Installing new 12V stereo head unit in 24V HJ60

[jjlee]

Okay, so I've been searching high and low for possible options here, and I know that this has been discussed extensively, but because there are so many options, and I've never dealt with a 24V system before, I'm getting a little confused as to how I'm going to set up.

Please bare with me as this may get a little long winded:

I'm leaning towards a Solar Converter setup with a 24V relay to switch "off" the load balance mode when the ignition is turned off.

The PO installed a 10amp 24v-12v down-step converter near the center console for running 12V accessories inside. This seems to work well, and at first I was considering running the new head unit off this, with the constant for the stereo's presets tapped from the low side (12v) battery. Then the Solar Converter would be able to balance out the batteries when running.

After reading probably every post there is on the subject, I'm now thinking of getting rid of the old converter all together and using the Solar Converter to do both jobs:
1. Providing the 12V for accessories + stereo + possibly an alarm and 2. balancing the charge of the batteries.

My question is, if I do the second option, how would I set it up so the ignition closes the relay circuit?

I would also like to have the accessories (3-way cigarette lighter plug) on even with the ignition off.

Am I asking too much from my poor batteries with this?

 

[Garry]

The PO installed a 10amp 24v-12v down-step converter near the center console for running 12V accessories inside. This seems to work well

This is how I set mine up with the stand-by wire on the head unit wired directly to the low side battery (12v). the current draw is so low, it never upsets the balance between batteries. It's been working fine for 5 years or so with no worries

 

[Stone]

JJLEE: If you're wanting to be able to run the Solar Converter both in Load Balance and strict Step Down Convert modes, then you'll want to set it up like I did in this old thread: https://forum.ih8mud.com/diesel-tech-24-volts-systems/33070-solar-converter-final-setup.html I also ran the typical accessories that you mentioned plus some IPF lights and rock lights.

You don't really need to 24v-12v converter on top of the Solar Converter...but if you have it why not? I always run a separate accessories fusebox, and you usually run a relay triggered by the the ignition to turn on and off (either from original stereo harness or lighter) and run switched power through that while keeping the fusebox permanently hot.

You have to keep in mind how many amps your OEM alternator puts out...in diesels they're not very much at all. So add up all the amperage needs of the accessories you typically run at the same time and evaluate whether or not you are within the ability of your alternator. My 12H-T swap has a custom alternator that puts out 72 Amps! Good luck.

 

[jjlee]

Thanks Garry for the advice.

Stone your post is !@#&** awesome! Definitely something everyone with a 24V system should read.

I was originally thinking the same thing Garry has done and then I came across all these people who told me that I should never ever tap off the one 12V side because even the smallest draw would throw the system off balance and cause all sorts of problems.

I've slept on it and after reading Garry's reply, I still can't believe that the constant pull for just the stereo's memory and presets would be enough to cause imbalance issues. This is probably the only instance in the vehicle i would be using the one side because as mentioned before I'm already running a converter for all other accessories, including power for the head unit.

Although I do really like the efficiency and functions of the Solar Converter, but they are a little on the pricey side, and I'd like to be able to use the already installed converter.

I was also thinking if there's a way to wire the converter so that the 12v output from it would be permanently hot? This way the constant for the presets would be from both sides.

May sound like a stupid question, but I'm new to this whole thing and electrical work always defeats me.

 

[Stone]

JJLEE: Before you do the centre tap method, take a close look at the wire of the stereo that you are installing. The switched ignition wire is often RED, and the battery wire is often YELLOW. You will notice that most newer stereos no longer call the constant wire "memory" because that is not what it does anymore. Newer stereos draw their main power from the constant/BATTERY wire and just use the ignition wire to switch it on and off. Really makes sense if you think about it, because the main power draw will be direct from the battery and not through the vehicle's ignition system.

One way to tell is if your red wire is a smaller gauge wire than your yellow wire. If your Battery wire is thicker, then you will be drawing more current through that centre tap wire when the stereo is on, along with the memory function when the unit is off. If you have an older stereo that still draws main power through the ignition, then you may be alright using Garry's methtod.

Is the power draw from a typical newer head unit enough to throw your batteries off balance? I would guess probably in the long run...depending on the condition of your batteries.

If you wire your step down converter to be "hot" all the time, you just wire it directly to the battery bank...but that would also mean that even when you're not using it, you will be constantly drawing a little bit of current from your batteries. You may notice that your battery can run flat if you've left your truck sitting for a few days, especially in colder weather.

You can wire your converter to be constantly hot, and then run a 24V relay to be switched from your ignition. Then feed in another line from your converter to the supply of the relay, and then run a feed from the switched side of the relay to the ignition wire of your stereo harness. THis way you avoid using the centre tap method and still supply both functions to your stereo. Would a 10A converter be enough to power your stereo though? It definitely will not have room for an additional cigarette lighter to be piggybacked onto it, for sure. Good luck.

