I prefer to build it out of discrete components. From: Mathew Howard Sent: Wednesday, March 09, 2016 12:38 PM To: af Subject: Re: [AFMUG] Small DC Site
Is there really any advantage to using something like an AD-155B with a UPS function over just connecting the batteries in parallel with the load to a normal DC power supply and setting the voltage properly? It seems like there would be less parts to fail and it'd be easier to add redundancy if the batteries were just connected in parallel. On Wed, Mar 9, 2016 at 12:52 PM, Chuck McCown <[email protected]> wrote: A pair of power supplies that are capable of pulling the load and charging the battery. For example, if you needed 200 watts for your 24 volt loads, you need 8.3 amps. Round that up to 10 amps. Then you have to decide how long you want this thing to last without commercial power. I would think 24 hours is a minimum. So 10 amps x 24 hours is 240 amp hours of battery. It is always a safe figure to charge a battery at .1C or 10% of its capacity or less. That would be 24 amps to charge the batts after a power outage, plus 10 for load = 34 amps of power supply. You could get by with 20 amps, just will take a bit longer to charge. Lots of 20 amp 28VDC power supplies out there. Rule of thumb double your load power or more to size the charger. From: SmarterBroadband Sent: Wednesday, March 09, 2016 11:45 AM To: [email protected] Subject: [AFMUG] Small DC Site What are people using to power small DC sites. Option 1 up to 150 - 200 Watts, option 2 up to 300 – 400 Watts. I’m looking for a DC UPS that can charge attached batteries. Need to have 24 and 48 volt.
