Stand-by power supply question

[Dave, I can't do that]

Hi people,

I have a Un-Interruptible Power Supply with a dead battery.

Am I correct in thinking that I could remove the dead 7AH gell-cell
and run the wires outside to a bigger battery for longer stand-by time
during an outage?

I have some 25AH batteries here I could use. The 7AH gave me about 5
minutes so would the 25AH give me roughly 3 times as long during an
outage?

Would I also need to add a float charger to the 25AH to supplement any
shortfall in keeping the 25AH fully charged until called upon.

Thanks

Dave

 

[Tom Biasi]

"Dave, I can't do that" <davenpete@gmail.com> wrote in message
news:e3058c18-0eb7-42c2-9ba2-01445619d43d@u18g2000pro.googlegroups.com...

Hi people,

I have a Un-Interruptible Power Supply with a dead battery.

Am I correct in thinking that I could remove the dead 7AH gell-cell
and run the wires outside to a bigger battery for longer stand-by time
during an outage?

I have some 25AH batteries here I could use. The 7AH gave me about 5
minutes so would the 25AH give me roughly 3 times as long during an
outage?

Would I also need to add a float charger to the 25AH to supplement any
shortfall in keeping the 25AH fully charged until called upon.

Thanks

Dave

You are thinking correctly.
Your UPS charging system may not keep the larger batteries in shape.
If you use an auxiliary charger on the larger batteries make sure they are
not conflicting with each other.
You may need some isolation.
Tom

 

[Jamie]

Dave, I can't do that wrote:

Hi people,

I have a Un-Interruptible Power Supply with a dead battery.

Am I correct in thinking that I could remove the dead 7AH gell-cell
and run the wires outside to a bigger battery for longer stand-by time
during an outage?

I have some 25AH batteries here I could use. The 7AH gave me about 5
minutes so would the 25AH give me roughly 3 times as long during an
outage?

Would I also need to add a float charger to the 25AH to supplement any
shortfall in keeping the 25AH fully charged until called upon.

Thanks

Dave
Yes, You can do that. I have done the same thing here. It works very

well how ever, there is a short fall on some UPS units where if a larger
battery is on line it may not see the battery ramping up and current not
retarding. Some units may see this as a damaged battery and fault out.
Also, some units may run a little more heat due to the larger battery
online when charging after commercial is returned, while the load is
still attached..

I've done this with three different units to date and haven't yet see
any issues.


http://webpages.charter.net/jamie_5"

 

[Dave, I can't do that]

On Nov 9, 10:20 am, "Tom Biasi" <tombi...@optonline.net> wrote:

Thanks Tom and Jamie,

Tom, when you say "isolation" what do you mean? My electronics
knowledge is a little limited. I can wield a solder iron and build
stuff but hopeless with design.

Jamie, do you have any brand names to share? I have an APC here.

Thanks guys.

 

[Jamie]

Dave, I can't do that wrote:

On Nov 9, 10:20 am, "Tom Biasi" <tombi...@optonline.net> wrote:

Thanks Tom and Jamie,

Tom, when you say "isolation" what do you mean? My electronics
knowledge is a little limited. I can wield a solder iron and build
stuff but hopeless with design.

Jamie, do you have any brand names to share? I have an APC here.

Thanks guys.
I have 2 different APC's, they both work find with external batteries.

the third is a cheaper flat one, I can't remember the name on it now
but it only cost me 79 bucks, that also works with a larger battery
because all these units had their original battery killed and now I use
batteries I get pulled out of flood lights and so on, when the locale
college refreshes their units.
Its nice to know some one in places like that

http://webpages.charter.net/jamie_5"

 

[terryS]

On Nov 9, 8:33 pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

Dave, I can't do that wrote:

On Nov 9, 10:20 am, "Tom Biasi" <tombi...@optonline.net> wrote:

Thanks Tom and Jamie,

Tom, when you say "isolation" what do you mean? My electronics
knowledge is a little limited. I can wield a solder iron and build
stuff but hopeless with design.

Jamie, do you have any brand names to share? I have an APC here.

Thanks guys.

  I have 2 different APC's, they both work find with external batteries..
  the third is a cheaper flat one, I can't remember the name on it now
but it only cost me 79 bucks, that also works with a larger battery
because all these units had their original battery killed and now I use
batteries I get pulled out of flood lights and so on, when the locale
college refreshes their units.
   Its nice to know some one in places like that

http://webpages.charter.net/jamie_5"

Be careful; understand some UPS batteries can be mains live. Nothing
wrong with that just the way they are designed.
In other words there is no complete isolation between the battery
circuit which is both charged by and when necessary operates the UPS
for a certain period and the mains input/output. The OP's model may
differ.

 

[Peter Hucker]

On Sun, 09 Nov 2008 16:07:48 -0000, Dave, I can't do that <davenpete@gmail.com> wrote:

Hi people,

I have a Un-Interruptible Power Supply with a dead battery.

Am I correct in thinking that I could remove the dead 7AH gell-cell
and run the wires outside to a bigger battery for longer stand-by time
during an outage?

I have some 25AH batteries here I could use. The 7AH gave me about 5
minutes so would the 25AH give me roughly 3 times as long during an
outage?

Would I also need to add a float charger to the 25AH to supplement any
shortfall in keeping the 25AH fully charged until called upon.

Thanks

Dave

Make sure it doesn't overheat. The electronics in the UPS may not be designed to run for long periods.

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