lj_robins wrote:

: I am looking for a schematic for a Belkin F5C520 UPS.

: In case you are wondering and/or can help, output voltage for charging
: the battery is only coming out at 2.4 volts with the battery unhooked
: from the circuit.


Finding a schematic is doubtful.

Don't assume that 2.4v reading without the batteries is incorrect. Most
UPS's don't use a constant charge voltage, it's pulsed on/off on a duty
cycle depending on the current battery charge level.

Unless you tried a fresh set of batteries, it's not really worth the time to
look at the circuitry.

That is the rub, likely the cost of them is going to be 50-75% of the
replacement value of the ups to begin with.

If you really think it has something to do with a LM317 and 2N2222's, those
are nickel/dime parts (if that much) but I really doubt they have anything
to do with the charging circuit.

Belkin already discontinued that model, they have larger capacity ones for
under $100. Most places are selling the battery for the 520 at $41-$49 plus
shipping.

It's just not worth it.

-bruce