 

[jjlee]

Thanks Stone,
It sounds like you know this process inside out. I think you may be right about the converter lacking the juice I'm eventually going to need.

I just got an email from Greg at G&S and he says they no longer carry the Solar Converters. Would you know where I might be able to find one locally? (Vancouver area) or maybe even an alternative. Worst case, I'll have to contact Solar Converters directly and see if they can make one up with the LED's.

 

[Stone]

I'll PM you my phone number and give you a hand over the phone. Can you find a slightly bigger used converter locally? Sheldon or some of the JDM guys sometimes sell them because they often come in the trucks they import.

 

[ambulancechser]

www.surepower.com

go for the equalizer...hands down best way to center tap a 24v battery bank and keep your battery's maintained.

i use one (a vanner power systems model) on my m-1010 military truck...flawless 12v power for the last 4 years.
yes it can be pricey...

 

[jjlee]

Anyone know where I can get a used Solar Converter in question? I'm having a hard time sourcing a new one as G&S no longer carries them and I've contacted Solar Converter Inc. and they've informed me that they don't deal with direct orders.

Thanks.

 

[Granite Grinder]

Anyone know where I can get a used Solar Converter in question? I'm having a hard time sourcing a new one as G&S no longer carries them and I've contacted Solar Converter Inc. and they've informed me that they don't deal with direct orders.

Thanks.

Maybe try posting this request in the Coastal Cruiser Forum as well. There are a few Land Cruiser vendors (commercial & private) on that board, maybe someone parting out a truck... never know, plus it would be local. No promises, but couldn't hurt.
CA.BC- Coastal Cruisers - IH8MUD.com
Phil

 

[Stone]

I bought a Redarc Smart Start isolator for my 80 from Ebay. It came from a company based out of Autralia, and the few times that I've bought from Oz I've been satisfied with the quality of the product and their prompt service. Redarc seems to really know what they're doing in terms of equipment for expedition rigs...so I figure their Charge Equalizer would be well made also.

Here's a 20A model on Ebay...there are much larger ones, but they're more expensive and keep in mind the capability of your alternator.
Redarc BATTERY CHARGE EQUALISER 20amp (ce20) - eBay (item 230355562948 end time Aug-08-09 03:59:11 PDT)

Good luck.

 

[jjlee]

Thanks Stone,

Those Redarc Smart Start ones look pretty snazzy.

I know this may sound crazy, since I've been going back and forth so many times, but I'm now thinking of an alternative setup. Here's a link to a description of Freewheel's setup (last post on the page):

https://forum.ih8mud.com/diesel-tec...24v-12v-converter-extra-battery-question.html

Maybe I can get some feedback on this.

Thanks.

Oh and do you know what the maximum load a OEM alternator can handle (amps)?

 

[Stone]

Sounds neat...I'd have to Google the brand and model to look at specs. The price is certainly right.

What type of LC do you have? Are you going to install a small gel cell like he did, or a full size battery?

 

[jjlee]

I've got an '86 HJ60 (2H). I'm contemplating the size/type of battery as an auxiliary.

Although I'd like to use a full sized battery so as to not complicate things, I can see the benefits of a small sealed Gel battery. The main problem is where am I going to fit another full sized battery. I thought about putting it inside the passenger area or rear of the vehicle, I'm concerned with the off-gassing of the battery while it's charging.

I'm still not really sure what the purpose of the Samlex Battery Backup module is:
Samlex BBM-1225 25A Batt Backup Charger by Revolution Power

Wondering if I could just setup without the Battery Backup module Freewheel used and use my converter to charge the auxiliary bat. somehow (it puts out 13.8-14V).

 

[Stone]

This unit is used to allow any 12 VDC / 24 VDC power supply to function as a DC Uninterrupted
Power Source (UPS). This unit is a passive device and acts only as an
interface between the power supply, the battery and the DC load. As long as the power
supply is operating normally, it will supply the load as well as float charge the battery. In
case the output of the power supply fails, the battery will start feeding the load immediately
thus ensuring un-interrupted DC power to the load. The battery will start discharging.
Once the output of the power supply is resumed, the power supply will take over the
load and will also re-charge the battery at its float voltage.

After a quick read, if I understand it correctly, this unit goes in between the power converter/battery and the DC load. It's purpose is to provide uninterupted voltage, so when the power supply is working normally, the DC load draws power from that. When the power supply is not available, it will start to drain the battery...in Freewheel's case, the aux. battery. So it just monitors the charge, battery, and load...gives the load what it needs from the charge and whatever charge current is left over goes to recharge the battery.

I'm not sure if it's needed either...

I know my personal preference would be to use a charge equalizer and be able to draw as much current that I need while not damaging my battery bank. It avoids the hassle of a third battery and an extra component...but I am by no means telling anyone what to do...it's just what I would do again if I had to.

24V is kind of cool...but we live in a 12V world here in NA, and I'm sure glad that my 12H-T is converted to 12V and not the other way around.