT+ <--PosLEAD

But it works for shorter times.
***

Now, Is it expected for the system not to work if ONE of the batteries only charges to 6.48 volts and the other 3 to 6.82?

Thanks for your response.

 

[G0AOZ]

Measure the voltages of each battery under load, not when they are being charged. That might give you a completely different story...

ROGER - G0AOZ.

 

[edfair]

You are basically dealing with 24v & 48ah of storage. Putting your 12v batteries in would do the 24 but give 14ah of storage.

I would have expected the UPS to shut down (or not even to start up) with the 3 batteries and 18 volts. Shows how much I know.

I would also have expected the UPS to shut down very early with the one bad battery in the chain. The current draw for the transformer is high and an impaired battery is not capable of passing that kind of current.

Most UPS units have a low battery alarm and shutdown before the battery voltage and current fall off enough to create issues. Evidently yours does not.

Your best bet is to bite the bullet and get an exact replacement.

 

[wahnula]

Your best bet is to bite the bullet and get an exact replacement.

Agreed, but with multi-battery configurations, I'm a believer that when one goes, they all should be replaced. This is not a flashlight, I would assume it's a mission-critical device that your server or other network device depends on. Don't cheap out here; unless the manual clearly states that single batteries can and should be changed then I would recommend that you change them all.

Tony

Users helping Users...

 

[goombawaho]

I would switch to a brand that uses a single battery (less points of failure) and I definitely would screw around with rewiring or replacing batteries with a different combination.

You could burn your house down if things don't go well. Not worth the chance.

 

[rirusstek2]

The lead cable (+) has a tag that reads 40AMPS 32VDC and the compartment has room for six 3.57" x 2.75" x 4" batteries.

It is a Tripp-Lite BC Pro 1050; I have looked in the TrippLite web page for information on it but it seems that there is a "new" model and there is NO reference to the one we have, even the pictures are different.

So, I wonder if I could use six 6Volt batteries in series thus increasing the hold out time?

Any ideas?

Thank you all for your input.

 

[LawnBoy]

You're asking for a fire.

--
The stagehand's axiom: "Never lift what you can drag, never drag what you can roll, never roll what you can leave.

 

[goombawaho]

Agreed - asking for a fire. I mis-spelled above. I meant:

I definitely WOULDN'T screw around with rewiring or replacing batteries with a different combination.

Batteries and the charging system in UPS are designed for each other in terms of amperage, voltage, charging load and rate, etc.

 

[edfair]

I would consider 5 in series and see if it would charge. A 6th would exceed the voltage rating and possibly would not charge.

I'm assuming that the switcher circuits are designed for 32v maximum based on the tag.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[wahnula]

Is this your battery?

http://www.ebatts.com/tripp-lite_bcpro-1050_ups_accessories.aspx

Tony

Users helping Users...

 

[JimInKS]

I get my batteries from here:

http://www.batterywholesale.com/battery-store/proddetail.html?prodID=1146

If you are not in the US then shipping will probably kill you.

And I agree with the above remarks regarding a fire hazard if you do not use the correct voltage and ah capacity replacement batteries.

 

[rirusstek2]

OK, I've sent an e-mail to Tripp-Lite asking for information on this UPS, after they answer, hoping they do, I will ask about the five batteries in series.

The batteries look like the one wahnula showed execpt that they are 12ah instead of 10ah. And the price offered for the ones JimInKS seem like a deal. Battery Plus wants $112 for the set of four.

Thank you all again for all the information and suggestions.

 

[edfair]

And be aware that although most batteries have standardized on 1/4" spade connectors there are some out there that are 3/16". Although the batteries are capable of possibly 40 amp the jumpers themselves with 3/16" spade connectors are questionable. Well, actually questionable at 1/4" spades but I've never heard of one catching the jumpers on fire.

IIRC, I saw some batteries in Wal-Mart or Sams Club recently. I would have remembered which one except I have 2 other sources I use.

 

[rirusstek2]

Yes, Edfair you have a point there, the small spade is not the one to get. In fact, the one battery that is on the blink is the only one with small spade terminals , hummmm!!, maybe it has something to do with the problem battery.

I did notice this about the terminal and tightened the terminals on the cables and let the unit "charge" without any load, but the battery in question does not go over 6.25V

I did find the 12V 7ah batteries in Walmart, which is why I though of repalacing 4 6Volts for 2 12volts and my initial post/question.