View Full Version : 24v to 12v
101RRS
26th April 2008, 08:27 PM
Is there any one who still has the 24v system in their truck who has taken off 12v from one of the batteries and has a battery equilizer fitted. Where did you get it and how much.
I have been quoted around $400 for a redac one which I find rediculous. Similar price for a 24v-12v battery charger to charge a 12v battery from the 24v system. I can use 24v-12v converters but these are not really practical.
I currently have a 12v alternator in addition to the 24v system that charges extra batteries. I would like to remove this system to reduce the number of batteries and to free up the spot on the engine for other things later on. On this can you get a 3.5 V8 water pump/fan pully that has two pullies - mine only has one?
Thanks
Garry
muddy
26th April 2008, 08:35 PM
Garry
I spoke to cooee at cooma about this as he was having problems with his fridge .Suggested an 24/12 volt inverter (price will be relevant to size --load/current) or changing to 12volt starter and alternator . I have since spoke to him and he has made his truck all 12 volts. Give him a call.I would check what the pully system is for the ones that run air con units.
Maurice
muddy
26th April 2008, 08:40 PM
Garry
check on the pully system on 3.5 v8 with air con
Maurice
rovercare
26th April 2008, 08:40 PM
A few jap vehicles I've worked on, namely MK/MQ SD33's all have an convertor 24/12v for such duties, its not ideal to steal from one battery only on a 2x12v series cct
101RRS
26th April 2008, 08:58 PM
Thanks Muddy - Cooee and I have spoken a bit - it was he who suggested the battery equaliser but as you said he has now fully converted to 12v.
Rovercare - you are right about taking power from one battery - was hoping a battery equaliser was cheap to get around this problem - was shocked at the cost.
Garry
rovercare
26th April 2008, 08:59 PM
Jap wreckers would be the go;)
muddy
26th April 2008, 09:20 PM
Garry
I tried this at work with a 24volt system (24volt charger)running both 12 and 24 volt components. The biggest problem was trying to balance the charge going into each individual battery ,so the most effective way was to run 12 volts from an inverter and never had any more problems with battery load charging.
Garry I thing the most efficient way is to change the whole truck to 12 volt Thats if you dont run 24 volt radio gear etc. All you need to do is to change 24 volt components to 12 volt (easily available new /second hand ) and heaven forbids you need a jump start 12 volts is easy to get compared to 24 volt.
rovercare
26th April 2008, 09:24 PM
Garry I thing the most efficient way is to change the whole truck to 12 volt .
^^^^:)
101RRS
26th April 2008, 09:39 PM
Garry I thing the most efficient way is to change the whole truck to 12 volt
I have spoken to a few 101 owners about this - if the car is pulled apart like Cooee's was, not such an issue but is not just a simple matter of swapping bits.
If there is no easy way I will just stay with what I have - a seperate alternator with 2 batteries as starters (2x12v in series) and 2x12v in parallel for 12v requirements.
Was just hoping someone with a 24v system was using an battery equaliser and could advise how well it worked.
I will investigate as Rovercare has suggested to see if any jap vehicles have this system. Also I have heard that a 24v 101 does have a 12v system as well that runs off the shunt box, but I cannot find anything about it.
Garry
muddy
26th April 2008, 09:53 PM
Garry
Do you have an electrical schematic and If so could I have a copy
101 Ron
26th April 2008, 10:32 PM
Garry alot of Jap trucks run 24 volts.
A common use of them is for 12 volt trailer hook up and radio gear.
24 to 12 invertors are the go and are resonable in price .
Most of the people with respect dont know the complex nature of the 101s wiring system and the add on problems like the suspression system.
I would leave it 24 volts and use a 12 volt inverter to run what you need to run.
The distributor is running through a 24 to 12 volt resistor standard so getting rid of the complex points dist to a electronic one should not be a problem if it is still fitted.
My 101 was converted and the owner of the time fitted new VDO guages etc to over come the voltage problem with the guages and this has caused many problems in its self.
My wipers are slow.....I dont know if the wiper motor is still 24 or 12 as is the heater fan.
