24v vs. 12v - what are the advantages of 24 volts?

Discussion in 'Diesel Tech and 24 volts Systems' started by st1age, Mar 24, 2007.

  1. st1age

    st1age

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    Ok be gentle with me...

    What are the advantages to a 24volt BJ70?

    What are the disadvatages?

    Peter in Alberta
  2. maximBJ70

    maximBJ70

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    12Volt - very convenient. You can use all the accesories available in the aftermarket. Parts more readily accessible. easier to boost from a dead battery.

    24Volt - A significant more amount of juice for starter, lights, electrical winching, cold Canadian Winter starts.
    - aftermarket products are more difficult to source, need a dc-dc converter to run stereos, cb's, coolers, etc.
    - fortunately Toyota still has a good amount of 24v products so getting oem stuff isn't too big a deal, just can be pricey (but its good quality).
    - need a 24v source to boost from...plus more..keep 'em coming.
    - both are great and I'm happy with the 12v system and the 24v.
  3. brownbear

    brownbear Mod in Hibernation Moderator

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    24 volts use half the amps for same wattage.

    example, 100 watt lamp uses 8.3 amps in a 12 volt application

    in a 24 volt one it is 4.15 amps.

    Volts x amps = watts, or watts divide by volts equal amps

    So if you have a stock 55 amp alternator the 24 volt one can do more.

    Easier to upgrade headlights, as the harness may not need replacing for heavier duty wires....etc.
  4. kim

    kim

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    " need a 24v source to boost from."

    This isn't necessariy true. I've jumped my from a 12V battery pack connected to a single battery.

    Is there any potential to harm my system doing this?
  5. brownbear

    brownbear Mod in Hibernation Moderator

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    You can boost from a 12 volt battery.

    BUT you have to hook it up in parallel to one battery.

    So I will try to illustrate with words....

    In a 24 volt system, with 2 batteries. You first battery is negative to ground, then the positive goes to the negative in the second battery. Then the positive in the second battery provides the 24 connection to the vehicle.

    SO to boost to it, I would Hook the positive jumper cable to the positive battery post on the first battery. And the ground(negative) cable to the engine block on the dead vehicle or negative post on the first battery.


    This should assist in boosting. Since it is not perfect it only jumps up your voltage a bit, but not all the way to 24. As it would give 14 or so to the first battery and then what ever is left in the second would be the total voltage.


    In turn you can boost other people by cranking off on the first battery. Just connect the positive jumper to the positive on the first battery and the negative jumper on the negative post on the first battery. Take your meter set for volts it should read 12-14.

    Then hook this up to the dead vehicle.

    The harm it may cause is(boosting off one battery) is you drain the one battery more than the other. So when the recharge the second battery is going to get overcharged and low battery not enough. A 12 volt tap puts a lot stress on the batteries. Once the batteries get out of sync enough you have to replace both. As the batteries must be replaced in Pairs.

    But to get a boost, chances are you are dead anyhow, it will get you going. Best bet would be to get a battery charger and charge each battery independently to equal them up. But with all the post connections off.

    Now this is all theory in my head eh.... :lol: so it's worth the time it took to write. :)
  6. denis

    denis (O) toyota nut (O) SILVER Star

  7. kim

    kim

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    "SO to boost to it, I would Hook the positive jumper cable to the positive battery post on the first battery. And the ground(negative) cable to the engine block on the dead vehicle or negative post on the first battery."

    This is exactly the procedure I follow when I connect my battery pack. I spent some time thinking about it as well and spent a fair amount of time checking voltages all along the chain to make sure I wasn't fuc., er, making a mistake.

    Thanks for you time, Brownbear.
  8. brownbear

    brownbear Mod in Hibernation Moderator

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    That sounds right... This guy George has a pretty good explaination... little bit on a side note. Denis posted the link, I liked the info.. see below VV

  9. Anyone know if Toyota are still producing 24v models?
  10. brownbear

    brownbear Mod in Hibernation Moderator

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    Listening to the problems with the first battery and dual batteries issues on a 24 volt system, I would be tempted to install a single battery from an aircraft.

    The 24 volt battery I install in the plane I look after is huge and would work for years in a truck. They retail for 1600.00 canadian. So a bit of money. But if you get 10 years plus out of it, then your ahead of the game.

    If someone wants to drive to Northern BC I will give you a free used one...... Lots of power left. Just was slow starting my dual 750 hp engines :lol:
  11. kim

    kim

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    1600 bucks for ten years sounds expensive to me. 160 dollars a year can buy you 2 new batteries, every single year.

  12. Greg_B

    Greg_B

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    Let me preface this by saying opinions are like assholes...yada yada...so I'll thrown mine in the ring too...

