3rd Battery and Isolator

[stationjj]

Hello,

I have a stock 24 volt M1009. I am wanting to add a 3rd battery for 12 volt accessories, and HAM radios. I need some advice concerning connection.
I have created a spot for deep cycle battery. I am looking at a 200 amp Cole Hersee #48162 to be exact.

The hookup seems better simple. 1 to an alternator, 2nd to front battery 12 Volt, 3rd to 3rd Battery, 4th to a switched hot wire.

I have a few questions I am not sure about. I am no DC electrical expert. There has been a post on this subject with CUCV, but I want to verify I am understanding this correctly. http://www.steelsoldiers.com/showthread.php?122122-Battery-Isolators

Questions;

Can the current alternators help maintain a 3rd battery?
The 4th connection for the switched hot wire will be connected to a 2nd fuse panel I added with relays. So it is only charged when CUCV is running. Is this Good?
The battery insulator is 200 amps. Is this no Much? The CUCV alternators are 100amps?
Is battery equalizer a better option?

I open to suggestions Thank you for your help.

John

 

[MarcusOReallyus]

The hookup seems better simple. 1 to an alternator, 2nd to front battery 12 Volt, 3rd to 3rd Battery, 4th to a switched hot wire.

It's not clear to me what you are saying here, but rather than trying to sort that out, see more below.

I have a few questions I am not sure about. I am no DC electrical expert. There has been a post on this subject with CUCV, but I want to verify I am understanding this correctly. http://www.steelsoldiers.com/showthread.php?122122-Battery-Isolators

Odd. That link doesn't work for me.

Questions;

1. Can the current alternators help maintain a 3rd battery?
2. The 4th connection for the switched hot wire will be connected to a 2nd fuse panel I added with relays. So it is only charged when CUCV is running. Is this Good?
3. The battery insulator is 200 amps. Is this no Much? The CUCV alternators are 100amps?
4. Is battery equalizer a better option?

1. Yes, no problem.
2. That doesn't sound right. If you are using an isolator correctly, your auxiliary battery will be charging whenever the vehicle is running. Charging has got nothing to do with the fuse panel.
3. That's great. It just means your isolator can handle more than you are asking it to do.
4. I think your isolator is the best approach.

Here's a quick diagram of what you want to do:

 

[TGP (IL)]

Why not just use the 12v junction block on the firewall by the glow plug relay.
Pretty sure the third battery idea has been covered before.
Try a search.
Tom

 

[stationjj]

To clarify somethings on my Original post.

With my knowledge of DC Electrical connecting a battery isolator should be straight forward.

MarcusOReallyus Thanks for your help. I think I have better understanding on the install. I got confused on the hot wire connection.

The link that wouldn't work is; http://www.steelsoldiers.com/showthread.php?122122-Battery-Isolators

Yes, these subject have been covered before. I did my research concerning adding a 3rd battery and isolator. I had someone suggest buying a vanner battery equalizer for this project. They are EXPENSIVE! If the battery isolator is best approach the cost is under $100.

I needed to verify my understanding. I am no DC electrical expert. The 24/12 volt hybrid system in CUCV can get messy.

I guess it doesn't matter which alternator you connect to?

Thank You

John

 

[MarcusOReallyus]

I guess it doesn't matter which alternator you connect to?

Oh, YES IT DOES!!!!!!!


It matters!

You want to connect to the DRIVER'S SITE alternator. I should have made that clear - my fault.


The passenger side alternator puts out 24v with respect to the vehicle ground, and charges the rear battery.

You want the driver's side alternator, which puts out 12v with respect to ground, and charges the front battery.



Okay, what do I mean by "12v with respect to ground" or "24v with respect to the vehicle ground"?

That "with respect to ground" is a very important concept. If you can wrap your brain around it, you'll find this 12v/24v stuff starts to make sense.


Let me get this posted, and I'll take a few minutes to write up an explanation of that, because it's critical to understand.

