Pre-Build - Troopy Electric options 24v to 12v (1 Viewer)

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I'm almost to the point where I'm ready to start a build thread - my '94 Belgium bought Troopy is with Maltec in Germany finishing up it's pop-top conversion, and I have a 1HD-T being rebuilt for install when I have the Troopy in the USA. I've received a lot of great guidance from many of you here, and I need some advice for how to handle the electric system. I've read through the Diesel forum and understand what the various options are, but those aren't always necessarily specific to a long range travel vehicle build, so I thought I'd post and get your thoughts.

The Troopy is running 24v now. I don't think it makes sense to completely convert the vehicle. That basically leaves two options, as I understand it. 1) run a second 12v alternator to a third battery and power the accessories off of that, or 2) use a DC/DC converter from the two current batteries to charge a 3rd 12v battery. Is there any advantage/disadvantage to either of these options? It seems the difference is just alternator vs converter, but does connecting the to two cranking batteries have any drawback?

The plan is to have the usual suspects connected to this - winch, fridge, compressor, lights, water pumps, etc, including an input for solar charging.

Tagging a few of you that have been so helpful so far, but open to everyone's input that has experience with this. Thanks in advance!
@umpqua @gilmorneau @joekatana @SNLC @c2dfj45 @divemedic
 

divemedic

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First, I’m very flattered to be included in that list. With that said, here is my advice:

Leave the factory 24v system as intact as possible. If you start cutting into it, only do it to make (proper) repairs. 24v systems are inherently more reliable and efficient.

I personally run my winch and aux lights off the 24v system. Everything else is/will be off the third battery. A 24v winch runs way faster than a 12v. Draw is roughly half the amps on 24v compared to 12v. Example a high-end LED aux light may draw 10A on 12v, but 5A on 24v. So running aux lights is just more efficient and worth adding to the factory electrical. In this case, I only used the power box to create ACC and Ign power for relay switching. Power is supplied by direct battery wiring.

Everything else is on my third battery or will be on my third battery. It’s managed by a redarc. Which works by voodoo and science. But it does work and thus far has proved perfect.

I do plan on adding a 60l fridge in the back and a console fridge upfront and solar to the truck after I move to California. The redarc will support that autonomously. Again voodoo.

I’ve got some sneaky s*** planned for audio. It will be based on my 12v system too.

Other tips, I only use 24v relays in my truck. A 24v 30A relay is good for 60A on 12v

I run 1 size up on wire gauge than what’s needed. Because I’m stupid paranoid of fire.

I do not use solder for any connections. By a quality stripper (hehehe) and crimper.

Avoid grounding to the body if you can. I run bluesea fuse boxes with battery grounds.
 
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SNLC

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I would add a 2nd alt to run your 12v battery. Keeps all your 24v system intact and keeps the 12v very simple. This way you will never have an issue with draining your starting batteries down, ever. Any solar can be kept to the 12v system, essentially leaving the 24v system stock and untouched.

Also, you can get a monster battery for your 12v side and the same for the alt. A Mean Green could be adapted just like any other and it puts out 300amps at idle. ;)

It's unfortunate Toyota didn't do the 24v 70-series the way they did the 81's. Had they, converting to 12v is very simple since the 81's only use 24v for starting.

Cheers
 

divemedic

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I would add a 2nd alt to run your 12v battery. Keeps all your 24v system intact and keeps the 12v very simple. This way you will never have an issue with draining your starting batteries down, ever.


It's unfortunate Toyota didn't do the 24v 70-series the way they did the 81's. Had they, converting to 12v is very simple since the 81's only use 24v for starting.

Cheers

But if a relay goes bad on you bulldozer you could liberate a wiper relay from the 70:rofl:
 

divemedic

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Absolutely. I watched it happen (kind of) Antarctica but it was for a crusty snow cat that was needed in service for dive tending.
 

gilmorneau

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hoser

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The plan is to have the usual suspects connected to this - winch, fridge, compressor, lights, water pumps, etc, including an input for solar charging.
Everything you mentioned is available in 24v. Most fridges already are 12/24v compatible. 24v USB plugs are easy to come by too. The only component I don't see a lot of choices are for 24v 2M radios. I would run 24V. It puts a smile on my face every time I start my 24V trucks.... they just fire up so much faster.