    1st, I liked the way the st1age posed his question...a matter of advantages and disadvantages. This thread has stayed on that track for the most part.

    Much better then which is best, because as george has said...24V is better. But then again, 36V is even better yet! Remember the 6V VW's?

    I am also confused that george says his system has been nothing but trouble, but then at the very end says it has never stranded him in the bush.

    If he choose to convert his 24V vehicle to 12V (10 days work) due to his preception of the advantages of 12V...great! There are many valid points and 12V does have some advantages. It may be a worthwhile endevour for some.

    Yes, there are disadvantages to 24V. It is not a common vehicle operating voltage. Having one battery go bad will stop you from using the starter. In effect, both batteries are one. Parts can be harder to source (but in this day of a shrinking world less an issue if you are plugged in). It is best that one mind the battery system...or install a load balancer...or switch batteries from side to side every oil change. Spares on the shelf are always a good idea, when you can; Gives time to source someone who can rebuild 24V stuff. In this day of solar panels, charge controllers, deep cycle batteries and such...one best not go into the deep bush alone without some sort of backup; no matter 12V or 24V. And, one best understand the two battery system for jumps (to and from) etc. Certainly not as plug and play as a 12V system, but then if we all wanted plug and play we would not have older Landcruisers with mechanical systems.

    Again, as someone said...24V is better...there is no argument. Less pressure (amps) needed to do the work, or something like that.

    Just because in vehicle application 12V is more common then 24V does not mean that 12V is better. Remember VHS vs Betamax?

    What was the question again?

    gb
    Last edited: Mar 26, 2007
  13. Deny

    Deny

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    I have an extra plus to add on to all other assho.....er I mean opinions. All other points have been well said, but the 24 volt 8274 winch is the ultimate.
    That's all I got to say.
    Cheers,
    Deny
  14. denis

    denis (O) toyota nut (O) SILVER Star

    Somehow 12V is KISS and 24V is MIBS. As far as I'm concerned I would favor a dual KISS :D
  15. lowenbrau

    lowenbrau SILVER Star

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    I'm a 24v fan but it’s mostly out of habit. In the days of simple rigs like BJ42s there was very little by way of electrics. The batteries did the starting and winching and threw some light on things when required. 24V kicked ass for that, especially if the headlights were 24 volts. No stereo, no laptop, no cell phone charger. Just a super reliable truck.

    These days, I'm filling my rig with electronics, Satellite radio, GPS, computer, DVD player, fridge/freezer, auxiliary lighting everywhere, Webasto, extra heater fan etc etc etc. I'm having to design a completely separate power system for the accessories. It surely would have been much easier for me to have started with a 12V truck.
  16. brownbear

    brownbear Mod in Hibernation Moderator

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    If I was to have a 24 volt vehicle.....IMOP.. cause I too like electric goodies. I would install a second alternator, A big ass 12 volt one. Make an independent busbar for it. Use a deep cycle battery(as it is not there for starting, just play) And I would use a two wire system. No ground to chassis, ground to battery. I would not even let the electrons go to ground, only the negative side.

    Remember electrons actually flow negative to positive. Conventional theory is just for simple understanding, and cause all the diagrams are written that way.

    I even have thought of installing a 3rd battery to my 12 volt cruiser. It would charge on demand thru a solar charger, when I flicked the switch.

    Then at night I could run light, dvd's for kids, music and more. With out the fear of not starting. When the battery was dead it is bedtime.
  17. kim

    kim

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    I like it!

    I've considered the same thing but I never considered your wiring idea and saving all the juice.
  18. Lantec

    Lantec

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    That idea sounds awesome! Imagine the possibilities!!
  19. Deny

    Deny

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    Location:
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    I run the 3 battery system in my BJ42. 24v everything, then through a converter to a 12V gell battery in back which is isolated, and I can run my radio, axiliary lights till they die when camping, then start up in the morning with no problems. When I get my 12 volt truck running, will do the same thing, minus the converter, and will run a wabasto off the isolated battery too.
    Cheers,
    Deny
  20. brownbear

    brownbear Mod in Hibernation Moderator

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    That sounds good deny,
    So your 24 goes thru a converter to charge the 12 volt battery? Is it a charge converter? I was thinking of using a 12 charger designed for solar panels.....kinda like this one

    http://www.canadiantire.ca/browse/p...older_id=1408474396673605&bmUID=1175027874894

    But I am not sure if this would work. I thought I could take 12 volts from the truck system, run it thru this charge controller and then it would recharge till full then stop.

    That way I would not have to isolate the batteries, and have my alternator only charging the 3rd battery. I would still though have a switch so I could turn this on when I wanted.

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