Bottom Line...24v to 12v

[GregS]

O.K. guys, I've read most of the posts regarding this subject and have gained some useful knowledge. Thanks to all. With that said, maybe some of you with more experience and know-how than I with vehicle electrionics can advise me. I've got a 1982 BJ42 3b 24v all original cruiser that I will be installing a stereo system in. I need a clean (constant for memory functions) 12v source of power for the stereo and amp and will also be wiring my existing cigarette lighter to 12v for charging a cell phone (I've purchased the 12v lighter to replace the existing 24v). I would like to avoid any of the unbalanced draw down issues between batteries. It's got two brand new batteries installed. My typical tendancy is to over build. Assuming that I keep this truck in it's original trim (I will) and not turning her into a trail only rig with multiple power hungry draws, what's my cleanest most efficient option(s)?

[Greg_B]

Originally Posted by GregS

O.K. guys, I've read most of the posts regarding this subject and have gained some useful knowledge. Thanks to all. With that said, maybe some of you with more experience and know-how than I with vehicle electrionics can advise me. I've got a 1982 BJ42 3b 24v all original cruiser that I will be installing a stereo system in. I need a clean (constant for memory functions) 12v source of power for the stereo and amp and will also be wiring my existing cigarette lighter to 12v for charging a cell phone (I've purchased the 12v lighter to replace the existing 24v). I would like to avoid any of the unbalanced draw down issues between batteries. It's got two brand new batteries installed. My typical tendancy is to over build. Assuming that I keep this truck in it's original trim (I will) and not turning her into a trail only rig with multiple power hungry draws, what's my cleanest most efficient option(s)?

Pimp mode? Use a Solar Converter for clean efficient power, 24V-12V stepdown. IMO, one of the better ones out there. If you want to load balance when running, or turn on/off the load balance then check this thread: http://forum.ih8mud.com/diesel-tech-24-volts-systems/33070-solar-converter-final-setup.html

Out of pimp mode now...

The BEST way to get 12V is to run a seperate alternator, to an isolated deep cycle battery, and take all your 12V needs off that. In reality, this is not easy for many, and not an easy install, otherwise you would see it all the time.

The 2nd BEST way is to use an isolated deep cylce 3rd battery, fed from a step down converter. Have the fed going from the converter on a HD relay which is hooked to a monitor, so it shuts off when your starting batteries get too low. Or, simply hook up the feed from the converter through an ignition powered relay. Take all your 12V needs off the deep cycle battery, and Bob's your uncle.

The 3rd best way is to run a load balancer 24V-12V converter which feds through to a fuse strip for your 12V needs, wire your memory and constant 12V need supply needs straight up, and relay anything you want ignition switched. Then....tap into the 12V feed line in the engine bay through a HD switch as Stone has done, or a HD relay has I have done...to go in and out of load balance.

The 4th best way, and some might say the 1st best way if your 12V needs are minor (below 20amps) is to run whatever converter you get in strict 24V-12V convert mode, to a fuse strip. Then relay whater needs to be ignition power, and run the other needs hot all the time.

hth's

gb

[GregS]

Thanks Greg for the options. Lots to think about. I like Best and Second Best choices for the sh.. hottest way of doing it, but will probably opt for a switched solar converter for my rookie attempt. How hard would it be to wire the LED indicator lights into the cab for monitoring? Would it make sense to also place the HD switch in there as well?

Thanks..GregS

[motorcoach123]

Hi Guys
I'm just a new newbie here but have worked with 24v systems for years. I think a Vanner style battery equalizer is a viable option that would keep the two existing batteries balanced, and also give you 12v on your BJ for stereo or whatever. Most all tour buses in North America use this style of system to keep balance between the two batteries on their 24v system, as well as giving them 12v of power (good for anywhere from 35 to 70 amps depending on size of equalizer unit).
Cheers,

[Gold Boy]

Originally Posted by motorcoach123

Hi Guys
I'm just a new newbie here but have worked with 24v systems for years. I think a Vanner style battery equalizer is a viable option that would keep the two existing batteries balanced, and also give you 12v on your BJ for stereo or whatever. Most all tour buses in North America use this style of system to keep balance between the two batteries on their 24v system, as well as giving them 12v of power (good for anywhere from 35 to 70 amps depending on size of equalizer unit).
Cheers,

Thanks for post..interesting...

How much $'s for the vanner equlizer unit...


