Redarc bcdc just failed - do they really make a difference?

Thanks for the suggestions, unfortunately the Opposite Lock branch that fitted it has closed down and their head office (Dandenong) is way to far for me to travel to when back home in Melbourne. I still have another 5 weeks of travel.

Hopefully I can find a auto elect in Broome and get it sorted. Total waste of good holiday time not to mention the warm beer and spoiled food. That's why I will probably ditch the Redarc and just get a simple isolator installed.

It's always aftermarket devices that seem to let you down, the ARB Bullbar has done another wing bracket, the Rhino rack legs started rattling, 2 BFG All Terrain Tyres with punctures however the car has not missed a beat (2014 Hilux).

Mine was fitted by ARB. I had a kaymar bar fitted later on by ARB and had to go back twice because they stuffed up the electrics. When the fuse went I went to Opposite Lock and they advised the fault in the wiring.

In your it was Opposite Lock who apparently fitted the wrong wiring.

I had mine rewired at my expense by an auto electrician. I don't want to ever take my vehicle to ARB unless I have to.

the issues you are having with the tyres, bullbar and roofrack are normal casualty of such a trip, welcome to the club

I recommend Greg Reen of Reen Auto Electrics in Broome.

I recommend Greg Reen of Reen Auto Electrics in Broome.

I agree with Bill 100% about NOT locating a DC-DC charger under the bonnet....even if the manufacturer says it's okay to do so.

I've always mounted my DC-DC chargers in the back of the rig/s, close to the aux batteries which, in turn, are close to the fridge and air compressor for which they are needed.

Following such ideals I've never had any issues with my battery set-ups over a 26 year period.

Mind you, I also have a good quality multi stage 240 volt charger mounted in my rig/s and hard-wired to the aux batteries. Whenever the truck is at home I have it plugged in to the power to keep the batteries at float stage.

My current truck (Chev Silverado) has 3 aux batteries in the back plus the 2 standard batteries under the bonnet. There's 2 solar panels on the roof of the canopy as well as a 25 amp 3 stage charger. Never have any issues with power (touch wood).

For goodness sake though........use heavy gauge wire.

Roachie

You assume all the batteries are under the bonnet...

Malcom,

Why do you say that?

Please explain.

Phil

Hi Phil
Well if the battery is somewhere in the back of the truck, he could have a decent voltage drop across the cable feeding it. The DC-DC would solve that.
I lose a volt or so between the cranker and my trailer connection and that's using 6B&S

Wouldn't it then be best to install larger cable with less loss?

Phil

My apologies.

I know what you mean and I was hoping to get people to think "outside the box". The problem is resistance in the cable to the rear. Why not use a solution that is more reliable and won't break to overcome the problem.

We did with the two fridges way down the rear of the car. I got the sparky to install large wire and now only have 0.1 Volt drop to the rear.

No devices to break down etc. Just plain old copper wire. Cost a quid but it is much more reliable.

Phil

Here is another example of how I personally overcame loss.

As a lot have realised by now I am a licenced unrestricted amateur radio operator. I am permitted to use transmit signals with a power output way in excess of the teeny 5 watts allowed on UHF CB. I wanted to increase my output above what the little amp in the radio would give me. Not being flush with hobby funds the solution was simple. I had a run of RG58 mil spec cable to the tower. I simply replaced it with low loss RG213 and doubled my effective output power. As mates in the USA said "Get youself a linea did you Phil".

Same with the car. Lower, well all cable has a loss, loss cable to the rear.

Phil

Well I'm an electronics engineer and have access to cable etc cheaply and have to agree with you theoretically but...
The cable you'd need to run to the rear of a truck would be some 50mm2 in size.
You'd need two runs of that (+ & -). Guessing some 6 meters on each leg @ around $20 per linear meter = some $240 just in copper. which weighs some 6Kg per meter = 72Kg extra weight. Rather have 72 liters of extra fuel & water.
Yes its arguably more reliable depending upon who terminated and installed it but simpler, no not really. Much easier to run a smaller cable and screw down a small box.
The only real question here is - has the Redarc actually failed or are other issues involved? Extremely reliable brand so its unlikely but if you hate Redarc then install a Ctek, also extremely reliable and well regarded.
Anything can fail. Do you carry a spare alternator?

