I have several Belkin Model F6C120-UNV UPS units in need of repair.
These are 1200VA UPS units designed for 120VAC type operation. Can
anyone recommend where schematics for these may be obtained?

If it turns out that the repair needed is simply to replace the sealed
lead acid batteries in these units is it generally considered cost
effective to do so or is one better off just getting a new unit.

- mkaras

On Wed, 7 Jan 2009 15:01:46 -0800 (PST), mkaras
wrote:

I have several Belkin Model F6C120-UNV UPS units in need of repair.
These are 1200VA UPS units designed for 120VAC type operation. Can
anyone recommend where schematics for these may be obtained?

The most common fault with small "domestic/SOHO" UPS is battery dying due to
overcharging and drying of the electrolyte. Assuming the behaviour of these
units is consistent with that, replace the batteries.

Sometimes fuses fail, sometimes the electronics fail. But batteries are far
more often the issue.

Quickest test is to substitute an automobile battery (or as many in series as is
required to achieve the DC system voltage) and test the system.

If it turns out that the repair needed is simply to replace the sealed
lead acid batteries in these units is it generally considered cost
effective to do so or is one better off just getting a new unit.

I'd always replace the batteries rather than the whole UPS if:

.. the rest of the unit is sound and provides the capacity and functionality
required; and

.. there aren't "bells and whistles" on current models that are considered
desirable.

The only other matter - which does require a schematic - is to determine whether
the charge regime is being unnecessarily brutal on the batteries and causing
their premature demise.

On Jan 7, 5:41*pm, rebel wrote:
On Wed, 7 Jan 2009 15:01:46 -0800 (PST), mkaras
wrote:

I have several Belkin Model F6C120-UNV UPS units in need of repair.
These are 1200VA UPS units designed for 120VAC type operation. Can
anyone recommend where schematics for these may be obtained?

The most common fault with small "domestic/SOHO" UPS is battery dying due to
overcharging and drying of the electrolyte. *Assuming the behaviour of these
units is consistent with that, replace the batteries.

Sometimes fuses fail, sometimes the electronics fail. *But batteries are far
more often the issue.

Quickest test is to substitute an automobile battery (or as many in series as is
required to achieve the DC system voltage) and test the system.

If it turns out that the repair needed is simply to replace the sealed
lead acid batteries in these units is it generally considered cost
effective to do so or is one better off just getting a new unit.

I'd always replace the batteries rather than the whole UPS if:

. *the rest of the unit is sound and provides the capacity and functionality
required; and

. *there aren't "bells and whistles" on current models that are considered
desirable.

The only other matter - which does require a schematic - is to determine whether
the charge regime is being unnecessarily brutal on the batteries and causing
their premature demise.

That's funny, I just came here and started a similar thread.
http://groups.google.com/group/sci.e...1180dc38cc7881

The battery in mine went belly up. A new 12 V 7.0 a/hr sealed lead/
acid battery for mine is $38 at the local electranics store, or $ 20 +
shipping on-line.

On Wed, 7 Jan 2009 15:01:46 -0800 (PST), mkaras
wrote:

I have several Belkin Model F6C120-UNV UPS units in need of repair.
These are 1200VA UPS units designed for 120VAC type operation. Can
anyone recommend where schematics for these may be obtained?

If it turns out that the repair needed is simply to replace the sealed
lead acid batteries in these units is it generally considered cost
effective to do so or is one better off just getting a new unit.

- mkaras

It is usually always the batteries.

IMHO, if not batteries then junk the unit. Belkin is not a high
quality name, IMHO.

mkaras wrote:
I have several Belkin Model F6C120-UNV UPS units in need of repair.

Thanks folks for the replies. I disassembled one of the UPS units (a
unit in service since 2004 or so that failed about 4 months ago).
Inside it looks clean except the batteries are completely dead. If
particular interest is bulging of the sides of the battery cases. I'll
try getting two of units of these 12V/7.5AH sealed batteries (appears
like a bog standard type of battery) and see how that works.

I want to watch battery cost even though these things were about $180
US when new. A quick look seems that locally at Batteries Plus the
replacements are about $33 US each for the "Werker" brand. Mouser web
site shows an equivalent Panasonic unit at $39 US each but then there
is shipping on top that.

- mkaras

It's probably smarter to put about 4 car batteries in the basement on a
trickle charger and use an inverter *and put USP outlets near your
computer stuff. You can use a relay to switch on the inverter and
outlets to backup power on power loss.

If you keep out the relay you get an on-line UPS, but you need a 12V
supply that can provide the required amps. I have found that
regulating the voltage to 13,5V keeps the batteries charged without
gassing.

On Thu, 8 Jan 2009 16:49:34 -0800 (PST), mkaras
wrote:

mkaras wrote:
I have several Belkin Model F6C120-UNV UPS units in need of repair.

Thanks folks for the replies. I disassembled one of the UPS units (a
unit in service since 2004 or so that failed about 4 months ago).
Inside it looks clean except the batteries are completely dead. If
particular interest is bulging of the sides of the battery cases.

A sure sign of overcharging, electrolyte drying, and heat damage.

I'll
try getting two of units of these 12V/7.5AH sealed batteries (appears
like a bog standard type of battery) and see how that works.

If you don't attend to the charging circuitry you'll get the same outcome.

The comment from Van Chocstraw illustrates the problem:

"I put 2 motorcycle batteries in series and put
them beside the UPS. Drilled a hole in the UPS and ran a wire to the
battery terminals. Works like a charm though it DOES tend to Overcharge
the batteries. They bubble all the time and dry out. Have to keep adding
water."

The manufacturers aim to recharge the batteries in the absolute minimum time
(often with the absolute least-component-count chargers) with the argument that
the next AC supply outage could be very soon. The casualty of this thinking and
poor charger design is battery life expectancy.

Hell, I have a piece of communications test equipment that was ~$US18K new. The
battery charger in these was sub-standard and all owners I know have to replace
the batteries every two or three years. I reworked the charge system many years
ago and haven't had a problem since.

I want to watch battery cost even though these things were about $180
US when new. A quick look seems that locally at Batteries Plus the
replacements are about $33 US each for the "Werker" brand. Mouser web
site shows an equivalent Panasonic unit at $39 US each but then there
is shipping on top that.