GB

[Stone]

Interesting...

(courtesy of Google) http://www.vanner.com/htm/pro_01.htm...51112&a=a&pt=3

Wonder what it costs compared to the Solar Converter? Same idea...

[GregS]

Thanks to all for the replies...I've got an inquiry into a local (Oakland, CA.) supplier of Vanner equipment. I'll post the reply when I get it.

Stone,
I know if it were a snake, it would have bit me, but where should I be looking for the repost of the info on your 24v/12v conversion? Sorry for my general stupidity...Greg

[Stone]

Originally Posted by GregS

Stone,
I know if it were a snake, it would have bit me, but where should I be looking for the repost of the info on your 24v/12v conversion? Sorry for my general stupidity...Greg

Hey Greg:

No need to be so harsh on yourself. On top of the listing of threads in this forum, you will find an FAQ. Click on that thread and you will find links to most of these questions...including the discussion of my Solar Converter setup with the photos in it.

http://forum.ih8mud.com/showthread.php?t=33070



Stone

[GregS]

Thanks Stone...I got it. Learn something new everyday.
Greg

[Greg_B]

Originally Posted by GregS

Thanks Stone...I got it. Learn something new everyday.
Greg

GregS, in addition to seeing cost and install features, check with the retailer and see if the "drawing down the good to support the bad" syndrome is prevelent when systems sit a while...with the Vanner in load balance too. You may get the pat "never had a problem" but with something that is run every day it is typically not an issue at all, unless you are in -30 or -40 weather and stressing the batteries to the max.

Also keep in mind that the stock 24V Toyota Alternator is 30amp (some are as low as 25A and most are 30A). I tell people to consider worse case senerio (middle of winter, heater on high, wipers on high, headlights on (and maybe driving lights if you have them). Now figure out how much excess 24V amps you have. Probably not a lot. One needs to keep in mind the total load on the alternator, or you will burn it out. This is another nice reason to run the isolated deep cycle 3rd battery...

For most people that want to run a standard stereo, alarm and charge a cell phone this is not a concern.

Post it up when you find out!

Thanks

gb

[ivanhoe]

Originally Posted by Stone

Interesting...

(courtesy of Google) http://www.vanner.com/htm/pro_01.htm...51112&a=a&pt=3

Wonder what it costs compared to the Solar Converter? Same idea...

just got off the phone with a québec distributor, the prices are as follows;

60-10B (12v-10a)= $390cdn
60-20A (12v-20a)= $492cdn
65-60 (12v-60a)= $636cdn
1yr warranty
hth,
ivanhoe

[Stone]

Originally Posted by ivanhoe

just got off the phone with a québec distributor, the prices are as follows;

60-10B (12v-10a)= $390cdn
60-20A (12v-20a)= $492cdn
65-60 (12v-60a)= $636cdn
1yr warranty
hth,
ivanhoe

WOW! Makes the Solar Converter a heck of a good value. Been 3 years for my Solar Converter...still have the same batteries that I bought for my inspection, and the voltage readings off of them haven't changed one bit.

Thanks for the research info Ivanhoe.

[ivanhoe]

i don't know the rated amperage for the solar converter's but the vanner's are somewhat beefy IMHO! you can also get 80A & 100A units but you're gonna need a welder as a alternator, lol!
ivanhoe

[Stone]

Solar Converter puts out 12V @ 20A.

[Greg_B]

Originally Posted by Stone

Solar Converter puts out 12V @ 20A.

Yes, for the model I most recommend for the reasons listed above (overloading the alt). 96% efficiency. Solar does make a 40amp model. Takes a lot more space, and is just a tad cheaper then the Vanner 20amp model.

The Vanners certainly appears very industrial...no doubt. Little use going to anything above 20amps at 12V imo, unless you are going to run a 3rd deep cycle battery, have major draws, and make sure you have NO other load on the alternator when using those draws. Start adding up the costs...makes sense to me to maintain as much 24V as possible to make use of the efficiency. Or if you are going to spend that kind of money start looking to an electric vacuum pump, and source out a high output 24V alt. I've never looked into availablity though.

ivanhoe, the 60 amp model is going to use every available amp from the stock alternator...and probably a little bit more.

They certainly do appear...nice...thought.

gb

[Stone]

I wouldn't recommend going above a 20A model either, for the exact reasons GregB has already mentioned.