Foretravel Owners' Forum

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 (https://www.hodgesmarine.com/)
The Yacht Rigger (https://theyachtrigger.com/)


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 (https://www.epochbatteries.com/products/12v-460ah-lifepo4-battery-ip67-heated-bluetooth-victron-comms)
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... (https://www.amazon.com/Generic-DC-DC-Charger-Victron-ORI121217040/dp/B0CWYWQGBF)
3 x Victron Energy SmartShunt IP65 Battery Monitor
   Amazon.com: Victron Energy SmartShunt IP65 Battery Monitor (Bluetooth) -... (https://www.amazon.com/Victron-Energy-SmartShunt-Battery-Bluetooth/dp/B0BF636VBX)
1 x Victron Energy Cerbo GX MK2
   Amazon.com: Victron Energy Cerbo GX MK2 : Automotive (https://www.amazon.com/gp/product/B0D6LVZWGX)
1 x Victron Energy GX Touch 70, Display
   Amazon.com: Victron Energy GX Touch 70, Display Screen for Cerbo GX (Waterpro... (https://www.amazon.com/dp/B0B613GD16)

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... (https://www.amazon.com/dp/B08TRP71QM)

Installation parts:
3 x Victron VE.Direct Cable - 1.8M
   Amazon.com: Victron Energy VE.Direct Cable, 5.90 ft : Automotive (https://www.amazon.com/gp/product/B01CPWVTS2)
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... (https://www.amazon.com/dp/B01MUC7888)
8 x Victron Energy Modular fuse holder for MEGA-fuse
   Amazon.com: Victron Energy Modular fuse holder for MEGA-fuse : Tools & Home... (https://www.amazon.com/gp/product/B01M1GPA06)
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... (https://www.amazon.com/gp/product/B01LXW5WIN)
2 x Victron Energy MEGA-Fuse 100A/32V (Pack of 5)
   Amazon.com: Victron Energy MEGA-Fuse 100A/32V (Pack of 5) : Automotive (https://www.amazon.com/gp/product/B06X3XGHTS)
4 x Blue Sea 5191 Terminal Fuse Block 30-300AMP
   Blue Sea Systems 5191 Fuse Block Terminal 30-300 AMP: Battery Terminal Fuse:... (https://www.amazon.com/gp/product/B0019ZBTV4)
6 x Blue Sea 5189 250A Fuse Terminal (2 extra)
   Amazon.com: Blue Sea 5189 250A Fuse Terminal DC Main Circuit Protection for... (https://www.amazon.com/gp/product/B005E47HG2)
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

Thank you Ted. Your parts list is super helpful. Looks like you've put an incredible amount of energy into designing and building this set up. I'm sure you will enjoy the final product.
Michael

I only have 3 460 Epoch Essential batteries. While at Quartsite this year with refrigerator and heat I would go from 100% to 75-85% overnight.  I used the original Foretravel cables and it turns out the black cables were the same length, but for some reason they had different resistance. I have not had time to figure out why yet. The difference in resistance I believe caused the different batteries to discharge at different rates,  thus one at 75%, 85%, and one somewhere in the middle. When changing they would change at different rates to all end up at 100% around the same time. 

I don't have DC-DC Chargers. The most I have seen the 3 batteries take on alternator was around 170 amps for a short time.

Lithium batteries in parallel when charging and discharging at low rates will go out of sync. This has to do with the BMS switching the outputs based on load.  For low current charging applications, they even charge in steps, one at a time. Don't go crazy trying to fix this. This why for parallel applications you want as few batteries as possible to meet the demand and why 4 is the recommended limit. This becomes more of a factor for serial sets as the BMS has to support the current load. Balancing is much more important and often external balancing is sometimes needed. Back to parallel the occasional full charge cycles will reset the batteries. For multi battery applications I recommend using the external shunt meter and only viewing the built in BMS display for occasional maintenance and trouble shooting.  Generally, for the multi battery sets I don't even get them with the built in Bluetooth unless the customer requests. Sometimes just too much information.

Ted

Very nice setup. I have a comment and a question.

Load on alternator

You stated that 200 amps would be well within the capacity of the 340 amp alternator. Alternators aren't designed for continuous current at the maximum rating. Typically the alternator maximum rating should be de-rated 75% for continuous current applications. 75% of 340 amps would be 255 amps. Running down the road I'm thinking the coach alone would need say 100 amps for engine and tranny electronics, headlights, wipers, dash fans, etc. This puts you at 300 amps or more for possible continuous current.

A Delco 55SI 430 amp alternator de-rated is 320 amps which would give you some margin.

Stacking shunts

Depending on the current load from either of the "secondary" shunts, there will be a varying small positive voltage bias at the high side of the "primary" shunt instead of being at battery negative 0 volts. Could this small voltage bias introduce an error in the readings of the "secondary" shunts?

Might be a question for Victron. Does their documentation discuss stacking shunts?

The manufacture of our 340 amp alternator is no longer in business. I have talked to a guy that makes similar alternators and knew the people that made ours. I asked him what he thought the duty cycle was for the alternator since I have not seen any literature for the unit. He said that the alternator that we have is used on fire trucks and ambulances and he felt that they could handle whatever load is thrown at them for an extended time.  Our coaches will run the second AC unit off the inverter and alternator. I have run the AC unit off just the inverter and load was around 145 amps. While not our coach Tom and I checked to see how many amps were being used by his coach while we were at Quartzsite this year. We came up with around 25 amps.  This number did not include running lights, fans, or running lights. From what I understand the 50 amp units he is using can be adjusted to limit the number of amps used.

