I spent a tremendous amount of time reading, researching, planning and installing this project, but I'm finally happy with the results. I am by no means an expert on lithium, but I'll offer the details of my installation as another data point for anyone considering their own project. I learned a lot in my research, but I learned at least as much during the project as I started assembling and seeing how things worked or didn't work together. Fair warning, this project is not for the budget faint of heart. You could absolutely spend a lot less than I did and at the end I've pointed out the easy areas to cut back. Our coaches use way too much electricity to ever be practical for extended periods of time on batteries, but I wanted the ability to be on batteries with nothing to worry about for at least a day and ideally a weekend and I wanted the batteries to be charged as we drove to the next destination.
Major hardware:
4 x 12V 460Ah V1 Elite Series lithium batteries
4 x Victron Energy Orion XS Smart DC to DC Battery Charger 12/12 50A
3 x Victron Energy SmartShunt IP65 Battery Monitor
1 x Victron Energy Cerbo GX MK2
1 x Victron Energy GX Touch 70, Display
Not related to lithium upgrade:
1 x Victron Energy Blue Smart IP22 Smart Car Battery Charger 12V 15A
(You will need some way to do the initial slow charge on the lithiums, if you don't have anything else, this charger will work.)
Specs:
- 1,840 Ah combined capacity
- It's very hard to calculate meaningful numbers that translate to real world usage, and I haven't done any controlled testing, but that should give me an easy 24 hours of continuous use without running the AC and maybe 7-8 hours with 1 AC running nonstop.
- 200-amp charge capacity while driving from 4 x DC to DC chargers equates to roughly 4-5 hours of driving to get to 100% charge from 50%
- 250-amp charge capacity while plugged in from 2 x Outback VFX2812M inverter/chargers equates to roughly 3-4 hours plugged to get to 100% charge from 50%
Installation notes:
- I disconnected the cable from the battery isolator to the inverter bay on both ends and tagged it out of service. This leaves the alternator charging the lead acid chassis batteries just as it came from the factory. While the engine is running, the DC-to-DC chargers detect the higher voltage from the alternator and pull as much charging current as available and needed to charge the lithiums. This provides the lithiums with the optimum charge profile to full charge them and maximize their lifespan. The alternator is rated at 340amps so even at max pull from the charges that leaves it well below its capacity.
- I replaced the original automatic VSS switch with an electronic manual only emergency parallel. This prevents the switch from automatically engaging due to the mismatch in voltage between the two battery types but still allows me to temporarily engage it from a button on the dash if the chassis batteries need a boost.
- Because I was going from 6 lead acid to 4 lithiums, I had extra 3/0 cable from the original battery cables and used two pieces of that in parallel anywhere the full voltage would be carried (battery busbar to main shunt, to inverters, etc.)
- The high-end busbars are expensive, but sure made things go together easier. The busbar designed for the Victron mega fuses worked well, but you should be able to find something else just as good. When I ordered the Victron fuse holders I thought they came with the fuses but they are separate.
- I purchased some lugs that screw into the battery terminals and allow you to use the traditional battery connectors used on the lead acid batteries, but they never felt tight to me. I was afraid I would damage the batteries if I continued tightening and a lock washer didn't seem like a good idea. I ended up putting ring terminals on the cable ends for a good solid connection.
- It took me quite a while to get my Outback charger settings dialed in correctly and at some point, I had what I thought was a brilliant idea that involved the Blue Smart IP22 charger. Long story short, it didn't work, so I had an extra charger. My chassis batteries aren't as strong as I would like them to be, but I need a break from spending on batteries, so I installed the Blue Smart charger as a battery maintainer on the chassis batteries when plugged into shore power. Between that and the boost switch I think I'll be able to extend the usable life of the chassis batteries considerably. The central vac is installed in the bay next to the batteries and it is only powered when plugged in, not from the inverter, so I was able to plug the charger into the same outlet after drilling a hole through the compartment wall.
Outback settings:
Determining the right settings to use for the inverters was considerably more difficult and time consuming than I expected. There is some voltage drop across the cables by the time they reach the inverters and that a layer of inaccuracy. I retrospect, I should have called it "good enough" a lot earlier.
Here is what I ended up with:
1. charger limit = 14 AMPs AC
2. absorb volts = 13.8 (lower to avoid Epoch Elite v1 high charge current limit)
3. absorb time limit = 1 hour
4. float volts = 13.7 (must be lower than absorb)
5. float time = 6 hours (batteries need to fully recharge after refloat setpoint)
6. refloat volts = 12.6 (this is the max)
7. equalize volts = 14 is min
8. equalize time = 0 = never equalize
9. AGS = 13v = not hooked up
10. Chargers in Auto mode
11. Temperature sensor unplugged to prevent temp compensation
* I think it should be possible to use the relay output from the Cerbo GX to start and stop the Outback charges, but that would require a lot more research and a wire to be ran from the Cerbo to the Outbacks. I'll monitor how these settings work this summer and if needed I may investigate that option.
