Alternator

[rodw]

Just an update, the OzCharge took about 5 hours to get to fully charged and that was after 3-4 hours driving yesterday. With the charger connected in maintenance mode, the UHF showed 13.4 volts and it dropped back to 13.2 volts when disconnected. A long time since I have seen the voltage over 13 volts. Once the battery was fully charged and it entered the float/maintenance mode, the fan turned off. I guess that because the fan turns off when fully charged, they would not be too bad in a powered caravan site situation. The noise from the fan could be a concern. I am going to try the rejuvenation setting tonight that does the desulfation thing.

[Squid_87]

Rod, was this connected to your main battery which then trickle charged your aux?

[rodw]

No mate I hooked it straight to the AUX battery so the Cranking battery would not have got a charge. I have not bothered charging the cranking battery yet. I guess you'd need to disconnect the AUX or you would end up charging both batteries together (which would not be a drama with a 16 amp charger), I'll give it a try to see if the isolator kicks in when charging the main battery.

I have put the charger out on the car again tonight on the rejuvenate setting. That does not appear to be charging, just doing the desulphation thing...

[bansheebuzz]

what sort of dual battery system to do have rod, if ist a smart solenoid like a redarc then it will try charge both batteries if you hook it up to the main battery

[rodw]

what sort of dual battery system to do have rod, if its a smart solenoid like a redarc then it will try charge both batteries if you hook it up to the main battery

That's what I figured. I have got an ARB isolator so it will do the same thing. I am not really concerned too much about charging the cranking battery but will give it a go with both batteries tonight. The rejuvenation setting added an extra 0.2 volts overnight.

[Twiggo]

Thanks for the info to all, in particular Rodw and Olcoolone. It's only taken a month to see how my thread went and I see i'm not the only one wondering. The car is running an ARB system and the aux battery holds charge perfect when charged from the mains overnight, also the third battery that was in it was taken out as I doubted its well being (it and the ARB Exide struggled to hold 12.1 V when together in the hilux) and put it in my WRX when it dumped its battery and the indicator went green for the first time without help and its been perfect for 6 months even with car audio abuse. I think the charging system is OK as the start battery never goes flat. When driving usually 2 DeWalt chargers @7A 12V DC each are in use and sometimes a 120 L Waeco in summer. From the invertor we run all sorts of things and usually use it with a 120 Ahr SLA batt as well.the 120 only goes into the car when we know we are working without power for the day. Voltage when the car has been running for a few minutes is usually about 12.7-12.9 but once aux ARB battery has been run down and tried to charge from the car it drops to 10.9-12.1 as soon as motor is switched off (will sit at 12.6 after mains chrger turned off). So armed with a bit more information, do you guys recommend going for a bigger alt as well or just a DC-DC cahrger, and is it true that if you have 2 Aux batteries that they should be the same type as the third lives where the air cleaner in the diesal goes and I am limited for size there. Also would a 30A charger be enough as I figure that the existing alt probably cant spare much more.

[KClux]

Hi Guys just been reading through this thread, great stuff. Correct me if I'm wrong but with all these accessories that are being run surely the alternator would not be able to take it and burn out. For example a powerful speaker system + fridge + both accessory and driving lights etc etc all equate to a lot of amps being used easily more than the 100ah the alternator can supply. therefore this will slowly weaken the batteries and they will not charge efficiently. I believe this is the same problem Twiggo is having so i would personally suggest a bigger alternator myself, the DC to DC charger is no real fix, a bigger alternator would keep up with the power requirements u use and stop ur current one from being overloaded, though i am happy to stand corrected.

[rodw]

Hi Guys just been reading through this thread, great stuff. Correct me if I'm wrong but with all these accessories that are being run surely the alternator would not be able to take it and burn out. For example a powerful speaker system + fridge + both accessory and driving lights etc etc all equate to a lot of amps being used easily more than the 100ah the alternator can supply. therefore this will slowly weaken the batteries and they will not charge efficiently. I believe this is the same problem Twiggo is having so i would personally suggest a bigger alternator myself, the DC to DC charger is no real fix, a bigger alternator would keep up with the power requirements u use and stop ur current one from being overloaded, though i am happy to stand corrected.

I think for most of us the stock alternator will do. 2 x 100 W spotties = 16 amps, my Amp only needs a 20 amp fuse so it is similar and the car PC similar again, the fridge draws about 4 amps max (average 2 amps) and CB is about 2 amps. So maximum draw will be about 50 amps at night plus whatever the engine stock wiring draws 20-30 amps. In twiggo's case, his load is fairly extreme and he must know that, the DC charger will probably help out but I'd probably think he needs a second alternator to fix it properly (if he can squeeze one in)....