Thanks Malcom. I never did the sums myself. No need as all batteries are close being under the bonnet. I just get amazed at the mentality of wanting to install electronics, that break at time, to overcome what may first appear as a simple solution.

Reliable but it did break for the op. Wouldn't want it to break and destroy the food when hundreds of K's from civilisation. We like the deserts and on the last drive we didn't see another car etc for five days. And we were moving every day, not just camped in an out of the way hidy-hole.

You are certainly spot on with the installation needs. I had to redo all the wiring to the bullbar. They didn't even add some protection from stones. If you want it done properly then pay or do it yourself, if you have the right skills.

Phil

Why would you need to run 50mm2, everyone seems to focus on the voltage drop.

Voltage drop only becomes a significant issue when large currents are flowing, if you have large currents flowing into a battery then the battery is low and under such circumstances high terminal voltages aren't required to get large currents flowing.

A DCDC charger will not get up to its maximum voltage unit the battery reaches around 80% -90% SOC, at which time the current will be rapidly falling.

As the battery charges the current will drop and the voltage drop across the cabling will fall, by the time the battery gets to 90% the charge rate will be falling rapidly to less than a few amps and what will the voltage drop across say 20mm2 cable be at 5A the voltage drop would be around .1V with a 10M run.

In my own setup I have a Marine pro aux in the car, two AGM's in the camper and have no problems charging them all.

If you had a three way fridge also sitting across the batteries then things would change but they would also for a 20A DCDC charger so why would you set it up that way.

Good argument but often large currents are involved.
Plenty of people have a battery in the back and run a rear winch. In reality, which battery would you think most of them wire to?
I also have a Blue Sea controller that can crowbar both batteries together should I flatten the cranker. Hell of a voltage drop there without lots of copper to the rear.

Also, consider that you have been parked up for a few days and pretty much flattened that battery in the back. You might want to charge it again as quick as poss plus charge it with the correct voltage...

I'd rather fit a DC-DC converter myself and half the cable size. Yes it might fail but in that case I will bypass it and buy a replacement at the next town.

Campers are a different argument but lets go with your example for a minute. My tug is fitted with 4 or 6 B&S (forgotten which) to the tow bar and same from there to the rear of the camper where the batteries live. Running a 80L Weico plus a few lights etc gives me a volt dropped across the cable. Effectively a 10% loss.
I run a Ctek to keep things sweet plus integrate solar into the system.

Again we get back to the fact that if large currents are flowing you don't need high terminal voltages, a Marine pro for instance will draw around 50A when discharged to 50%SOC and connected by around 6 metres of 6B&S cable to a standard alternator out putting around 14.3V. The batteries initial terminal voltage will be around 12.8V when first connected, after around an hour the current will have dropped to around 18A and the terminal voltage will be 13.7V

Total charge put back in to the battery in 1 hour 40 minutes is around 42.78A (85.5%). A 20A DCDC charger would have replaced 33.33A in the same time. (66.66%)

Your also your assuming the DCDC charger will be putting out more voltage, if your batteries are down it won't, it will be in current limiting mode and the voltage will also be low.

If you had 20mm2 to the camper batteries then the alternator will put the bulk charge back in quicker. Your fridge will be cycling on and off and your lights will most likely not be on when your travelling.

I have two runs of 6B&S cable to the camper, a 100Ah wet aux in the car and two 100Ah AGM's in the camper, if I'm camped for three or four days and run the batteries down to 30% SOC (two fridges running, heating, pumps etc) it takes around a four hour run to recharge all batteries. With a 20A charger I would only bring the campers batteries up to 70%. A 40A charger would be quicker for the camper batteries but adequate cabling would still need to installed and then I would still need another charger for the car aux or a VSR setup.

I fail to see what rear winch has to do with it, your not likely to be silly enough to run the winch via a DCDC charger or direct charge cabling for that matter?

True HKB and that's why with all the gear at the rear including fridges and compressor we only have have "0.1 Volt drop to the rear" as I said before.

But it is handy having all batteries with 2M (cable run) of each other.

Phil

Phil, what are waecoes like for parts and service?
Have a 100L waeco for arohnd 13y and only had probs on GRR, one fan died and had parts in Broome then 2003 approx didn't like dust from being in back of ute
Tks Ric