There seem to be different opinions on the appropriate cutoff point for
LVD also. I recall a 12V Morningstar solar controller had an 11.2V
LVD. On one of the common DIN UPS modules it's 10.9V (Traco I think,
though I might be muddling that with a Meanwell spec sheet in my head).
That's roughly speaking 75% discharge vs 90% discharge. Either way it
affects your run time and you ought to plan on it.
Some here have expressed that they would rather buy new batteries than
be down, so they avoid LVD completely.
On 12/2/2015 1:24 PM, Ken Hohhof wrote:
A good way to avoid confusion is to convert to convert to watt-hours.
I’m assuming when you say 400Ah, you probably have 12V batteries and
are adding up the Ah ratings of all the batteries. Like maybe 4
batteries, each 12V and 100Ah. Although there are certainly other
common battery voltages like 2V and 6V.
So I look at a typical 12V battery rated 100Ah, multiply them and get
1200 watt-hours. If you have 4 of them, it’s 4800 watt-hours no
matter how you hook them up parallel, series, or some combination.
That’s how much energy is stored in those batteries when fully charged.
So in rough numbers, a 500 watt load will drain a ~5000 watt-hour
battery bank in ~10 hours, assuming you are running the loads directly
off the batteries, with no conversion loss due to an inverter or DC-DC
converter.
And as someone pointed out, you need to check what depth of discharge
the 100Ah is rated at. If that’s 100% discharged, the battery life is
going to be severely degraded. Also likely you may have a low voltage
disconnect (LVD) that will disconnect the loads before you get to that
point, in order to protect the batteries.
*From:* Bill Prince <mailto:part15...@gmail.com>
*Sent:* Wednesday, December 02, 2015 12:05 PM
*To:* af@afmug.com <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] Calculating battery bank size
wrong.
bp
<part15sbs{at}gmail{dot}com>
On 12/2/2015 10:04 AM, Josh Luthman wrote:
If you do 4x 12v 100ah batteries and do 24v it's twice the time as 48v
Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
On Dec 2, 2015 1:01 PM, "Bill Prince" <part15...@gmail.com
<mailto:part15...@gmail.com>> wrote:
What voltage?
bp
<part15sbs{at}gmail{dot}com>
On 12/2/2015 10:00 AM, TJ Trout wrote:
How long will 500w load last on 400ah?