These are my settings for the DC-to-DC chargers:
Victron Orion XS charger settings:
1. Engine shutdown detection
a. Disabled
b. Use voltage instead
2. Input voltage lockout
a. 13.6 and 13.7
3. Battery settings
a. Absorption voltage 13.9
b. Adaptive absorption off
c. Absorb time 0
d. Float 13.5
e. Storage 13.2
4. Expert mode settings
a. Re-bulk offset 0.4
b. Recondition voltage Disabled
c. Recondition stop time fixed
d. Recondition duration 0
e. Rail current Disabled
f. Temp compensation disabled
g. Low temp cut-0ff disabled
Areas where you could reduce cost:
- The obvious one, less batteries. I would still recommend a high-capacity battery but depending on your needs and ability to avoid running the AC, you could get by with less.
- Cheaper batteries. The Epoch's are very well made, are heated, have many high ends specs and are priced very competitively with other high-end batteries, but there are definitely cheaper options. There are several areas where I overspent in an effort to be extra safe. The Epoch Elites have a built in 500-amp fuse that I particularly liked. If you look at my schematic, I probably went overboard with fuses, but there is a lot of current involved and I feel good about the extra protection. I have the V1s which have some software glitches, and the firmware is VERY frustratingly NOT updateable. They are now selling the V2s, and I understand they have fixed some things, and the firmware is now updateable. The Epoch Elites are also advertised to have the ability to communicate with the Victron Energy Cerbo GX and when shopping that seemed like a nice bonus. While that is technically true, IMO it provides no value. I actually had all the comms hooked up and decided to remove them. It was way more trouble than it was worth and Victron alone provides everything you need.
- Don't use Victron. Victron Energy has no desire to be the budget friendly brand, and it shows. There are other options, but honestly, I didn't give them much of a look. You'll see people who are all in on Victron and tout the benefits being called "Smurfs" on some forums because everything Victron is blue. Victron makes pretty much every single piece you need to build a complete electric system from batteries, inverters and solar to fuses, busbars, AC distribution panels and automatic transfer switches. I'm sure if you were building something from the ground up and went full Smurf on it that it would all work beautifully together. It would cost a literal fortune, but I'm sure it would work well. Reading about all the Victron capabilities in the forums I was looking forward to electrical nirvana and bought a lot of blue. It all works together...kinda. There is absolutely some value in going all with the same brand, but not to the point where you should pay much more or give up any functionality. For example, I like that I can connect to every Victron device from the same app on my phone and the menu structure is mostly the same. (Note that Victron devices that have Smart in the name mean they have Bluetooth capabilities, it doesn't have anything to do with the devices actual capabilities) However, the DC-to-DC charges don't communicate with each other, much less the Cerbo GX (central hub). Same for the Blue Smart charger. You can get an output from these devices in the Cerbo GX, but it's buried a few screens deep. The devices all have Bluetooth and send data to your phone so you would think they could communicate with each other via Bluetooth. Nope. They all have to be wired to the Cerbo with Victron Specific cables. None of the devices come with the cables and they don't all use the same type. Frustrating. So, with all that said, would I go with Victron again? Probably. It's the de facto RV lithium brand. You could make any brand work, but if you want to be able to go online and search a question and have 50 forum answers come up, then Victron is your brand.
- Fewer SmartShunts. Think of the SmartShunt as a flow meter that tells you how much energy is flowing through a wire. You technically don't even need one at all. They simply provide you more information about the state of the batteries' charge and how the energy is flowing. The Outback inverters and DC to DC charges both can charge and maintain the batteries completely independently based on the voltage they detect in the batteries. I have three SmartShunts in my system. One is the primary and measures all current into and out of the batteries and reports the state of charge of the lithiums. It also has an auxiliary connection to the chassis batteries which reports their state of charge, but not energy flow. The second shunt detects the energy flow out of the DC-to-DC chargers while driving and the third detects the flow from the Outback chargers while charging and to them Outbacks while inverting. I would highly recommend the primary shunt, and it's required to get any meaningful information out of the Cerbo GX, but the other two are nice to haves.
- Skip the Victron Energy GX Touch 70, Display. All information you can see on the display is available via the phone app. This is a nice touchscreen that connects to the Cerbo GX and lets you see all the information and make configuration changes. I had envisioned this being mounted inside the coach, but that turned out to be more work than it would be worth. I ended up mounting mine in the battery bay and I really like having it there for a quick check and it was tremendously helpful during the setup, configuration and testing. At a minimum though, the smaller and cheaper GX Touch 50 would have been all that I needed.
