[Elecraft] Uninterruptible Power Supply for K3S

[Lynn W. Taylor, WB6UUT]

On 7/11/2016 3:41 PM, Bob Nielsen wrote:
> The batteries in my systems probably need replacing.
UPSes typically use some form of VRLA battery.  With computers, they're 
really to bridge short outages or allow a computer to gracefully shut 
down, and the designers assume that power outages are somewhat rare.

If you want these batteries to last, you try to keep the continuous draw 
near or below the ten hour rate -- same as the charging rate. In other 
words, the UPS should last 10 hours with a normal load.

Instead, most last about 15 minutes, and after a few cycles, the 
batteries are fried.

I've removed the internal batteries and replaced them with much larger 
VRLA batteries, often at less than APC or Tripp wants for "proper" 
replacements.

Be sure to use fuses and protect the terminals so you don't hit them 
with something metal accidentally.

VRLA batteries can safely be used indoors.  A big hint is that most of 
these are "UPS shippable."

73 -- Lynn