12v cutoff circuit

[Utemad]

Hi all,

I am wanting to get a box that will cut off at a certain voltage like 12.2v and cut back in at 13v or so.

The reason for it is to run a 32L Engel fridge off the start battery in my work car.
I don't need dual batteries. I only need to be able to keep the fridge running during a day trip but not to flatten the battery overnight if it is accidently left on.

I know the Traxide SC80 will do it but I only need to switch 5 amps or so. So it would be nice if it was a lot cheaper than that.
I'm happy to make something but being a work car that I don't own and others may drive I'd prefer something off the shelf.

Any ideas?

Any other options people can think of to achieve my goal are most welcome.

[Blknight.aus]

Battery Discharge Protector - Jaycar Electronics (http://www.jaycar.com.au/productView.asp?ID=AA0262)

[Utemad]

Geez I checked Jaycar and didn't see this.

Thanks

[andy_d110]

A WAECO fridge controller does this, about $50 from BCF last time I checked.

[Utemad]

I thought the Waeco fridges except 80 & up had voltage protection built in?
Unfortunately my own fridge is a Waeco 80L so I don't plan on buying any more Waeco products :-(

[slug_burner]

I thought the Waeco fridges except 80 & up had voltage protection built in?
Unfortunately my own fridge is a Waeco 80L so I don't plan on buying any more Waeco products :-(

I have an 80cf and it has the protection you speak of. I take it you have had a bad experience?


Built in three stage
battery protection.

Using the battery monitor.
The device is equipped with a multi-level battery monitor that protects
your vehicle battery against excessive discharging when the device is
connected to the on-board 12/24 V supply.
If the cooler is operated when the vehicle ignition is switched off, the
cooler switches off automatically as soon as the supply voltage falls
below a set level. The cooler will switch back on once the battery has
been recharged to the restart voltage level.

[Utemad]

I guess their coolers don't have the protection.
Mine is about 6-8 years old. Had a few different recurring problems with it which all have the same warm ending.
With mine the three position switch controls compressor power levels not voltage cut off. Even though the manual says it is for voltage cut off. I clarified it with my own tests and a call to Waeco technical assistance.
They must have changed it since then.

[Utemad]

Fitted the Jaycar unit last week. Works well. A little fiddly to set and the spade connectors are a little flimsy but overall it will do the job.