The original water proof altenator and equiptment is well made and I feel shouldnt be disturbed.
Go only 12 volt where you have to and go to the trouble to understand the 24volt system which most people dont do .
It is well made.
Remember 12volts requires a starter motor change too.
I would be interested how cooee changed his 101.
I am currently looking into refitting the water proof 24volt dist and high tension leads with a electronic conversion in the dist to replace the twin points,so the motor will not drown in deep river crossings.
Garry I have a very well made battery box to fit on the LHS of the chassis just infront of the rear wheel.
It bolts straight on and will take a 750 cca battery.....looks good too.
You are welcome to it ....PM me.
My 101 had only one battery in the battery box and the second battery in the chassis box (all 12 volt ) when it got it.
I since fitted to smaller batteries inthe battery box like the standard 24 volt lay out and fitted a alloy tool box for my winching gear in its place to a similar design.
Go to my photo bucket and look at my early photos you may see it.
The other thing which may interest you is or my 12 volt twin battery system is the simple and cheap switching of the batteries........done by two 12 dollar battery switches which are out of sight behind the passenger seat ,but still with in easy reach.
001-2.jpg - Image - Photobucket - Video and Image Hosting (http://s131.photobucket.com/albums/p299/101Ron/?action=view¤t=001-2.jpg)
JDNSW
27th April 2008, 05:52 AM
I agree with Ron. Leave it 24v and fit one or more converters to provide 12v where you need it.
Some examples from Jaycar's catalogue:-
MP-3061 10A $59.95
MP-3063 20A $99.00
MP-3066 40A $149.95
These are all specifically sold for use in "truck or bus", and at these prices, why would you go any other way? There are also smaller ones as cheap as around $20 suitable for low current devices.
John
101RRS
27th April 2008, 10:04 AM
Thanks everyone for your views and comments - I am aware of the options - but back to my actual query - is anyone taking 12v from one of the batteries that make up the 24v starting pack and using a battery equaliser to ensure the charge in the starting batteries remains balanced. The redarc model is about $400 - are there cheaper versions or ndo I need to go to the truck wreckers to try and find one as has been suggested.
Cheers
Garry
101RRS
27th April 2008, 11:14 AM
Garry
Do you have an electrical schematic and If so could I have a copy
See attached - thats the best I can do given the AULRO file size limits.
Blknight.aus
27th April 2008, 12:28 PM
providing your not going to go over about 70% of the rate of the converter for your planned load (no spotties or fridges) one of the 24/12v inverters is going to do the trick if your just running the donk a 10 amper is fine but you cant drag the lights off of it (parkers is a maybe)
doing the 12v side off of a single tap and equaliser was the problem the big yellow FC was having at cooma their setup was letting the fridge draw enough to unbalance the 24v batteries too far and then one wasnt charging which was the one they were drawing 12v from for charging 12v and running the engine side of business which of course all went pear shaped.
if your going to do it fit an accurate volt 12v volts gauge to both batteries in the 24v system so that you can monitor the individual voltages incase something goes wrong.
weeds
27th April 2008, 01:41 PM
yep go the 24 - 12 step down
i got one from dick smith and installed in my army car that i use part time
now i can run the engel longer and it saves killing the battery that the 12V outlets draws from
Blknight.aus
27th April 2008, 01:59 PM
Theres a bunch of these on a stall at the markets they are only between 30 and $70 for 5-20 amp units some look very second hand but they are pretty robust generaly and the old bloke reckons they all work and from the look of some of his goods Im not getting any alarmbells ringing on him being on the shonk.
If theres any interest I can have a look for them next weekend.
101RRS
27th April 2008, 03:51 PM
Thanks guys - I already some of these - I have a source in the security industry where they are used in power systems for security cameras and have a couple of 20amp versions - I am happy how these work and may end up going this route but I an interested in hearing from anyone who has fitted a battery equaliser - I am not sure Cooee had one in his truck when he had his issues.
Cheers
Garry
muddy
27th April 2008, 08:14 PM
See attached - thats the best I can do given the AULRO file size limits.
Garry
Thanks for the schematic
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