Why DC?

[sirhc]

Another quick note, if your towers are in an area that gets COLD during the winter, I recommend using an insulated and heated NEMA box (powered off 120VAC). You WILL LOSE up to 80% capacity/runtime if the temp gets below zero and you have a power outage. I keep my batteries warm (50-60 degrees), and they WILL retain the heat when the power goes out, and give you more runtime.

This is true but better quality AGM batteries do much better than wet cell automotive batteries.

[lligetfa]

Some folks bury their battery boxes in the soil to keep them cool in Summer and warmer in Winter. Obviously then one needs to take care not to let the pit flood.

[wispwest]

I only use AGM's, its definitely worth the extra cost. They say not to discharge wet batteries lower than 80%, as it can damage them, not to mention its hard to get full capacity ever again. I've had people tell ask me "why aren't you using MARINE batteries", why are you using "scooter" batteries???? And I have to try and explain to them the big difference between AGM's.

Car batteries are designed for "lots of power all at once" (cranking amps), and to be re-charged immediately. AGM's are designed to give lower amps, longer period of time and can be discharged down to 40% or so without damaging or decreasing the battery life. I did SERIOUS study to this when making my RV trailer off-grid with solar.

Xantrex, makes a device you could install as well, which monitors your power usage and calculates runtime and shows % battery life remaining, including temp probe for batteries, but you wouldn't be able to "login" and see the runtime remotely :( maybe you could get an AirCam and point it at it lol

[sirhc]

Yes fully discharging any battery "can" result in damage or decreased capacity but newer especially AGM batteries are design with the understanding that they will be fully discharged every now and then but it is recommended NOT to do this as a rule of thumb.

Our WS-12-250-DC will allow you to FULLY discharge a bank of 4 12V batteries hooked in series to produce 48V all the way down to 9V or 2.25V per battery which is FULLY discharged but we are not putting a gun to users head telling them that they have to but in an emergency you can tell the switch to stay up at all costs if the switch is hooked directly to the battery bank.

Let say you get a message from one of our switches and it says it will be shutting off soon because the 48V battery bank is reaching 43V and that is what you have it set to discharge to before shutting off but it is 2AM so with our switch you can log into it and say go ahead and stay up.

WARNING: If you FULLY discharge a battery even some AGM you need a special charger capable of 10A per battery to recover which I have at my sites as they are ON GRID.

If you are OFF grid you might have to travel to the site with a generator and charger to recover but you can schedule this visit at your leisure the next day or 2 instead of 2AM.

[wispwest]

Chris, so in theory, if I started using the SMART DC, I would get longer run-time? What about the Tycon battery chargers/auto-transfer modules? I would just go away with using those all together, and just wire a 48V battery charger to the batteries, totally separate from the SMART DC switch, and connect the switch 48V to the batteries, then when power goes off, the charger dumps offline completely, and the switch uses every last drop of the batteries it can, all the way down to 9VDC correct?

I'm starting to like this....

[sirhc]

Chris, so in theory, if I started using the SMART DC, I would get longer run-time? What about the Tycon battery chargers/auto-transfer modules? I would just go away with using those all together, and just wire a 48V battery charger to the batteries, totally separate from the SMART DC switch, and connect the switch 48V to the batteries, then when power goes off, the charger dumps offline completely, and the switch uses every last drop of the batteries it can, all the way down to 9VDC correct?

I'm starting to like this....

YUP, that is the idea of the SMART switch models WS-8-250-DC which is EOL and WS-12-250-DC which is in MASS production right now