Low Voltage Diconnect (LVD)

Ta Richard,

I'll have a look around. Did you have to fit a solenoid as well or is the device fully opertional and able to handle the battery current.

Rosscoe,

The unit is fully self-contained so no additional solenoid is required. It did come with cig plug & socket which I just cut off and then I hard-wired the unit into my circuit.

The max current it can handle is 10amps.

Richard

I have a Deep cycle battery as the main - and only - battery in my Forester. I bought a deep cycle as my 3 way frig draws about 7A and I was told that this amount of drain would ruin a 'normal' battery? I use a Projector cut out unit on the frig and it cuts out at 11.6 V which is plenty enough power to start a 2.0 L petrol motor. I haven't timed it, but the battery will run the frig for about 2 hours before the Projector cuts in (out).
I also use 'hella' type plugs and I cut the wires back fairly short.

Ian
What David is implying is that by running a separate feed cable for the fridge, it is only carrying the fridge current, reducing the volt drop in the cable allowing a higher voltage to be available for the fridge that would otherwise be the case.
The two cables are joined at the alt's output terminal, so the fridge still sees the battery.

Thanks Guys,

The Projecta unit, as far as I can tell, is not adjustable but that's OK. I can use it as a warning signal and manually bypass it if necessary. I do run a 150W inverter from time to time (Notebook PC and TV) so I'll need to watch the 10A limit.
As David has inferred, there are two problems with lead acid batteries. Firstly, repeated deep discharge shortens their life dramatically and secondly, the normal alternator/voltage regulator system in the vehicle can only achieve about 80% charge. You can't fiddle with the regulator out put because modern computer based engine management sytems require a specific voltage level.

The LVD question I posed here and the answer is only part of the solution but non-the less, a very good way of getting reasonable economical life from my deep cycle battery.

Because we are dealing with a low voltage system voltage drop across cable is critical for effective operation of some appliances e.g. 3-way asorption fridges. I think I have this under control.
Now I'm going to start working on charging the batteries as close as practically possible to 100%.

Even with 240V AC available unless I use a smart charger I won't achieve this.

So it looks like shelling out more dollars on a microprocessor based smart charger (Approx. $300) and/or Solar panels with an appropriato solar controller (> $1000).
In the mean time I just have to be very carefull with the way I use power and limit the time I can stay in the bush without mains.

Glenn,

Can you please expand a little please.

With my solar regulator it has three connections, one for Solar Cell, one for the batery and one for the output.

So the regulator not only handles the solar cell charging the battery, it also cuts off the output when the battery gets to 40%.

So if you dont have a Solar cell now but might get one in the future, you could use the regulator now and plug a solar cell on later.