[time-nuts] Re: Backup DC power with current battery technology?

[John Ackermann N8UR]

On 5/27/24 11:59, Tom Van Baak via time-nuts wrote:

> I make 
> heavy use of Powerpole connectors for everything: batteries, clocks, 
> extension cables, and chargers.

I've been using PowerPoles on everything DC for years.  Color coding 
and/or keying for different voltages is interesting.  Red is universally 
used for 12V, and it seems that orange is common for 24V and that's what 
I use.  Beyond that, it's a free-for-all.  I've been using a lot of 5V 
lately for SDRs, RPis, and such and have standardized on green for that. 
  I currently don't have anything running on 48 volts so am not sure if 
there's a standard for that.  However I'm currently using yellow for 
variable-voltage power supplies and general-purpose leads to indicate
"check me first".

> I tried using double conversion UPS systems but they were 
> expensive, noisy, and ate batteries.

When I built my current lab and had to put in AC power to various 
places, I got a used 3.1KVA UPS with 220V input and split phase output, 
and an external battery pack for extra run time.  It's semi-hardwired 
into a closet in the basement with output going to a six 110V circuit 
subpanel that drives outlets throughout the lab area.  It's "semi" 
hardwired because there are RV-type mating connector pairs on input and 
output that let the UPS be bypassed relatively easily.

That has worked very well, but after seven years all the batteries -- 
UPS, 24V, and 12V are about exhausted so it's a good time to re-engineer.

John