Solid State Dual Battery Isolator/Control

[PRS]

Has anyone used this Solid State (MOSFET switched) dual battery isolator?

Voltage Sensing Relays | Intervolt (http://www.intervolt.com/product/voltage-sensing-relays/#horizontalTab3)

Most of the spec look rather good, with only 0.5mOhm resistance (MOSFET at 25degC). This would equate to about 1.5watt of heating at 50 Amp load. 35mA current draw in the ON state and 10mA for the OFF state.
Looking at the wiring would expect the negative could be disconnected/switched to get this to 0mA.

The On/Off voltage levels as with On/Off time delays are user adjustable. Great !
Expect the settings would be held should there be a power loss as the specification makes mention of default settings.

One down side in the temperature rating 150A at 40degC. Would need to look at the temperature de-rating.

Has any member had experience with this unit.

The vehicle has a garaged load of 190mA of which the vast majority is the present dual battery device relay (until it drops below the 12.0 volt). This solid state unit would reduce the garaged current by 75 to 80%.
Overcomes the need for connecting the battery charger if not used for a week. Great if this was extended to a month plus. Must be better for the life of the AGM batteries.

Paul

[Tombie]

What are you currently running?

[PRS]

Traxide SC80

[Tombie]

If you're having to charge after a week running that you have something very odd going on...

I have the USI-160 and can park up for 3+ weeks without a problem.

[dswatts]

I'm running one of the Intervolt VSR's. Made 3 ks away from where I live. Great unit, easy to change the connect and disconnect voltages as well as delay times.

Dylan

[Tombie]

I'm not questioning the unit - I am questioning how the OPs vehicle is running down so much in a week...

[drivesafe]

Hi PRS, and as Tombie posted, you should be able to go a lot longer than a week before needing to charge batteries.

The most common cause of this type of issue is short driving trips and/or not driving enough.

Both are now common practice with a lot of RV vehicle owners, not just Land Rovers, and to cater for this, the second generation SC80s now have the same TIME-OUT feature that the USI-160 has had for the last few years.

3 days after the motor was last running, the SC80 TIMES OUT and shuts down.

Automatically solves the problem of leaving the vehicle unused for long periods.

NOTE, all SC80s supplied from April the 1st this year have this and a number of other features as standard.

[PRS]

Tombie, thanks for your interest and suggestions.
took a few readings this morning.
SC80 On state at 12.6 volt draws 190mA
8-14mA Off State (LED flashing)
The ABG25 module draws a further 95mA in the On state
this totals 285mA for the Traxide system.
Not easy to take a current reading of the vehicle in "sleep" mode as the ammeter has a 10A quick acting fuse, which I suspect is not adequate to handle the door locking inrush current which is required for sleep mode.
The 285mA represents 48 AH for a week in the garage.

Sure there is more in the batteries, however my understanding is AGM/LA batteries have better life when kept in a fully charged state.
I monitor the battery voltage and connect the Projecta IC2500 charger, limited to 12A and set for AGM, when down to 12.0 to 12.1 volt.
Total battery capacity is 95+55AH =150AH giving 60AH if cycling 50 to 90% SOC. I have not included in the above figures any parasitic load of the vehicle (a MY13 RSS) in the above figures.
The Optima yellow top is 2 years old and the cranking AGM was replaced 2 months ago, prior to a 8000kM outback trip, as previous unit had reduced storage capacity. Down to less than 50%.

Hence, my interest in possible replacement of isolating devices with solid state units.
The ABG25 could be replaced with a Zeva LVC12 unit which draws only 4mA in the On the state, and good for 50amp continuous with a resistance of only 0.001mOhm.
This being another solid state device. The down side is it requires a manual reset.

Going solid state instead of the Traxide two devices would reduce the load from 285mA to 40mA.

Understand the USI-160 you have has the 3 day timer, opening the isolator and hence reducing the load. Would also suggest the USI-160 would draw more current in the On state catering for the increased relay capacity.

Tim thanks for your reply but feel a bit burnt in having a SC80 only 2 years old and having to "update". Then what of the ABG25 ?

Cheers, Paul

[drivesafe]

Tim thanks for your reply but feel a bit burnt in having a SC80 only 2 years old and having to "update".

Hi Paul, and the SC80 update is the first in over 25 years of production of the original SC80, and the update came about, as I posted above, to address similar situations like yours.

Your type of vehicle use, while not the norm, is, as I pointed out earlier, becoming more common, hence the upgrade.

BTW, from it's inception 4 years ago, the ABG-25 already has a 72 hour TIME-OUT as part of it's operation. And again, this was incorporated in it's operation, to reduce battery energy wastage in those few vehicles that are not driven all that much.

Paul, I was not suggesting you should update your SC80, just pointing out, the newest generation of the SC80 now caters for your type of usage.

Also be aware, if you decide to install the other isolator, remember, you are still going to have to charge your batteries on a regular basis, maybe not as often, because of your driving habits.

That brings me to another feature in the new SC80s, and that is the ability to REVERSE-CHARGE, after the SC80 has turned off. Again, this feature was added to cater for people who, like yourself, do not drive their vehicles all that often.

[CU55TM Disco]

That intervolt unit looks suspicious similar to this jaycar unit that they are clearing out.

https://www.jaycar.com.au/120a-12-24vdc-programmable-dual-battery-isolator/p/MB3688

[Tombie]

Doesn't it just!!!

Very similar specs so the basis is the same.

Wonder if it's coincidence or the great big photocopier?

[PRS]

Looks Soooo very much the same. As Tombie suggests that big photocopier has had a workout. Way too much the same even the default settings.
The Intervolt unit does however have a better spec with less current draw in open and closed states, less voltage drop across the MOSFET.
From their web site looks like it has been around for a few years.
Paul

[drivesafe]

Paul, before you do anything else, can I make a suggestion?

Try cutting the thin green earth wire on your SC80, and fit a switch to it.

Then when you know you are not going to be using your Disco for a while, turn the switch off.

As I pointed out earlier, I think you are still going to have low battery problems.

With one of my original SC80 isolators and fully charged batteries, you should get at least 3 to 4 weeks before the isolator turns off. NOTE at this point your cranking battery should still be at 50% SoC ( 12.0v ).

From what you have posted, you are your own worst enemy and I don't mean that in a derogatory way. You do not drive your vehicle enough to not only fully charge your batteries, but also to maintain them in a good condition.

As I have already posted, this is becoming an all too common situation with many vehicle owners, not just Land Rovers, but the problem does seem to by more prolific with Land Rovers.

Whether you change the isolator or remove it altogether, it will not resolve your problem, but it may ease it a bit.

Again, try powering down the SC80 when you are not using your Disco for long periods, and see if it improves your battery state.