[RFI] UPS with external batteries

[Grant Saviers]

Gary,

I built a EMCOMM cabinet for our condo and it includes a HughesNet 
satellite link requiring 120vac.  The inverter used was
24vdc sine wave inverter 600w samlex PST-600-24a  (FCC class B).  600w 
capacity in case we needed more 120vac for PC's etc.

We haven't noticed RFI on GMRS, 2m, 70cm and HF.  Although we are in a 
high noise environment - downtown Settle, 32 floor, roof antennas.  My 
other experience with Samlex switching power supplies has been good.

Your 5 KWH capacity is quite a battery challenge.  We used 4x 6v golf 
cart batteries (220 AH x 24v) which will keep the sat modem running 
about 24hrs, then a Honda 2kw to recharge.  We also use 2x 6v GC 
batteries for the 12v radios.  Separate 24v and 12v chargers.

Golf cart batteries are the most A-H per dollar. Paralleling batteries 
is not a good idea, so either going to a 48v inverter (not sure Samlex 
makes one) with GC batteries or 24v with L16's or bigger is needed for 5KWH.

A friend's remote camp uses Outback inverter/chargers but they are 3.5KW 
capacity and the battery bank is 8x 6v 500A-H Rolls.   No RFI when I 
operated VHF & HF there.  An important thing to remember is his charging 
power is about 4kw and if the load is another 3kw then a 7kw (8kw Kohler 
propane installed) generator is needed.

Grant KZ1W

On 4/1/2020 21:53, Gary Johnson wrote:
> I'm looking for recommendations on a low-RFI UPS that supports external batteries for extended runtime. It does not have to provide a lot of power, a couple hundred Watts max would be sufficient. But needs to run for more than a day, say >5 kWH. So that’s a pretty good rack of batteries, but do-able.  RFI is the thing. I have yet to find a commercial UPS that has a Part 15 Class B cert. Lots are Class A... Either way, I'd like to hear from anyone who has direct experience.
> 
> -Gary NA6O
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>