- Fewer or no DC-to-DC chargers. The batteries I have can be charged at up to 100 amps. So, I could technically have 2 of the DC-to-DC chargers per battery for a total of 8. It's just a matter of how much you want to charge while driving. If you never or rarely plan to stay overnight without hookups, you could skip them entirely and just charge at your next stop. We regularly boondock one night while traveling between destinations and I wanted the batteries to recover from that night while driving in case we ever wanted/needed to do two nights. There are options for higher output DC-to-DC chargers, but the cost per capacity is about the same and I decided I would rather have the cost and reliability spread across multiple devices as well as have the ability to add capacity as needed. I originally ordered three charges and added the fourth later.
Parts list:
I have provided Amazon links just for the ease of showing the items I used. While I did purchase a lot from Amazon, I highly recommend shopping around and checking the Amazon Renewed store. Two of the places I had good luck with were:
Hodges Marine
The Yacht Rigger
Major hardware:
4 x 12V 460Ah V1 Elite Series lithium batteries (1,840 Ah total)
12V 460Ah V2 Elite Series - Heated & Bluetooth & Victron Comms LiFePO4 Battery
4 x Victron Energy Orion XS Smart DC to DC Battery Charger 12/12 50A
Amazon.com: Victron Energy Orion XS Smart DC to DC Battery Charger 12/12 50A...
3 x Victron Energy SmartShunt IP65 Battery Monitor
Amazon.com: Victron Energy SmartShunt IP65 Battery Monitor (Bluetooth) -...
1 x Victron Energy Cerbo GX MK2
Amazon.com: Victron Energy Cerbo GX MK2 : Automotive
1 x Victron Energy GX Touch 70, Display
Amazon.com: Victron Energy GX Touch 70, Display Screen for Cerbo GX (Waterpro...
Not related to lithium upgrade, maintains chassis batteries:
1 x Victron Energy Blue Smart IP22 Smart Car Battery Charger 12V 15A
Amazon.com: Victron Energy Blue Smart IP22 Smart Car Battery Charger 12V...
Installation parts:
3 x Victron VE.Direct Cable - 1.8M
Amazon.com: Victron Energy VE.Direct Cable, 5.90 ft : Automotive
40ft X 6 AWG Black cable + 40ft X 6 AWG Red cable
Amazon.com: 6 Gauge 6 AWG 40 Feet Black + 40 Feet Red Welding Battery Pure...
8 x Victron Energy Modular fuse holder for MEGA-fuse
Amazon.com: Victron Energy Modular fuse holder for MEGA-fuse : Tools & Home...
2 x Victron Energy Busbar to Connect 5 Modular Fuse Holder for MEGA-Fuse
Amazon.com: Victron Energy Busbar to Connect 5 Modular Fuse Holder for...
2 x Victron Energy MEGA-Fuse 100A/32V (Pack of 5)
Amazon.com: Victron Energy MEGA-Fuse 100A/32V (Pack of 5) : Automotive
4 x Blue Sea 5191 Terminal Fuse Block 30-300AMP
Blue Sea Systems 5191 Fuse Block Terminal 30-300 AMP: Battery Terminal Fuse:...
6 x Blue Sea 5189 250A Fuse Terminal (2 extra)
Amazon.com: Blue Sea 5189 250A Fuse Terminal DC Main Circuit Protection for...
1 x BUS bars: BEP Pro Installer Link Bar 35.5 - 42.5mm *5-Pack
https://www.amazon.com/gp/product/B095FVPZNV
1 x BUS bar: BEP Pro Installer Link Joiner 3-Way (two would have been better for the shunts)
https://www.amazon.com/gp/product/B00TUNHW90
2 x BUS bar: BEP Pro Installer 3 Stud Bus Bar - 650A
https://www.amazon.com/gp/product/B01J0JYY6W
Various size battery cable lugs
https://www.amazon.com/dp/B073FCNB9W
https://www.amazon.com/dp/B0CS6LF7DT
https://www.amazon.com/dp/B0CS6MZRLC
https://www.amazon.com/dp/B0CS6M3GFZ
Bep Emergency Parallel Switch - 12/24v - 500a (BEP720-MDO-EP)
https://www.amazon.com/gp/product/B0184S2MK0
Tools:
16T Hydraulic Crimping Tool
https://www.amazon.com/dp/B0BCFG9BFS
14in Hardened Cable Cutters
https://www.amazon.com/gp/product/B0CX1VWHZ6
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Topic: Lithium Conversion - 2014 IH-45