 

[Keith_J]

You CAN connect to the back battery as long as you use a dedicated negative wire from the back battery negative post. This would make the negative wire 12 volts to ground. Clear as mud?

I added a 12 volt outlet in my truck off the back battery using a two lead outlet. It works fine as the negative is properly insulated. Why? Because I can use it to measure both battery voltages from inside the cab.

 

[MarcusOReallyus]

Keith, he's clearly stated that he's a newbie with electrical stuff. Let's not complicate things for him, okay?

 

[kdrambo]

but the question now is, he has a duel voltage system now, why the 3rd battery?

 

[jpg]

but the question now is, he has a duel voltage system now, why the 3rd battery?

He mentioned that he has HAM and other items that need power. I presume he wants to isolate them from the starter batteries, so he won't find himself unable to start the vehicle after a long HAM session. I'm looking at doing the same to my M1010, though my "house" bank will likely be 24V so I can use it to run the heater.

 

[ke5eua]

You CAN connect to the back battery as long as you use a dedicated negative wire from the back battery negative post. This would make the negative wire 12 volts to ground. Clear as mud?

I added a 12 volt outlet in my truck off the back battery using a two lead outlet. It works fine as the negative is properly insulated. Why? Because I can use it to measure both battery voltages from inside the cab.

That would be a bad idea since he is wanting to install radios that are also grounded through the antenna system.

Tie into the first battery and save yourself sending your radios in for repair.

 

[tennmogger]

StationJJ, you are setting up your truck as I like to set up my 24v trucks. Having a third 12v battery separate from the truck system not only avoids your running down the truck battery but also isolates (or helps isolate) the radio power from the noisy truck electrical. On a normal 24v vehicle I would normally recommend a 24 to 12 converter to provide charging current for the 'radio battery' but the 1009 is unique in that it can provide the 12v without unbalancing the batteries (well actually they are not so well balanced anyway).

The simple way, and cheapest, is to add a relay that gets powered whenever the key is on. Fuse it of course. Use that relay's heavy contacts to connect the third battery to the 'bottom' 12 volt battery of the truck, plus to plus. This way when you turn on the key and start the truck you do get power for charging the radio battery. Turn off the key and the relay drops out and using the radios will not run down the truck batteries.

A simple system does have complications though. IF the truck battery were dead but your radio battery is not, the truck will try to start using the radio battery. Since the radio battery wiring is not set up for starting current, this would be bad. You can avoid this possibility by putting a 1 Ohm resistor (20 Watt) in series. The resistor can dissipate the current difference between the radio battery and the truck battery (as much as 12v) to save the wiring, yet will pass along plenty of average current to keep the radio battery topped up.

Some might suggest a diode instead of a resistor, and that would work except that a diode drops as much as 0.6 v. Reducing charge voltage by that much can keep your radio battery from getting full charge. Lots of battery isolators have this problem.

If you intend to use the third battery for some high current purpose like running a 12v winch, then forget everything I said! Charging through a resistor works only for low loads such as radios, cell chargers, refrigerator, whatever.

Bob WB4ETT

 

[stationjj]

I want to say thanks for everyone's input. I will respond soon with a better explanation, and my plans.

Today has been a long day. For you HAM radio members. I passed my General test today. A celebration with my girl tonight.

John
KK4LNG

 

[ke5eua]

I want to say thanks for everyone's input. I will respond soon with a better explanation, and my plans.

Today has been a long day. For you HAM radio members. I passed my General test today. A celebration with my girl tonight.

John
KK4LNG

Congrats on the upgrade. Just looked you up on qrz, all I can say is if you were / are in the military I'm sorry, lol

 

[tennmogger]

Congratulations!

I want to say thanks for everyone's input. I will respond soon with a better explanation, and my plans.

Today has been a long day. For you HAM radio members. I passed my General test today. A celebration with my girl tonight.

John
KK4LNG

 

[stationjj]

Hey,

Thank you for congrats on license upgrade. KE5EUA I am not prior military.

