[Lowfer] UPS info

[W5JGV]

> the short string on the workings of UPS pointed the use of bigger
> batteries
> to replace ones that go bad. Has there been any problems using bigger
> batteries
> keeping them charged and harming the UPS units

Unless you use a really HUGE battery, the built-in charger will do the
trick.  The recharge time will depend on the ratio of the capacity of
the new battery to the original battery.  Twice as large means twice the
recharge time - of course, that also means twice the run time as well.

It's a good idea to do a test run after you have the new battery
installed.  Load the UPS to near full load and pull the plug out of the
wall.  Carefully watch the temperature of the UPS as it runs.  Some of
the el-cheapo units are designed to run the battery down before they
overheat.  If you put a big battery on them, they may get too hot
without extra cooling.

For example, I have a 550VA APC that I connected a truck battery to, and
it runs FB at full load for over an hour with no overheating.  OTOH, I
have a 1500VA Tripp-Lite that wants forced air cooling of the heat sinks
after about 20 minutes - which is longer than the unit was designed to
run with the factory installed battery.  The transformer, on the other
hand, stays cool.

73,

Ralph   W5JGV - WC2XSR/13

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