12 volt radios in 24 volt m35a2

[tm america]

Sounds like you are gonna be drawing more than 10 amps .. You could probably still get a cheap inverter or better yet get a equalizer. But if you ever think about running winches or using the 12 volt power for camping i would use a separate 12 volt alt and another 12 volt battery.. Whatever you do don't tap off of one of the batteries. It will kill the batteries trust me i tried it .. Only to have it ruin 400 worth of batteries

 

[rolling18]

I reinlisted to go to Lewis sapoidly I will be their around March 5, 2011. Thats subject to change based on win I get my stuff thats going to be shiped on a boat from Irak. As soon as I get my stuff I can start PCS process.

I am moving to Lewis some time around March 2011. Win I get their largly depends on win I get my stuff that I am shiping in our platoon conex. As soon as I get my stuff I can start the Permint change of station process.

Looks like thears a few military truck colectors in the Lewis area.
I wish I could by more tatical vehicals but its hard win you move frome base to base. Not to menchion my wife would flip hahaha

I have 3 of those in my M109a3. Two up front, one in the back. You can find them on ebay for under $11 shipped. Works great on my GPS, Phone, 12volt cooler, inverter, etc.

These seem like a cheap and effective way to go BUT how do you figure out how to wire these things in??
where does each wire go?
arn't the instructions in Chinese???

(after reading this thread I don't want to see ANY comments about MY spelling or grammar) it's sad really...

 

[Croche]

I would if just doing an audio system use the 24 volt line then run two 12 volt devices like a stereo and an amplifier connected in series means that if each has a 12 volt drop that each would only see 12 volts.

 

[59apache]

i wouldn't do that....electronic is not a bulb, you need ohmic resistance to get the right voltage. a small 24V-12V DC converter is cheap, don't fry your stereo.

 

[Psywarrior]

agreed with Rob, for the money the converter is the way to go, besides 24 to 12v pulls off both batteries so you aren't loading one more than another. If you just wired to one battery + and - then you would get 12v also but you would only load that battery and that is not good for battery life.

I disagree. You can not pick up the positive and negative terminals off of one battery and get 12 volts. They are still in series and will give you 24 volts. What we did when I was in service is go to the negative terminal off the first battery and use that as a positive. Then go to ground as the negative. This will negate the series issue and give you 12 V at the wires. It also does not overload any battery. I would get a fuse panel from any wrecked car and wire that in for 12 V and then install whatever I wanted from the panel. Of course, 20 years ago, we didn't have the regulators and battery equalizers that are available now.

 

[tm america]

I would if just doing an audio system use the 24 volt line then run two 12 volt devices like a stereo and an amplifier connected in series means that if each has a 12 volt drop that each would only see 12 volts.

You can run two 12 volt items off 24 volts but they need to have the same resistance at all times to you will fry them quickly..If at any time you are not putting the same resistance to both of them one can reciece the full 24 volts and car radios and amps don't do good on 24 volts..You can do 12 lights in series on 24 volts with good results but not to many other things will work this way..

 

[joshs1ofakindxj]

These seem like a cheap and effective way to go BUT how do you figure out how to wire these things in??
where does each wire go?
arn't the instructions in Chinese???

(after reading this thread I don't want to see ANY comments about MY spelling or grammar) it's sad really...

If you go the website selling them here: Car Power Inverter Convert Device DC 24V to 12V DC, Car Power Converter, Car Power Adapter

You can click the image of the doohickey and when it enlarges, you can read the wiring schematic laid out on the sticker. Looks very simple. Red and black to batteries (with blue included with red for radio memory saving) and then you have outputs on the other side.

Simple!

 

[59apache]

if you run 12V lights in series, remind: if one fail, both are dark. never do this with driving lights, this can be very dangerous.
cab markers, interieur lights - who cares about?
(but for what?24V bulbs aren't expensive.)

 

[deuceaid]

I disagree. You can not pick up the positive and negative terminals off of one battery and get 12 volts. They are still in series and will give you 24 volts. What we did when I was in service is go to the negative terminal off the first battery and use that as a positive. Then go to ground as the negative. This will negate the series issue and give you 12 V at the wires. It also does not overload any battery. I would get a fuse panel from any wrecked car and wire that in for 12 V and then install whatever I wanted from the panel. Of course, 20 years ago, we didn't have the regulators and battery equalizers that are available now.

What are You calling the "first battery",,,,the one that is grounded to the frame, or the one that has the positive lead to the starter?

 

[Stalwart]

I disagree. You can not pick up the positive and negative terminals off of one battery and get 12 volts. They are still in series and will give you 24 volts. What we did when I was in service is go to the negative terminal off the first battery and use that as a positive. Then go to ground as the negative. This will negate the series issue and give you 12 V at the wires. It also does not overload any battery. I would get a fuse panel from any wrecked car and wire that in for 12 V and then install whatever I wanted from the panel. Of course, 20 years ago, we didn't have the regulators and battery equalizers that are available now.

When you were in the service, YOU didn't have to pay for the batteries. You are correct you will get 12V if you tap only one battery, but it has a penalty. You will overcharge the battery that you don't tap and undercharge the battery that you do. This will in effect ruin BOTH batteries. When you have batteries in series, the current must go through BOTH, whether they need a charge or not.

When tapping only one battery for 12V, you tap the battery that attaches to the vehicle ground.

 

[59apache]

the second is the one that grounded to the frame. it doesn't matter if your connecting your + cable for 12V pickup to the - terminal of the first battery or to the + terminal of the second one. they're connected with heavy gauge cable together, the result is the same. you got 12V with - on the frame / body.
and unequal load on the batterys. doesn't matter with very small load.

there are load equilizers availible, but after thinking a lot about it, i have decided to make it once and make it right, 2 separated systems, 12V for accesories and 24V for starting.....

 

[59apache]

ok... Stalwart was faster,

 

[quickfarms]

Interesting