Let me better explain my reasoning for adding 3rd battery. Again I am a HAM Radio operator and do a lot of outdoor camping. My girlfriend and I usually do back country camping at Land Between the Lakes. She is wanting to add things to the camping trips. She will suggest an idea, and I figure out how to make it happen. Trying to keep the woman happy! HAHA! Some of these ideas require power. I prefer to use DC and avoid using a inverter. Also I use the truck for HAM Radio emergency exercises as part of the local ARES (Amateur Radio Emergency Service).

Yes, with adding more power needs. I want to avoid draining the front (12 Volt) battery, and getting stuck. KE5EUA, I don't understand your concern on connecting radio to third battery. I currently have a dual band Yaesu Radio wired to front battery and grounded to the chassis. What am I missing here?

I like the battery isolator idea best long term for my needs. I did purchase a NOCO 140 amp battery isolator on Amazon for a good deal.

Thanks for everyone's input.

John

 

[ke5eua]

Hey,

Thank you for congrats on license upgrade. KE5EUA I am not prior military.

Let me better explain my reasoning for adding 3rd battery. Again I am a HAM Radio operator and do a lot of outdoor camping. My girlfriend and I usually do back country camping at Land Between the Lakes. She is wanting to add things to the camping trips. She will suggest an idea, and I figure out how to make it happen. Trying to keep the woman happy! HAHA! Some of these ideas require power. I prefer to use DC and avoid using a inverter. Also I use the truck for HAM Radio emergency exercises as part of the local ARES (Amateur Radio Emergency Service).

Yes, with adding more power needs. I want to avoid draining the front (12 Volt) battery, and getting stuck. KE5EUA, I don't understand your concern on connecting radio to third battery. I currently have a dual band Yaesu Radio wired to front battery and grounded to the chassis. What am I missing here?

I like the battery isolator idea best long term for my needs. I did purchase a NOCO 140 amp battery isolator on Amazon for a good deal.

Thanks for everyone's input.

John

If you connect your radio positive to the cross over cable and ground to the chassis you'll be fine, but if you do it the opposite by putting the ground on the cross over and positive on the main positive wire going to your starter when you connect your antenna it will back feed 24v through the antenna as it completes the 24v circuit.

For what you're wanting to do adding a battery for accessories a 200 amp solenoid would fit the bill perfectly.

Just run a cable from the battery that has the main ground on it, I call it the first battery, to your solenoid then to your aux battery. Tap into a circuit that comes on in the run position and use that to activate the solenoid and you're good to go. It'll save you some money too.

Best way to figure out what battery to use in these situations is to take your multimeter and put the negative lead on a chassis ground and find which positive post on the batteries give you 12v. A hint, it's going to be the one with the main ground coming off it.

You'll get the hang of it, I promise you.

 

[stationjj]

KE5EUA,

I understand what your saying now. When I first install the Yaesu to the truck I did my research concerning grounding. I have to say the ground is good. I haven't had any problems or noise issues.
I am upgrading the Yaesu in CUCV to Kenwood D-710 I got at Hamfest. Sending you PM

I ordered some 4 awg cable to connect everything up to the various batteries and Alternator.

Thanks everyone for your help. I will update post when I get everything installed and tested.

John
KK4LNG

 

[ke5eua]

I loved my 710, even had it tied to the avmap G5 and was great. Radio met a tragic end, still don't know what happened. Replaced it with the new yaesu aprs radio and lost transmit on 2 meters after about a year.

I have a feeling the vehicle it was installed in had a bad alternator and I didn't notice. It was an 82 dodge that ran strong.

If you can swing it having either the avmap or a garmin with the fleet cable from argendata (don't quote me on the spelling) it makes the 710 an awesome rig.

I don't know if they ever figured out how to interface a ps2 keyboard into it like on the one the 710 replaced.

 

[Neophyte]

Isolator is the way to go. I've got a cole hersey for a parallel battery set up (two car batteries).....start using both, use one when running.

 

[MarcusOReallyus]

Isolator is the way to go.

Yep. That's exactly what they were invented for.