Thread: Battery Management

Oh yes what is the best for the 2nd battery - in english please, I going to put in in one of those boxes fro supercheap in the rear of vehicle. (not under the bonnet)

ummmm that wasnt the best explination of my setup...

currently I have the main battery looked after by the alternator

I have a battery manager hanging off of this

I have an auxillary battery hanging on the manager

The camper trailer setup has a battery that hooks up parallel to the auxillary battery(via the power outlet sockets. The camper trailer has the solar panels..

Unless I turn the ignition on, When they are charging the auxillaries there is no charge getting to the main battery.

Thats what Im curious about sorting out, ATM Its not a problem but its something that sitting in the back of my mind giving me the "theres got to be a better way" jabs...

Ideally what I want is whenever theres voltage higher than the main batteries voltage it gets a sniff of it to keep it absolutely 100%. As soon as the voltage dips the main battery gets isolated. Several people have offered the solution of putting the panels on the rover and wiring to the main, me included but SWMBO has put the kybosh on that and the panels are to stay on the trailer. And Im all out of pins on the trailer plug to be able to wire them up to the main battery through that.

Hi ladas, the statement you made about not draining you cranking battery is a common request but there is actually no reason, with the right controller, why you can’t take advantage of the surplus power available in your cranking battery without causing any problems with starting the vehicle, as normal.

Now this is going to sound like an advertisement ( and it is ) but both the SC40 and SC80 were designed to not only work as dual battery isolators but were specifically designed with the added advantage of using the surplus power in the cranking battery to extend the operating time of the auxiliary battery.

It’s not just a simple case of setting the cut-out voltage to a lower monitored level.

Your Sure Power, Redarc, ARB, TJM, Supercheap and so on, type dual battery switches all do the job they are designed for and do it well, but the are designed to automatically switch on when they sense the motor has started ( as is the case with the SC40 and SC80 ) and then to automatically switch off when they sense the motor has stopped.

But, these devices are restricted to doing just that. Although a number of these devices can be set up to switch off at lower voltages, their own current consumption is their biggest restriction against using these device for lower voltage sensing.

They all consume between 0.6 and 0.8 of an amp to keep them powered and power consumption is fine while the motor is running, but once the motor is off and these devices are now being powered by the batteries, on average, this would amounts to around 15 amps a day would be needed just to keep the isolator powered, before any accessories are powered.

Now, for Defenders, Disco 1s and 2s and to an even greater extent for D3s, all where auxiliary batteries can be restricted to a small size, to use one of these other devices would be of little advantage as they themselves would chew up most of the extra power available from the cranking battery.

This is where the SC40 and SC80 differ. The SC80, which is designed to control the charge of one large or two additional batteries, requires only about 0.24 amps ( less than 6 amps a day ) and the SC40 requires only 0.12 amps ( 3 amps a day ), so far, far less of the power is required to power the these controllers and this is why they will add, on average, around 50% more operating capacity to your existing auxiliary battery.

Cheers.

Originally Posted by Blknight.aus

currently I have the main battery looked after by the alternator

I have a battery manager hanging off of this

I have an auxillary battery hanging on the manager

The camper trailer has the solar panels..

Hi Dave, what size are your solar panels and what type of “ battery manager “ have you got?

Almost understand the explanation - so how much is the kit, and what battery as a second would you recommend.

Hi again ladas and everybody else. Owing to the large number of enquiries I get for Dual Battery Systems for Defenders, thanks to the assistance of X-Box and his Defender, I have begun a new project in the PROJECTS & TUTORIALS SECTION.

Although PROJECT 4 will be based primarily on a Defender installation, it will easily suite other vehicles, so I will now recommend we continue this thread in the PROJECTS & TUTORIALS SECTION, at

http://www.aulro.com/afvb/showthread...768#post463768