If we weren't stuck to this 12V standard, vehicles would've been 48 Volts a long time ago.
 

divemedic

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Everything you mentioned is available in 24v. Most fridges already are 12/24v compatible. 24v USB plugs are easy to come by too. The only component I don't see a lot of choices are for 24v 2M radios. I would run 24V. It puts a smile on my face every time I start my 24V trucks.... they just fire up so much faster.

If we weren't stuck to this 12V standard, vehicles would've been 48 Volts a long time ago.

depending on what your charging, 24v usb is safe for electronics. I do have a few double USB ports on 24v acc. Gopro, iphone, and ipads are good to go. I assume othersimilar devices are too.
 

SNLC

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Everything you mentioned is available in 24v. Most fridges already are 12/24v compatible. 24v USB plugs are easy to come by too. The only component I don't see a lot of choices are for 24v 2M radios. I would run 24V. It puts a smile on my face every time I start my 24V trucks.... they just fire up so much faster.

If we weren't stuck to this 12V standard, vehicles would've been 48 Volts a long time ago.

This is true as well. Head unit about all I can think of that is a pain to get in 24v. I just think 12v is easier to work with, much more common for well everything and it would not be hard to have a 2nd 12v system fitted.

Cheers
 

hoser

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Yeah, definitely could go either way. If car audio is your thing, then definitely 12v. The winch should be 24v no matter what as it should run off the starting batteries and alternator. It might be tight to fit a 3rd battery in the engine compartment and so if it's is mounted towards the rear of the vehicle, 24v would need much smaller cables.

24v has a clear advantage when it comes to 120V inverters... more efficient and cheaper. Webasto heaters are available in both 12/24v versions. LED lighting.... 24v. What else is there?

One of these for all your accessories is all one should need (unless planning on induction cooking).

Compared to an AGM battery, it's half the weight and rated at 3000-5000 cycles which is about 10x that of an AGM battery.
 
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Appreciate the responses guys. For simplicity, I think the first choice route will be to explore sticking with 24v all the way. I hadn't considered that, thanks @hoser.

If I'm understanding amps correctly, the 12v rating on the fridge power consumption would be cut in half on a 24v system? So a 50Ah 24v battery would last plenty long between charges? I can run an IBS dual battery system like in my 100 series and charge the LiFePO4 from the stock alternator, and isolate the cranking batteries when not running.
 

divemedic

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^ Yes and yes.

Side note: Don’t let audio scare you off. Very good audio is available. Marine applications is what to look at. JL comes recommended and they have good 24v amps.

also, good taste in trucks

0BEE1282-711A-4D2A-8A2F-D56D838A94D8.jpeg
 

umpqua

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Hi Oliver, thanks for checking in on your build. You're really going to have a nice truck when this is finished. I'll be interested to see how the Maltec top turns out. As you know, I have the AluCab Hercules top.....there are some things that I like about the top but some other things that are less than ideal. I guess you'd get that with anything though. You'll love the HDT. Lot's and lots of power and torque there for sure.

I agree with others that I would leave the 24v system intact. I think if you start messing around with that you could be forever chasing down electrical issues. Really good idea to use a 24v winch. I don't have lights yet but those will run on 24v as well. If anyone has solid leads on old school Cibie type 24v lighting please pass it along. I have a 24v compressor mounted under the truck for air up and the front and rear lockers. Everything else that I have is running from the 100amp hour 12v lithium battery. Refrig, lighting, heater, soon to be water pump, water heater and the 1000w inverter which I only use with a running engine with the 12v alternator charging as inverters are super energy inefficient. I "really" like knowing that my truck is going to start if I sit for an extended period of time no matte what is going on with the 12v accessories. And that's a period on that.

The only thing that I might have done differently is to put in a 200 or even 300amp hour Lithium. I just recently camped in 20 degree weather and ran the heater a lot. The 100amp will run about a day before needing a boost. I have a solar blanket but may do a roof mounted solar panel soon. It would be easier for no hassle use. Nothing to set up. I don't even have a stereo hooked up yet. I have a Bose speaker that seems to fit my immediate need but I'm old. Pretty soon I will look into a stereo though and I'm also interested in a backup camera. Ideally I'd continue to go 12v there.....see the truck always starting comment. I may also look into a bigger 12v alternator as well.

Anyway, you're well on your way to a super nice setup. Keep us informed and I hope to see it someday.

Rodney.
 

hoser

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If I'm understanding amps correctly, the 12v rating on the fridge power consumption would be cut in half on a 24v system? So a 50Ah 24v battery would last plenty long between charges? I can run an IBS dual battery system like in my 100 series and charge the LiFePO4 from the stock alternator, and isolate the cranking batteries when not running.
Correct... 50Ah 24V battery is equivalent to a 100Ah 12V battery for fridge run time. The LiFePO4's can also be safely run down to 20% State of Charge... vs 50% for an AGM battery.

