Looking for input - removable LiFePO4 solution with alternator/solar charging

kiloxraysierra

kiloxraysierra

New member
Hi Folks,

I have a RAM 1500 (gasser) that is my daily driver. After a year of waiting, I picked up a GFC camper in December. I chose this camper because I like that it is mainly a truck cap with a wedge tent on top - the truck bed can still be used as a truck bed. The plan is to load up what I need for the weekend (or the occasional 2 week trip) on Friday and pull it all back out on Sunday night. Most of my camping is in the spring/summer/fall, mostly weekend trips with occasional 2 week trips where I'm never in the same spot for more than 2 days.

I will have fairly modest power needs in the bed of the truck: ARB 37qt fridge, maybe some LED lights, USB ports for charging iPhone/iPad and maybe an infrequently used HAM radio (FT-818ND or FT-847). I already have a 50AH Bioenno Power LiFePO4 battery in a PowerWerx battery box with an added ARB specific 12V plug port. I'm aware of the temperature charging restrictions for LiFePO4 batteries and at the moment, I don't think this will be an issue. Any cold weather trips will be short enough that the battery shouldn't need a charge at all.

To use the fridge in the back seat of the truck last summer, I ran wires (10AWG/15A fuse) direct from the battery stud in the engine fuse box & a ground near the battery to the ARB 12V plug I installed in the back seat. I plug the fridge into the truck while driving and then switch to the battery box when I arrive in camp.

I would like the solution in the bed of the truck to be a bit more "plug it and forget it", so I've been reading through the forums and putting together bits and pieces that I think should do the trick. I'm no electrical engineer though, so I'm hoping some of you kind folks can provide some feedback. I'm not tied to any of the bits I have now, so definitely willing to entertain alternatives.

Dedicated +/- cables from the engine bay (battery stud in fuse box, nearby ground). Probably 4AWG as this is likely 15ft one way (30ft round trip) with a 30A fuse on the + side right at the battery stud. I'd like to terminate with a SB50 PowerPole connector mounted in the bed (should probably have a 30A fuse here as well).

Everything else will go in a hard box that can be removed. I'll have another SB50 PowerPole connector mounted on the box as input to a Blue Sea ML-ACR (7622). I probably won't use the engine isolation features or the remote control. This will be the input to a Victron Orion-Tr 12/12-18 set to 14.5V output feeding the Power Supply input of a West Mountain Radio Epic PWRgate. The 50AH LiFePO4 will be the battery (charging limited to 10A by the PWRgate) and at some point in the future I may add Solar directly to the input on the PWRgate. The Load Out leads will connect to a Blue Sea 5025 Fuse Block with appropriate fuses to run panel mounts in the hard case for the ARB 12V plug, USB plugs and probably 12V socket plug as well.

Friday night I load everything up, connect a jumper between the SB50 in the bed of the truck and the hard box and I should be good to go, right? ?

I am a bit concerned the ML-ACR won't function correctly in this configuration... I want to ensure the hard box isn't pulling from the starter battery when the truck is turned off.

Looking forward to your feedback.
 
kiloxraysierra

kiloxraysierra

New member
Forgot to mention I have a DC fan controller that will run two fans. I think it turns on/off around 30C. I'd set one fan to suck and the other to blow so there is some airflow in the box.
 
SquirrelZ

SquirrelZ

Member
I'm no expert either as I've only built 1 camper van and had a 37' boat with a fairly complicated electrical system.

I'd suggested qualifying your electrical needs more precisely. "Fairly modest" is helpful but numbers are better. Estimate how much power each device will use and for how long. I looked briefly for how much power the ARB 37 frig draws but didn't find a number. That seems to be you biggest power draw.

With a 50 Ah battery, it seems like your system is over designed. The Blue Sea ML-ACR is rated for 500 amps! Does your truck even produce half that much power with its alternator? And you seem to be feeding way too much power into the PWRGate which only charges at 10 Amps.

I don't understand why you're putting 30 amps fuses at both ends of the 4 AWG cable? With detectable fittings on each end of the cable, just have one breaker in the cable. 4 AWG at 30 amps works with 35 feet of cable. That's a lot of heavy cable to use for a 10 amp charger, the West Mountain Radio Epic PWRgate . (I used the Blue Sea Circuit Wizard for my calculations.)

The Vicron and PwrGate seems like an expensive way to make a battery to battery charger. There are dedicated battery to battery chargers that would do just fine with your battery. One CTEK model even has a built in MPPT controller.

Good luck with your project!
 
R

Rbertalotto

Explorer
I just posted my bench test of the Renogy DC To DC charger. I have exactly the same needs as you but withva Rooftop Tent. Permanently mounted wire to rear of truck. Portable battery box in bed for weekends. Using Renogy DC to DC to charger while traveling and folding portable solar panels to charge while camping. And my system will be movable between two vehicles and a boat. Lots of research and experience and this is in my opinion the best solution.
 
shade

shade

Well-known member
What is the purpose of the PWRGate in your design?

Epic PWRgate - West Mountain Radio

www.westmountainradio.com

Have you considered using a product from the Victron Orion-Tr Smart line? They should be available in North America by the end of this month, and may be a better choice for your application than an Orion-Tr. The 12/12-30 model should charge your LFP battery quickly and safely, but you could use a different model if you really want to limit charge current to 10A.

Orion-Tr Smart DC-DC Charger Isolated - Victron Energy

The Orion-Tr Smart DC-DC charger is a professional DC to DC adaptive 3-stage charger with built-in Bluetooth. For use in dual battery systems in...
www.victronenergy.com www.victronenergy.com

www.victronenergy.com

New Product: Orion-Tr Smart DC-DC charger - Victron Energy

The new Orion-Tr Smart DC-DC charger is designed for use in dual battery systems in vehicles or boats, where the (smart) alternator and the start battery are used to charge the service battery. The model range is suitable for 12V or 24V systems, and both lead acid and lithium batteries. Why do...
www.victronenergy.com www.victronenergy.com
 
kiloxraysierra

kiloxraysierra

New member
SquirrelZ said:
I'd suggested qualifying your electrical needs more precisely. "Fairly modest" is helpful but numbers are better. Estimate how much power each device will use and for how long. I looked briefly for how much power the ARB 37 frig draws but didn't find a number. That seems to be you biggest power draw.
Click to expand...

I haven't measured it, but I've seen references to 0.85 Amps/hour draw on a few websites in reference the 37qt fridge. Agreed if I was living in this thing, or didn't already have the battery I should get into the weeds and figure out my exact needs. Having the battery already, I'm sort of in "see how far I get" mode as far as capacity is concerned.

SquirrelZ said:
With a 50 Ah battery, it seems like your system is over designed. The Blue Sea ML-ACR is rated for 500 amps! Does your truck even produce half that much power with its alternator? And you seem to be feeding way too much power into the PWRGate which only charges at 10 Amps.
Click to expand...

Overthought and over-design are definitely problems I deal with, lol. My thinking on the ML-ACR is that the next option down was only rated for 120 Amps, and the alternator is definitely bigger than that. The PWRGate is a bit like a UPS system - it will feed the loads directly from the alternator if power is there, while charging the battery separately, so it can definitely pull more than 10 amps. Looking closer at the Victron though - it does have a switch input, so maybe I just connect that to a switched circuit and eliminate the ML-ACR altogether.

SquirrelZ said:
I don't understand why you're putting 30 amps fuses at both ends of the 4 AWG cable? With detectable fittings on each end of the cable, just have one breaker in the cable. 4 AWG at 30 amps works with 35 feet of cable. That's a lot of heavy cable to use for a 10 amp charger, the West Mountain Radio Epic PWRgate . (I used the Blue Sea Circuit Wizard for my calculations.)
Click to expand...

Well, I was thinking there is a battery at both ends of that wire, but now that I think about it, the PWRgate should never be trying to charge the starter battery, so a single breaker should do the trick. I chose 30A fuses because the Victron has a max output voltage of 25A and a short circuit output current of 40A, and I don't think I should have loads over 30A on the circuit when driving - honestly, don't think there should be more than 15-18A while driving. The ham radio definitely won't be in use at that point.

