I like the Meanwell AD-155 too. Simple and cheap.
I read about the Traco TSP on this list (probably from George) and I've
been very happy with it.
The BCM has a temperature sensor that you tape to the batteries and then
it can automatically adjust the charging voltage according to
temperature. Temperature compensation is an important feature if the
enclosure/building isn't going to stay at 70F all the time, and it will
extend your battery life.....climate control would extend your battery
life even better, but sometimes you take what you can get.
There are also a bunch of relay closures you can read with a Site
Monitor switch input. You can then be notified about AC power being out
and battery failure. Oh yeah, and there's a relay contact that will
power cycle the whole system. That might come in handy someday.
I would still use the meanwell (or similar float charger) when it has to
be cheap and the 150W is enough.
On 3/9/2016 3:21 PM, George Skorup wrote:
The AD-155 is 150W max load.
What I would do is a Traco TSP 48v power supply (180, 240, 360 or
600W), a TSP-BCMU360 in 48v mode and a Mean Well 48 to 24 RSD. The
BCMU360 takes a 12v SLA and does an internal DC-DC conversion. I
haven't had any problems with them. I have two in the field right now
maintaining 37Ah Deka's.
On 3/9/2016 2:06 PM, SmarterBroadband wrote:
That Meanwell sounds right. I will have to see if they make a more
powerful one?
*From:*Af [mailto:[email protected]] *On Behalf Of *Mathew Howard
*Sent:* Wednesday, March 09, 2016 11:39 AM
*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]
<mailto:[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 <mailto:[email protected]>
*Sent:*Wednesday, March 09, 2016 11:45 AM
*To:*[email protected] <mailto:[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.