Yes, you can run an isolator like in your 100 but ideally you would be adding a DC to DC charger with a more optimal charging algorithm for the LiFePO4 battery.
 
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Got it! Thanks @hoser It's starting to make sense. So I can use something like redarc that @divemedic is using, which would receive input from the 24v alternator, have solar capabilities, and charge the aux battery. If I want go with a bigger Ah as @umpqua is suggesting, is there any difference/advantage to using two 24v 50Ah LiFePO4 in parallel versus two 12v 100Ah in series? Reason I ask, the starter batteries are 12v in series, so if there is ever a dead starter battery, perhaps you can swap in the LiFePO4 to get the vehicle started.

I suppose a manual relay between the starter and aux batteries could work to jump a dead starter as well.
 

divemedic

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If it were me and I was budgeting for fresh build based on what I’ve learned:

2 new oddessey or Toyota start batteries. Accessories on it:

- comeup DV12 24v (I like cables over synth)
- Aurora 7” spots x2
- BD S2 pro x6 (2 in the wings of my arb flush-mounted. 2 left/right facing on the rhino cross bars, 2 rear facing)

accept the winch, that’s a potential of 14A on the start batteries.


Aux 12v system managed by Redarc BCDC1240

I’d use a Lead Crystal battery for the aux battery and supplement it with a Grape monocrystalin 180w panel on the roof and second blanket I could move around.

Lead Crystal has a lot of good characteristics for this application, namely cold tolerance and they will absorb solar input much more efficiently than lithium.

Main accessories:
- Dometic cdf11
- Engel MT60F
- BD S2 pro in red light x3 (right,left,rear)
- Ham and CB
- USB x6
That’s about 17A/hr with 1A draw on each USB port.
 
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gilmorneau

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Maybe it's in the thread and I missed it, but if the OP is putting a 1HD-T in a 24V truck, won't he need to swap in a 24V glow system (and maybe fuel shut off, etc)? Most 1HD-t's come out of HDJ80's, which are either 12V or 12/24v. Doesn't seem like a big obstacle, but worthy of mention.
 
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@divemedic you're making it too easy! Add to Cart -> Checkout :rofl: Thanks! My list is pretty similar, appreciate the insight.

@gilmorneau - yes, I already have a 24v fuel shut off ordered for the 1HD-T. For the glow system, I was hoping the one from the 1HZ in the truck will work?
 

umpqua

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I'm glad I checked into this thread.

Hijack I know but I'd like to find some 24v driving/spot lights. I checked the aurora Aurora Off-Road Lighting Solutions - LED Bars - USA Based, Better than Rigid site and didn't see much of anything. Maybe they are having trouble with their website.

Even further rabbit hole hijack...forgive me.
A couple of weekends ago I camped in temps that dropped into the low 20's. Ran the heater quite a bit. Lights. It was cloudy and under evergreen shade so I didn't put out the 200w solar blanket. Got there Friday afternoon and left Sunday morning. I noticed on Saturday late afternoon that the 100amp Lithium volt meter had dropped to about 10v. I started the truck and let it run for 30 minutes or so and brought the battery back up to about 13. Turned off the truck, went to bed that night with the heater still running. Woke up the next morning (Sunday) and the 12v had completely gone dead. No power to any 12 accessories. Drove the truck home (90 mins) and the 12v system is still completely dead. I went by batteries plus and they put a volt meter on the battery and it was less than 2amps. I took the truck home and plugged in the shore power. I have a Sterling charge controller that set for Lithium. Quickly it brought the battery back up to charge. Looking under the hood I discovered that a breaker had flipped between the 12v alternator and the battery. I understand the breaker might have tripped because the battery was too low for the alternator to charge.

The Lithium battery that I use supposedly has an on board "BMS"; battery monitoring system. It will shut the battery off if it discharges too low or turn it off in an overcharge situation. I have nothing between the 12v alternator and the lithium battery.

Should I be running something between the alternator and the lithium or is it ok to rely on the BMS?

I'm a mechanical moron and Divemedic or anyone else please school me on what's what. If I was doing anything over again I would buy at 200amp lithium battery. It's my first time using one and honestly I think I've had better luck with the tradition lead acid battery. It's what I know.

Thanks.
 

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