[KClux]

I think ur right Rod for most people that would be the case. Surely the alternator cannot run at 100% to keep up with all your power requirements, just judging from what you've said thats about 80ah possibly more if ur including driving lights or is that in your engine stock wiring calculation? either way its a lot of load going on. i would say u would definitely need a bigger or second alternator and that a lot of us don't realise how close we are to needing more power as well with 5 million accessories throughout the car. I no have heaps.

[rodw]

Remember though, you don't drive with your spotties on all day, My car has enough capacity to charge batteries now so I am not worried and I top up with the Oz Charge charger when required overnight. But this is more to make sure the AUX battery is 100% charged before I need to depend on the fridge.

Years ago, I drove a Mini (my first car) and when I turned the spotties on the amp meter showed I was discharging which was interesting over a 600 km night drive I did quite a few times... Might have been a small car but it had a full sized battery whihc was fortunate.

[olcoolone]

Even if you fitted a bigger alternator you still will not be able to charge your battery's beyond about 60 - 70% SOC.

So it would still pay to fit a DC-DC charger.

Rod you are right most people don't drive much at night on high beam with driving lights on and most people don't have killa sound systems that draw big amps.

Nearly all cars have around 100 amp alternators, there is no need to go bigger for the majority of people and to go bigger means to go bigger in size as well.

The down side is the bigger the output the dirty the output signal gets, the heavier the alternator is, the extra HP to drive it no to mention the room needed to fit it and the HP capabilities of the belt drive.

Years ago in some Jap alternators you could change the winding configeration to increase output but not now.

Don't forget your alternator is 3 phase.

[KClux]

Your right, i was just stating the worst possible combination, if you were listening to loud music driving at night spotties on on country roads with your fridge in the back etc etc then you would have problems. Your definitely right tho most people would not hit these kind of issues as 100ah is quite significant. another way to solve it is with gel batteries (i personally have these, got mine for free so cost is no issue) these can charge above that 60%-70% benchmark which gives you that little bit more. Of course the best thing is to just not run so much and save as much power as possible to have more equipment.

You could get a solar panel that will top up the batteries as well during the day, but that of course costs money and space. Good luck finding a solution tho

[Twiggo]

Whilst my loads are heavy sometimes, my work varies from week to week and sometimes I just need to charge a couple of drill batteries whilst driving. With no spotties & stock tunes, I will start with a DC-DC charger and see how I go. If the alternator dies then I will be forced to replace it. My old falcon hearse had a smaller alt (55A) and the battery seemed to last longer, whch leads me to think that the brains are stopping the brawn. Once the cahrger is in I will give an update. Still need to replace the 2nd AUX batt, does anyone know if it should be the same as the other?

[olcoolone]

Kclux, why can a gel battery charge above 70% in a Hilux?

[bansheebuzz]

just got info on redarcs new smart charge system 12v-12v charger

rated at 20amp max current
selectable profile for agm, gel, calcium and lead b atteries
sealed unit so can be mounted in the engine bay

[KClux]

olcoolone, basically these type of batteries charge more rapidly and from a lower voltage than normal deep cycle batteries. They are more likely to fully charge after a good drive and will at least charge faster and deeper than traditional batteries. They are heavier and a lot more expensive, but they do attain closer to full charge. not 100% sure on the chemistry why, but i no this is the case as i have read up on them. A DC-DC charger will actually help also attaining closer to 100% charge so both would be the best option. I take back what i said about DC-DC chargers earlier, it will help the charging process i just checked up about them. It will charge the aux and main battery in their optimum ways so that they can get as high a charge as possible. The alternator however will still limit the system and how fast and how high it charges.

hope this helps.

[olcoolone]

Kclux, what brand and model are these battery's.

[KClux]

Panasonic
Model No.LC-XC1238P

its a 40ah worth $250 ea

i hooked up a couple for the extra power.

[olcoolone]

Don't know where you got your information from but that battery requires 14.5 to 14.9 volts to charge.

Here are the specs http://www.actec.dk/Panasonic/pdf/LC-XC1238P.pdf

Hate to tell you but they are nothing special regarding charging or capacity...just a good brand name and high quality and overly expensive.

There are just the same for charging as any other AGM or deep cycle battery.

Your Hilux will charge it to about 600% SOC and a DC-Dc charger will help you heaps.

[KClux]

thats strange, I read in a 4WD camping magazine article that gel type batteries can charge from deeper. the same article said that a dc to dc charger would help to get it right up there, which is why i retracted my earlier statement when i went back through the article. i quoted pretty much straight from the article and as far as i know it seemed to be right. how would u explain this? . any info on why this is all the case tho would explain a few things to me tho. i got them free so the price wasn't really much of an issue to me.