dual 24v solution

[Tezza]

Hi there, I'm packing a 1989 Toyota Landcruiser HJ61 which I imported from Japan. It came wired up with 24v using 2x 12v batteries in series.

I would like to know if you can get good quality 24v batteries which would occupy the same space as a regular 12v battery. Then it would presumably be simple to replace the 2x 12v jobs with 2x 24v ones and whack an isolator in there (is it that easy?). Obviously this gives me ye olde "accessories" circuit for ye olde fridge, inverter (for lappy), extra ciggy sockets and wot not.

Currently I have a 24v/230vAC inverter plus a 24v/13.8v DC converter which runs off the "main" power supply via the in-built 24v ciggy socket. Unless I'm careful to yank the main 24v ciggy plug out when not in use, it's prabably a flat battery waiting to happen (not good when nobody around can jump your 24v beast).

any suggestions, ideas, comments appreciated.

ps. I know stuff-all about electronics but I am always willing to learn if need be for any given challenge.

[BLU-125]

No, 24v batteries aren't available for automotive use.

[gidget]

is it possible to convert to 12 volt?

glow plugs,alternator, bulbs for lights & blinkers.
what else would be involved.

[evil_hitman]

radio, dash instrumentation, fuel tank sender units if they are 24 v
i think they use 2 batts so they can tap off the centre and provide 12 volt where needed.

tapping off the 12volt supply from one battery is a bad idea it kills the second battery very quickly. The only good way to do it is the way tezza already has, thats with a voltage reducer which supplies 13.8v output which is a steady supply especially important as he uses it for charging a laptop! Another reason its a bad idea to take 12v off one battery is becauase of voltage flucuations which can destroy sensitive equiptment such as laptops ;)

[Tezza]

OK, so if I want a dual setup like my 12v brethren, then I need to have no less that 4 batteries???

That is, if I want the auxilliary power supply (2x 12v in this case???) to double as an engine starting backup. Then I hang my converter/inverter parafanalia of the aux.

That's a lot of batteries :/

Even though I will get a new stereo anyway, I'm reluctant to convert everything on the truck back to 12v cos I'm bound to run into a problem I never thought of or miss something that doesn't manifest the problem until later or something.

just a bit more info for ya mate... i have fitted a rotronics unit i think(im an auto elec) to a 24 volt mitsubishi truck about 3 yrs ago. It was a 12 volt battery charger that was powered by 24 volt, therefore draining both of the original 12 volt batteries equally, then you could charge a seperate 12 volter for all your accesories and just power up the charger through a solonoid connected through the ignition circuit. Anyway am happy to give you more info if you need it just message me i will try an get the part number or something for the unit. I think from memory it was about $400 but an excellent unit.

[Redfox]

Tezza go with Tuff Toy's suggestion. I've fitted a few of these 12 Volt chargers on 24 Volt trucks too, and it is the best way to go. You still end up with three batteries, but there's no other way if you want reliability. Redfox.

[Wilesy]

I had an MQ SWB which also had 24 volt. They were sold for about 6 months in Oz before they decided to drop the idea....

I have to say, that I had absolutely no trouble with my truck using 24 volt electrics, and also any 12 volt accessories in which I had fitted I just wired them up to the left hand side battery which you could do quite safely and I had no trouble at all.

I have to say, that I did a Hella headlight conversion and with 24 volt wiring the lights were really, really bright. They didn't suffer the same voltage drop as many 12 volt systems do with headlight upgrades.

I have to say, that I had absolutely no trouble with my truck using 24 volt electrics, and also any 12 volt accessories in which I had fitted I just wired them up to the left hand side battery which you could do quite safely and I had no trouble at all.




You can do it if are strapped for cash and have no other way of doing it, but it is a very bad idea.. It does kill the second battery much quicker, if there both fitted brand new one would die within a few years as i have seen it plenty of times. This happens as the current gets supplied to the battery with the 12volt feed coming off it and the other battery never gets a correct charge into it. Very common when guys fit a CB to their truck and just take it off one battery.

[Wilesy]

Yeah,

Everyone told me the same thing at the time, though I had the truck for 5 years, and did over 300,000 klm's on it and I only changed the batteries once in that time.

sumtimes you can be lucky! although tezzas query didnt really relate to taking a 12v feed off one battery i was just making a comment about how tezza had done it the right way by using a voltage reducer and not just taking power from one battery for his 12v accesories. The reason i suggested to use the 12volt charger to charge up a seperate battery for his accesories is as that was his question, how to hook up his 12volt stuff without running the risk of flattening his starting batteries. Hence my suggestion of the third battery and a charger, which is the only viable option if he is to keep his cruiser on 24volts

[Tezza]

sumtimes you can be lucky! although tezzas query didnt really relate to taking a 12v feed off one battery i was just making a comment about how tezza had done it the right way by using a voltage reducer and not just taking power from one battery for his 12v accesories. The reason i suggested to use the 12volt charger to charge up a seperate battery for his accesories is as that was his question, how to hook up his 12volt stuff without running the risk of flattening his starting batteries. Hence my suggestion of the third battery and a charger, which is the only viable option if he is to keep his cruiser on 24volts


Indeed. This is one of the best suggestions I have heard on the topic thus far.

I had another person suggest I should buy 4 optima style batteries ("ka-ching!" $$$$). Partly because they are so small and I could mount 2 in each of the existing bays. Another reason is I already have the 24to13.8 converter and the inverter is designed to run off 24v. The main advantage of this setup is I can use the auxiliary set to start the motor if need be. This suggestion would be ideal depending on the price - I didn't realise pricing information would be so hard to come by.

I went to optima's website to do some preliminary research and duduced that the main pair would be red-tops and the aux pair would be yellow-tops (which are deep cycle but have enough cranking power to start motors without getting damaged). Cirtainly the products look impressive if the propaganda is true.
http://www.optimabatteries.com.au/

If they are too expensive, I'll go with tuf-toy's idea.

[Tezza]

Very common when guys fit a CB to their truck and just take it off one battery.


I found these earlier in the piece. Figured I'd use them when I get a new stereo and CB.

http://www1.jaycar.com.au/productView.asp?ID=AA0266&CATID

24-12V 3A Converter Module M038
$27 a pop.

yeah perfect for running CB etc! cant go wrong for that price hey mate ;D