Undervoltage relay 12volt

[bendyone]

What I want is a relay or switch that will do the following:-

Turn on at 12.75 volts
Turn off at 12 volts.

Will do it 24 hours a day unattended. Load of the relay about 500ma.

What I want to do is run my US anti fouling unit from a 12V battery charged by a wing generator, but if it is windless for a few days and the battery voltage drops I want it to disconnect and then reconnect when the battery has been charged.

 

[Hadenough]

http://www.alfatronix.eu/1575-powertector---full-range-now-available.php

Got a PT 20 on me fridge, works a treat

 

[pelissima]

http://www.alfatronix.eu/1575-powertector---full-range-now-available.php

Got a PT 20 on me fridge, works a treat

Nice piece of kit. Do you happen to remember its price??

 

[bendyone]

Thanks for that just want I wanted, Buy from Farrell at £20 for the 10 amp one.

 

[affinite]

Bendy - Sorry for thread drift but I also have US AF on my boat and have a similar conundrum.
My boat is in the water in Greece and charged on solar but sometimes the sun doesnr shine so I have a similar problem to you re battery drain.
Ive got a big battery bank (500AHr) but rather than risk running the batteries too low Ive been wondering about a dusk-dawn type relay to turn it off the USAF night as I heard that the fouling only occurs during daylight.
Do you know if this is true ?
Rgds Steve

 

[captainboo]

I have used this one for my fridge which can be had even cheaper from ebay. Will switch up to 20 amps between 10.4 & 13.3 volts.

http://cpc.farnell.com/kemo-electronic/m148a/module-battery-guard/dp/HK01170

 

[superheat6k]

I have used this Sontay IO-RMA relay for a similar application at work, but has a working range of 0-10vdc. A higher voltage can be conditioned using a simple dropper resistor circuit i.e. 2 x 50 k ohm centre tapped will reduce a 0-20vdc range to 0-10vdc, so for 11 volts on set the device to 5.5v on, 9v off set 4.5v etc

http://www.vdocshop.com/doc/sontay-ltd/sontay_catalogue_2011/2010122001/17.html