Controller Battery Backup?

What about something like a dpdt relay plugged into the wall? When power is on the relay is completing the circuit to a wall wart and when power is cut the relay switches and uses a 12v battery.

It would probably best though to use a dc to dc converter to keep 12v at the controller. I am pretty sure the vortechs and tunzes have that built into their controllers.
 
What about something like a dpdt relay plugged into the wall? When power is on the relay is completing the circuit to a wall wart and when power is cut the relay switches and uses a 12v battery.

It would probably best though to use a dc to dc converter to keep 12v at the controller. I am pretty sure the vortechs and tunzes have that built into their controllers.

I wouldn't see any issue with the controller being supplied voltage less than 12. It's going to be running on 3.3 and 5v circuitry anyhow and will have internal regulators that drop the input voltage. Shouldn't see any problem supplying even down to 9v which would be too low to wan't to take the batteries very often anyhow.

The pumps should be fine also. they might stall at voltage lower than 9v but then they are already being water cooled so I doubt that's much of an issue.

Adding even a very efficient DC to DC boost converter to maintain 12v from the batter will just cut another 10% or so off the run time....
 
It may not be what you are looking for, but I use the APC 1500 back up (model BR1500G)with an added battery pack (BR24BPG-JP) for extended time.

With both, I get about 6-7 hours of Apex and single Tunze 6055 powerhead run time with power outage...just use the Apex to shut everything else off.
 
That's pretty cool. I have that same UPS for my computer. Didn't know they had an additional external battery pack. Of course I only get 3 minutes on my pc but that's enough for it to shut everything down.
 
12v.... 1.5a


At a discharge rate of 1.5a and a 12V 50 amp-hour battery would give you ~33.3333333 hours run time. (Theoretically.) That is a good estimate for Lithium Ion, Lithium Polymer, NiCad, and NiMH batteries. Not so much for alkaline, CZ, LA, LTC, or CC. Some batteries have a big change in capacity, based on how fast they are discharged, and you have to go to the batteries discharge curve in the data sheets.

Translating that to a UPS system, it equates to approximately a 600VA UPS, that will run the load for ~2 hours. (power factor x battery voltage x Ah)/wattage (180 watts; low end UPS power factor 0.6.) Depending on the budget, higher power factor units are common, up to around 0.9.

Using load / power factor / bus voltage (12 volts for a single battery) x factor of 1.3 (due to exponential nature of discharge curves) you are looking at a 32.5Ah battery (standard size would be 35Ah) or a 420VA ups—for one hour run time. Want to go for 8 hours? 8 x 420 = 3360VA. Care to go for 24 hours? These are REAL world numbers.

Just for grins, a 50Ah Li-ion battery will cost around $700.00. Given that, hobbyist DIYers go to LA batteries. I don't want to bring the last debate over DIY UPS systems (and they are ALL UPS systems, albeit lacking in many respects) into this thread, because I think the emphasis is on a commercial solution, and we are not talking about a "large" current draw.

UPS systems are not designed or intended for long term use, rather perhaps up to 10 minutes to provide a window for the safe shut down of electronic equipment. Running them for extended periods of time, is where you start to have problems.
 
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I use a 1KVA for my controller, modem and router. The intent is to have access to critical data, not to power equipment.

If your powerheads are DC, then they would have DC adapters (AC-24VDC) before the pump and can be considered electronic loads. These can likely run off a UPS but watch the power consumption vs. time.

Don't DIY a UPS. Buy a decent value one.
 
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