dual battery system

[BCF Lurker Find all posts View Profile Close BCF]

I've settled on a Lead Acid Marine Battery as the Aux with a BCDC1220 charger under the bonnet. The Redarc has a small heat shield around it and has good airflow.

One thing the battery folks stressed was to put the battery on a good 7 stage charger every 2 months at a minimum. Unless you are going long distances in your car regularly the battery will never fully top up. Easiest way is put a 50amp anderson on the front of the car somewhere ie: bullbar and plug the charger directly into it, saves the need to open the bonnet all the time....We fill up every 2 months in the diesel 120 and that reminds me to plug in the charger.....

Pete

Thanks for the good tip re adding a plug to make topping up the battery.
Can you please advise where you located your BCDC to gain good airflow? A picture would help.
BCF...

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Another thing to consider if you go the way of a DCDC charger, recent customer was
telling me of his problem with his current setup, he has an optima yellow top for an aux
in the car and an other brand AGM in his camper.

He recently did the Canning stock route and pointed out he was having trouble trying to keep the batteries charged and the fridge running. Problem was all the stop start, drive for 20 minutes then have to stop to tackle sand dunes etc.

I pointed out to him if he got rid of the charger (20A bottle neck) fitted a booster diode to his Prado he would have been able to bring the Optima up to 95% SOC in a little over and hours running time and he would not have had any problems. He is now pulling out the DCDC charger and replacing it with a standard VSR.

Cheers
Leigh

[D4D Addicted PP Member Find all posts View Profile Close D4D]

I pointed out to him if he got rid of the charger (20A bottle neck) fitted a booster diode to his Prado he would have been able to bring the Optima up to 95% SOC in a little over and hours running time and he would not have had any problems.

Yup, I am running twin Optimas and I can get them both back to 100% from 70% in under an hour of driving on a D4D with Leigh's V booster, stock alternator and ARB (Surepower) VSR.

[demomanca Junior Member Find all posts View Profile Close demomanca]

So as not to fire up another thread, just to you let you all know, I've just installed a dual battery system from ARB (Redarc SB12, Exide MSDP27 battery) and I wanted a way to monitor the battery usage from inside the car. I didn't really want 2 x 52mm gauges (or even 1 for that matter) and I stumbled across these fellas

http://www.peelinstruments.com.au/page18.html

I got the volt meter off ebay (from http://www.ebay.com.au/usr/wrfc63 ) for $50, and I'll install it on the weekend and report back as to how well (or not well) it works.

I have to say however, the guys selling them went above and beyond, as they hadn't tried a 120 Prado to see if it fits, but they said they found one to make sure it would fit.

[peril Senior Member Find all posts View Profile Close peril]

I installed a Baintech duel voltmeter, not as cheep as yours but I like the digital readouts personally. It fitted perfectly into the space where the air suspension control sits in the Grande, just to the left of the steering column.

[brooksy78 Member Find all posts View Profile Close brooksy78]

Sidewinder do a good voltmeter

[demomanca Junior Member Find all posts View Profile Close demomanca]

Here's the finished product installed. I'm pretty happy with it, works as advertised.

Quick question about it though, I installed the + connections behind fuses, will that alter the reading much?

[demomanca Junior Member Find all posts View Profile Close demomanca]

Ok, my install is working great, but I've hit a bit of a snag.

I ordered a switch to override the Redarc SBI12 (wired up correctly and working). The switch also has a globe (12v bulb, not an LED) that I wired up with the 1kohm resister (as per Redarc instructions) to indicate when it was active. The globe doesn't light up, even though it has 12v across it. I'm assuming it's because the Redarc doesn't output enough juice from that cable to power a globe, only a LED (manual indicated 15mW output).

On this basis, I assume to get the light to work, I'll have to either a) replace it with an LED, which might be a bit tricky without destroying the switch or b) rig up some sort of relay. I'm not very savvy when it comes to how relays work, but if I understand it correctly, I need a relay that will accept the 15mW input to connect the circut, and then I just steal a 12v connection from the battery to actually power the globe.

Thoughts? Or am I overthinking this...

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Unless you use a minature relay with very low power consumption
ie 20 milli amps it probably won't work either and don't forget to use a surpression
diode if you do.

I would mod the switch, if it is an oem type replacement you maybe be able
to simply remove the globe holder by turning it and replace the globe
with a led.

Leigh

[demomanca Junior Member Find all posts View Profile Close demomanca]

Unless you use a minature relay with very low power consumption
ie 20 milli amps it probably won't work either and don't forget to use a surpression
diode if you do.

Yeah, that's what I thought. I'll see if I can pull apart the switch tonight without wrecking it. Thanks Leigh (ps, got my diode from you in the mail yesterday too, thanks!)

[Cityslicker Junior Member Find all posts View Profile Close Cityslicker]

There is one issue you may find with the voltage indication. The spread is from 10.1 to 12.6V. This is quite wide for a lead acid where the "never go below 20% State of charge" voltage is about 11.6V or higher (no load - depending on battery type), which is the first yellow light on the way down.

[demomanca Junior Member Find all posts View Profile Close demomanca]

There is one issue you may find with the voltage indication. The spread is from 10.1 to 12.6V. This is quite wide for a lead acid where the "never go below 20% State of charge" voltage is about 11.6V or higher (no load - depending on battery type), which is the first yellow light on the way down.

Yeah, I figured as much. The voltage indictor only showed 2 bars less after running my engel for a weekend anyway. I'd assume that if I see the indicator at less than 3 I'll kick the car over and charge it anyway.

[Madkore Avid PP Poster! Find all posts View Profile Close Madkore]

I like the look of that voltmeter demonanca, as I am a pictures kinda guy.

How are you finding it a couple of months on?

[demomanca Junior Member Find all posts View Profile Close demomanca]

Not too bad. As mentioned earlier, realistically the battery is almost flat when it's dropped the first 4 lights, but it works well and lets me quickly see if i need to go for a drive to charge it up or not. I prefer it to a larger, more prominent gauge.

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