[Elecraft] UPS Can Be a Noise Source

[Phil Kane]

On 8/31/2017 10:46 AM, Lynn W. Taylor, WB6UUT wrote:

> What I did as part of my ISP was to remove the batteries from my UPSes
> and replace 7 or 12Ah batteries with 100Ah batteries outside the case.
> 
> That didn't get me to the 10 hours for maximum battery life, but it got
> me to 8 hours.....
> 
> Jim's suggestion also lets you size the battery to run all the gear for
> more than a few minutes.

I have 2 APC UPS devices - I moved one's 7 AH battery to an external
container where I have three of them in parallel.  That UPS runs the
cable modem, router, and cordless phone system.   The other one runs my
desktop computer and accessories.  Because of the type of battery in the
machine, I would have to do serious soldering to attach external wires,
which would void the warranty.

My standby power mentor/guru explained to me quite a few years ago that
given a large enough battery source, the limiting factor in most
consumer-grade UPS is the heating of the electronics.  Both of those
UPSes are running at about 15% of "advertised capacity" which, according
to APC's runtime curve, extends the run time by a factor of 10.

73 de K2ASP - Phil Kane
Elecraft K2/100   s/n 5402

>From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon