Victron Energy: Alternator/Solar Charging - LFP Battery System

[shade]

I'm installing a new house electrical system in my 2012 Toyota Tacoma, and I'd like some guidance on how best to go about building one with Victron Energy components.

I've divided the plan into three sections: Alternator Charging, AC Charging, and the Full System.

I'll be charging a 160Ah LFP battery, along with my truck's Group 31 starting battery, via the truck's 130A alternator and a fixed 360W solar panel; no AC charging. I'm not interested in having the capability of combining the output of both batteries; in fact, I'd rather not. My main house load is currently a fridge, but I plan to use the system to heat small amounts of water, cooking, and a small microwave oven once an inverter is added. Other than a few small fans for my pop-up camper, there'll be no HVAC loads.

When general schematics are used, important details like fuses and switch gear won't always be shown. I'll save that for the detailed schematic. I've included links to the Victron product & manual pages. With few exceptions, I'll probably buy most of the components through PKYS.com.

Thanks in advance for your help, and please feel free to point out alternatives, suggestions, or mistakes. As the plan develops, I'll post updates here in the opening post.
_____________________________

Nordkyn Design: Lithium Battery Systems - This series of articles is very informative.

Marine How To: LiFePO4 Batteries On Boats - One of many helpful articles by Rod Collins.

Victron Energy Resources

Main Download page
Wiring Unlimited eBook - Rev 04
Energy Unlimited eBook - Revision 9, June 2011
Victron Energy Community forum
Victron Toolkit
Victron MPPT Sizing Calculator
Victron battery cable doc

 

[shade]

Alternator charging
(Updated 10-16-2019)

Victron recently released a new DC-DC charging option, the Orion-Tr Smart. I'm going to use the 30A model. This is a simpler solution than other options I was considering, and at 30A, it shouldn't pose a threat to my truck's alternator.

I'll run all charge sources through a single 220A BatteryProtect, and all loads through another 220A BatteryProtect. I don't have any critical loads that need power no matter the damage it may cause, like a boat's bilge pump or auto-pilot.



Parts List for Alternator Charging

Orion-Tr Smart DC-DC Charger Isolated 12/12-30, Part: ? - manual
LFPSmart 12,8/160 battery, Part: BAT512116410 - manual
VE.Bus BMS (Battery Management System), Part: BMS300200000 - manual
BMV-712 Smart Battery Monitor, Part: BAM030712000 - manual
Smart BatteryProtect 12/24V-220A battery isolator, Part: BPR122022000 - manual
Assorted control cabling

 

[shade]

AC Charging
(Benchtop Power)

Volteq (Mastech) HY3020EP Programmable DC Power Supply 0-30V / 0-20A

I've been needing a good, general purpose battery charger, and I also wanted one that was programmable so I could charge an LFP battery properly. There aren't many AC chargers set up for LFP charging, and Rod Collins of Marine How To uses similar Mastech power supplies. I spent a little more to gain programmability, which I hope (no online manual) will allow me to create my own charge profiles for whatever is connected.

During its initial use, I found this unit to work fine for LFP battery charging. I set it to run at 10A/14.2V (3.55V per cell) cutoff. Once the overvoltage cutoff shut down charging, I allowed the battery to rest a few hours, and used the internal timer to hold the voltage at 14.2V for an hour to top balance the cells. At the end of that cycle, the current draw was >1A, meaning it was at roughly 100% SOC.

After 12 hours of resting, the battery was at 13.52V, and I connected a load so it could be stored at a lower SOC.

 

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Full System Overview, MkIV
(10-17-2019)

 

[luthj]

You may consider using a simple relay for alternator charging. The relay would get its power from the D+ signal (alternator enabled signal). Then provide the relay coils ground via the battery monitor. Victron lets you set logic for the relay control outputs on the monitor, so you would set BMV to open the relay when the SOC or battery voltage reaches a certain point. With your toyotas fairly low alternator voltage, charge rates can easily be controlled by selecting the gauge of the charge circuit.

 

[pdxfrogdog]

I run a custom built battery box that lives in a FrontRunner Wolfpack box. The box contains a BattleBorn 100AH 12V battery, a 1500W inverter, a Victron BMV 712, a Victron 75/15 MPPT and a blue sea fuse block that connects all the various 12V ports that are mounted to the outside of the case. I wanted it portable so it could be moved between vehicles as well as the house since it is a component of our 72 hour kit. When it came time to add a way to charge off alternator, the easiest and cheapest ($100) for me was to mount a Victron Orion TR 12 to 24V converter in my jeep and run the 24V output into the box's solar input. It works great and the charging profile is the same as when my solar suitcase is deployed. The Orion TR is fairly small and can be attached to a low amp switch which I've wired to both a physical switch and my ignition so I have full control over when it is energized without having to worry about it being left on when the vehicle is parked. This is not exactly a high amp charging solution, but the Orion TR will output sufficient current at 24V that my MPPT maxes out at 15A continuous. It is actually my fastest way to put energy in the box... faster than my 180W suitcase or even my home 120V AC charger which is limited to 10A. Since Lithium doesn't care about being fully charged it has been a great solution. And who cares about the inefficiency of 12V to 24V to 12V conversion... its the alternator. Got my Orion TR from PKYS, for some reason they don't show the model on their website, but Peter was able to get it to me quickly. Anyway, this isn't likely what you are looking for, but it has worked great for me.

Edit: Link to Orion TR data sheet. I've got the 12/24-10 240W version:

https://www.victronenergy.com/upload/documents/Datasheet-Orion-Tr-DC-DC-converters-isolated-100-250-400W-EN.pdf

 

[1leglance]

I am subscribing to this thread since I really like the Victron bits in my Tacoma but I need a whole new setup for my Transit....
I also prefer a 1 stop shop which is why I was looking at the Redarc Manager 30 since it gives me solar, alt, battery isol & shore power....but the solar panel requirements are pretty narrow and the Manager 30 is $1200

Really looking forward to this thread, thanks

 

[dreadlocks]

here's what Victron App gives LFP's:


but digging into Victron's dbus API here: https://github.com/victronenergy/venus/wiki/dbus#battery

specifically:

/Info/MaxChargeVoltage      <- Maximum voltage to charge to
                               (BYD, Lynx BMS and FreedomWon)
/Io/AllowToCharge
/Io/AllowToDischarge

Looks like if you hooked something like a RPI w/VenusOS, with a bit of scripting you could easily control when and to what extent to charge off the vehicle's alternator..

 

[pdxfrogdog]

I really like Victron gear and would love to have that level of transparency inside the battery, all aggregated into a nice app like Victron Connect.

 

[shade]

I really like Victron gear and would love to have that level of transparency inside the battery, all aggregated into a nice app like Victron Connect.

@dreadlocks' recent Battle Born experience is one of the reasons I want that level of access. It's ridiculous that the internal BMS data required to fully diagnose the fault is there, but inaccessible to anyone but the manufacturer.

 

[pdxfrogdog]

@dreadlocks' recent Battle Born experience is one of the reasons I want that level of access. It's ridiculous that the internal BMS data required to fully diagnose the fault is there, but inaccessible to anyone but the manufacturer.

Yep, I'm following that thread. I can also see why a manufacturer would not... that's consumer electronics. I'm reserving judgement on Battle Born pending how they handle the warranty claim.

 

[shade]

Yep, I'm following that thread. I can also see why a manufacturer would not... that's consumer electronics. I'm reserving judgement on Battle Born pending how they handle the warranty claim.

I'm not condemning BB, but I know I'd prefer better BMS access than they offer.

As long as it's just delivering data, with no end user input possible for changing any BMS parameters, I think they should allow access to anyone sharp enough to want it. I can certainly understand not giving customers full control of the BMS, though.

 

[shade]

You may consider using a simple relay for alternator charging. The relay would get its power from the D+ signal (alternator enabled signal). Then provide the relay coils ground via the battery monitor. Victron lets you set logic for the relay control outputs on the monitor, so you would set BMV to open the relay when the SOC or battery voltage reaches a certain point. With your toyotas fairly low alternator voltage, charge rates can easily be controlled by selecting the gauge of the charge circuit.

How about adding a Cyrix-Li-ct relay (ignore the MultiPass)?



From what you're saying about controlling charge rate, I would determine the length of the cable run from the starting battery to LFP battery, and select a wire gauge that will deliver the desired amperage. That would remove the need for the BMS 12/200, but it wouldn't allow adjusting the charge rate, would it? I'm thinking it might be good to have more control of the charge rate so I can maximize whatever the alternator is capable of producing without stressing it too much.

 

[dreadlocks]

eh, given LFP's ability to sink massive charge rates, I would not rely on cabling to limit charge current like I would a lead battery.

 

[shade]

eh, given LFP's ability to sink massive charge rates, I would not rely on cabling to limit charge current like I would a lead battery.

That's my concern, especially if I ever increased the capacity of the battery bank. How are you limiting yours?