SquirrelZ said:
The Vicron and PwrGate seems like an expensive way to make a battery to battery charger. There are dedicated battery to battery chargers that would do just fine with your battery. One CTEK model even has a built in MPPT controller.
Click to expand...

I priced out a CTEK D250SE, but it's way more spendy than what I have in the Victron & PWRGate - plus I can reuse the PWRGate in my ham shack if it doesn't work out here.

SquirrelZ said:
Good luck with your project!
Click to expand...

Thanks for your input, gave me a few things to think about!

[Edit: added estimate of 15-18A max load while driving]
 
kiloxraysierra

kiloxraysierra

New member
Rbertalotto said:
I just posted my bench test of the Renogy DC To DC charger. I have exactly the same needs as you but withva Rooftop Tent. Permanently mounted wire to rear of truck. Portable battery box in bed for weekends. Using Renogy DC to DC to charger while traveling and folding portable solar panels to charge while camping. And my system will be movable between two vehicles and a boat. Lots of research and experience and this is in my opinion the best solution.
Click to expand...

Thanks for the suggestion - I'll look into that!
 
kiloxraysierra

kiloxraysierra

New member
shade said:
What is the purpose of the PWRGate in your design?

Epic PWRgate - West Mountain Radio

www.westmountainradio.com
Click to expand...

It has a few purposes.

1. Battery charger. The Bioenno folks recommend only using their power bricks for charging (14.6V, 10A output), so I like that the PWRGate has a similar profile available.

2. Directly power loads from the alternator when underway. Should help the battery charge faster.

3. MPPT controller for when I add a solar panel later.

4. If it doesn't work out here, I can reuse it as a UPS backup device in my ham shack.

shade said:
Have you considered using a product from the Victron Orion-Tr Smart line? They should be available in North America by the end of this month, and may be a better choice for your application than an Orion-Tr. The 12/12-30 model should charge your LFP battery quickly and safely, but you could use a different model if you really want to limit charge current to 10A.
Click to expand...

If I'm reading correctly, the advantage to the Smart line is the Bluetooth connectivity and app? Functionally the Orion-Tr is doing the same thing, without the monitoring or remote programming capability? Or is there something else I'm missing that would help me out?

Thanks!

[Edit: Updated bioenno power brick output from 12V to 14.6V]
 
Last edited:
shade

shade

Well-known member
Being a Victron dealer, @Justin Cook may have some insight about the differences between the Orion-Tr & Orion-Tr Smart. I believe the Smart models have additional monitoring & programmability.

I'm betting a Victron MPPT charger will do a better job than whatever the PWRGate offers for your solar charging, and one of the Orion units should allow you to customize the charging profile to whatever that battery wants. I'll bet that external Bioenno charger outputs at higher than 12V, or it's powering another charger inside the battery box.
 
Justin Cook

Justin Cook

Member
shade said:
Being a Victron dealer, @Justin Cook may have some insight about the differences between the Orion-Tr & Orion-Tr Smart. I believe the Smart models have additional monitoring & programmability.

I'm betting a Victron MPPT charger will do a better job than whatever the PWRGate offers for your solar charging, and one of the Orion units should allow you to customize the charging profile to whatever that battery wants. I'll bet that external Bioenno charger outputs at higher than 12V, or it's powering another charger inside the battery box.
Click to expand...
So, yes, the naming convention is unfortunate, because the Orion-Tr and the Orion-Tr Smart are actually two entirely different products. The Orion-Tr is just a voltage regulator/converter; the Orion-Tr Smart is a true battery-to-battery charger, with three-stage customizable charging profile, settable on/off voltage triggers (to tell it when your vehicle is running or not), etc. The fact that Victron kept the Orion name for an entirely different product is a matter of great consternation among Victron distributors :-/
 
shade

shade

Well-known member
Justin Cook said:
The fact that Victron kept the Orion name for an entirely different product is a matter of great consternation among Victron distributors :-/
Click to expand...
I'll bet. It's hard enough to keep it all straight. Have your Orion-Tr Smarts arrived yet?
 
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