Dual battery question
- Thread starter V9x
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I really should read my manual , I might learn something lol I thought the Vdc switched off in 4wd , but clearly that's not the case . I'm glad I can buy individual bash plates , I will investigate getting some more for my vehicle . It looked to me like there was a few places that the plates could mount onto
Ah that's what it means . BTW Just purchased optima 34c yellow top and c tek dc to dc charger today, cable and fittings. Just need to fab up a battery tray to mount under the tray. Also got someone coming around to fit my new DVD head unit and reverse camera and UHF radio. Exciting : ) will post pics when done
After much discussion with the seller , I was assured it will work. The way it gets around the problem apparently is by wiring it up a certain way. If you wire from the alternator to the solar input on the ctek it will compensate for the lack of voltage. At least that's what I was told . Because the solar input is configured for low voltage it is compatible with smart alternators .if it doesn't work I'll take it back to battery world down the road. I hope it works : ) does that sound like a reasonable explanation ? If its not going to work I'll take it back before I mount it.
-Shay-
Member
Ctek have released a new product to compensate for new alternators being a pain in the arse, a 30amp relay.
http://www.ctekbatterychargers.com.au/ctek-d250s-dual.html
http://www.ctekbatterychargers.com.au/ctek-d250s-dual.html
That's the drawing I have . Apparently wiring it up that way ,overcomes the smart alternator problems.
Questions
1) what amp circuit breakers to run for that set up ? I have a 20 amp for the incoming to the charger , I was thinking 50amp for out going off aux battery .
2) what size cable and fuse to run for 12000 pound winch that draws 400 amps?
I'm thinking almost welding cable wire ? Then I'm not sure for the fuse/circuit breaker . I have never seen anything that big before .
Can't say I disagree with Tiger.
Welding cable is often made from aluminium (which is a better conductor than copper) but it's more brittle and in automotive applications may not last as long. That said though, it may well outlast the winch. 0Ga copper is my choice.
As for the C-Tek comment - it's hard to disagree with the dodgy call. The solar input is designed to vary and internally the C-Tek boosts the voltage so that it can have enough to charge the battery. It does limit its charge though - 12Vx25A = 300W. 300W/14V = 21A, and that's not even accounting for the losses in the C-Tek's circuit. Means it'll struggle to provide a decent charge.
I'm questioning the wisdom of having the alternator "shut down" like that. You can't be saving huge amounts of power - it'll be a small percentage of engine load, so the saving for this new technological marvel doesn't seem to balance the cost of developing it.
Welding cable is often made from aluminium (which is a better conductor than copper) but it's more brittle and in automotive applications may not last as long. That said though, it may well outlast the winch. 0Ga copper is my choice.
As for the C-Tek comment - it's hard to disagree with the dodgy call. The solar input is designed to vary and internally the C-Tek boosts the voltage so that it can have enough to charge the battery. It does limit its charge though - 12Vx25A = 300W. 300W/14V = 21A, and that's not even accounting for the losses in the C-Tek's circuit. Means it'll struggle to provide a decent charge.
I'm questioning the wisdom of having the alternator "shut down" like that. You can't be saving huge amounts of power - it'll be a small percentage of engine load, so the saving for this new technological marvel doesn't seem to balance the cost of developing it.
There is a thread on here somewhere about the alternators on the new D40's - don't hold me to this (its from memory) but the wires out of the alternator, find the green/white one and cut it. Fixes the issue instantly and keeps the voltage up constantly.
I'm running a dual ctek in my tray with 2x95AmpHr batteries and it works perfectly. All the time. Late 2011 D40.
Easier than wiring in a fuse!
I'm running a dual ctek in my tray with 2x95AmpHr batteries and it works perfectly. All the time. Late 2011 D40.
Easier than wiring in a fuse!
Did you cut the wire on the alternator on your setup? Or have you wired your ctek up with the relay into the solar input?
d40ryan
Member
i dunno what everyone is on about with the smart alternator..... must be a new navara thing. mine sitts at 14.1 all the time and the ctek with have the rear battery sitting on 13.1 (full) and then if it drops will top it up as needed. my ctek d250s is working correctly. with nothing but the unit
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From 2012 onwards, Nissan changed the alternator so that as soon as the battery reaches a certain voltage, the alternator idles - it basically turns off. This unloads the engine, probably provides an extra couple of kW and might save a tiny bit of fuel, but it will also increase the life of the alternator.
Not sure if it's worth doing if everyone's gonna cut the wire!
I am considering cutting the wire . I'm going to wire it up the way ctek recommended to start with and monitor the charge for a while. If that fails the wire will be cut lol
Ok so ive nearly finished fitting up my dual battery system and other bits and pieces to my nav, I think my c tek is working properly after checking my manual and seeing what all the lights mean on it. Was running cable last night in the dark and just started it to see but I think it's ok.
I put a voltmeter in my dash and ran the positive from the battery terminal to the meter and earthed the other end behind the dash , but it looks like I'll need to pull the cable out and run the earth back to the battery as the meter is all over the place and won't give a stable readout. I tested it on the terminals and it worked great , so the earth must be the problem. What a mission this job has been , fabricating battery trays ,running cable , crimping ,heat shrinking , now trouble shooting . I don't know how auto elecs do it! I paid a bloke to help me who did the head unit in my car , and when he seen me using conduit and heat shrink on the job , he told me it wasnt needed and I was being fussy! Mind you he wanted to run cable to my reverse camera through the grommets in the floor !! I had to remind him it's not some 18 yo kids cheap old BMW your working on here and FYI this is a 4wd and I don't won't water coming up through my floor .. Dickhead! I am fussy so it takes longer to do it my way , but I should never need to do it again : ) and my car hopefully won't catch on fire this way hahahahaha
I put a voltmeter in my dash and ran the positive from the battery terminal to the meter and earthed the other end behind the dash , but it looks like I'll need to pull the cable out and run the earth back to the battery as the meter is all over the place and won't give a stable readout. I tested it on the terminals and it worked great , so the earth must be the problem. What a mission this job has been , fabricating battery trays ,running cable , crimping ,heat shrinking , now trouble shooting . I don't know how auto elecs do it! I paid a bloke to help me who did the head unit in my car , and when he seen me using conduit and heat shrink on the job , he told me it wasnt needed and I was being fussy! Mind you he wanted to run cable to my reverse camera through the grommets in the floor !! I had to remind him it's not some 18 yo kids cheap old BMW your working on here and FYI this is a 4wd and I don't won't water coming up through my floor .. Dickhead! I am fussy so it takes longer to do it my way , but I should never need to do it again : ) and my car hopefully won't catch on fire this way hahahahaha
Job done! Finished late this afternoon and all is working fine . Ctek is pumping out good voltage, checked the voltage on the aux battery whilst charger is running and I was getting just over 15 volts and my voltmeter in the cab was reading about 14 volts in the cab. I'm guessing the difference in readout must be due to voltage drop, as I had run smaller cable 4mm for about 5 meters back to the cab for the voltmeter . Being that this is my first dual battery set up and im not 100% sure about it ,do those figures sound acceptable to you guys? Should I have put a fuse going to the voltmeter off the aux battery ? I read the current draw for the meter in the spec sheet and it said it was drawing something like 5 milliamps , so it seemed safe and pretty low voltage to me.
Cheers
Cheers
The fuse is essential, close to the battery. It doesn't protect the meter. It protects the car from a fire if the cable snags and shorts on the chassis. Even a 1A or 2A fuse would do.
1V over 5m ... sounds reasonable to me.
1V over 5m ... sounds reasonable to me.