Note there are three alternators.
blob:chrome-untrusted://image-magnify/7f874699-c2f8-4713-8787-e90fee957ae3
https://1drv.ms/i/c/9b02084a888884a6/EZAXplnLfiZNv_VifZyHipcB9E4fBSBBK1sXZLZZIC0IEA?e=haDG0Q

And look at the size of the AC compressor.

Dennis

Interesting photo, is this your coach? In the IH-45 brochures I don't see any reference to more than one alternator. Is this a custom setup?

In Ted's pictorial diagram there is one alternator shown.

Yes, not discounting what your friend is saying but alternator spec sheets don't have continuous duty specs. Rather than speculating, testing should be done to verify results.

Most modern alternators have thermal protection that will reduce current when hot. With lower voltage the DC-DC chargers will self-adjust and draw even more current which is a vicious cycle that could damage an undersized alternator.

While I haven't measured the actual engine load, I would guess that it wouldn't be anywhere near 100 amps.  Just guessing I would have started somewhere around 20-30 amps and that sounds close to what Turbojack saw on a different coach. Headlights and dash fans would be the main draws I can think of.  I would guess the engine and other chassis components would be in the single digit amps.  All the big stuff is driven off of the engine belt.  Just as a thought exercise, how long would you expect to be able to drive the coach if the alternator died completely?  The OEM chassis batteries have a combined 300-amp hours.  I have no idea, but I know you can go a long way in a car.

Here is the math I was using:  340 * .75 = 255 amps available, so even if all four DC/DC chargers are maxed out, that leaves 55 amps available.

Another bit of info that I hadn't shared, I spoke with a gentleman that used to work at KEI, the manufacturer of my alternator, and he enthusiastically assured be I had nothing to worry about.  He said the published spec on the alternator was low and they regularly saw significantly higher numbers on bench testing.  You can take that with a grain of salt, but I feel like I'm safe.  The next time I've been driving and charging for an extended period of time I'll try to remember to stop and grab a temperature reading off of the alternator.  That would be very good to know, and I'll share here when I do.

I don't know that I am 100% following your question, but if you're suggesting the secondary shunts might not be 100% accurate, that may be, but it's nothing to worry about.  Those shunts are just there to give me an idea where the current is flowing to or from.  The secondary shunts are in what is called DC meter mode, so they are measuring the flow of energy and not the state of charge at all.  After I am a little more comfortable with the operation of the DC/DC chargers I may move that shunt to measure the current going to the 12V DC loads so I could see usage by AC (inverter) and 12V loads.  They are purely informational.
As for Victron, most of their documentation is pretty light, but section 3.7 of the attached manual covers the DC meter usage and shows 1 additional shunt.

These coaches are power hungry!  I was shocked out how much current was being used just sitting idle.  The refrigerator, heat and the auxiliary air pump are the big draws for me.  Starlink, the original satellite dish and many other things have a constant draw.  Even my awning has small continuous pull, no idea why.

Did you confirm, or just suspect, that the cables have different resistance?  That doesn't sound right at all.  I would inspect the cable ends and connections, it would be very bizarre for the actual cable to have a difference.

What would be really interesting for your new setup would be a way to monitor alternator current while driving. This might work:

Amazon.com: DROK 12V 48V Battery Meter, Energy Efficient LCD Display Marine... (https://a.co/d/fYo1xYg)

If the alternator dies you can start the genny and inverter and hit the boost switch to charge all batteries. I've heard of people driving across the US that way to get home.

All I need is another shunt.  :-)

Of course, you need to be sure all those DC-to-DC converters get disabled when that boost solenoid is used to back feed the chassis-alternator system.
As for current draw when the alternator can't keep up and the voltage drops they can just keep drawing more current to get the set output voltage to the alternator. 50 amps at 14.6 volts = 730 watts. If the alternator drops to 13.6 volts, they can pull almost 54 amps plus a bit more for losses.

I thought of that, but shunts need to be in the current path to ground which you wouldn't be able to do unless you have an isolated alternator with a negative terminal.

I believe that this alternator also has a ground wire connected to it.

The alternator may have a dedicated ground but there are also ground paths through the engine and other ground connections.
The reason that the sensing shunts get installed on the ground side is because the shunt itself is exposed for cooling, and it would be a hazard to have that exposed conductive block on the positive connections. If you can address that it can be used on the positive side and work the same way. Another option is to use an inductive type meter.
For testing clamp on ammeter type multimeters are readily available and reasonably priced. You should have one with all your stuff anyway. You could then test the alternator output with a variety of load conditions and then you will know how to manage all those loads.

Dennis, yes I agree a shunt could be used.

I installed a ring current sensor in a SUV camper conversion I did with my daughter. Cheap, quick, easy and very cool to see what the alternator is doing - voltage and current. Of interest to me was alternator output at idle so she can charge while camping. We put a smaller pulley on the alternator that increased the idle output significantly.

And the need for the smaller pulley is an indication that the alternator is working near max output. And they should be able to do that.
In some ways even for lithium the simple relay control for charging house batteries is best. When the alternator cannot keep up such as happens with higher loads or at low speeds both the house and chassis batteries are available to help. With lithium there is the added advantage that since they are at a higher voltage, ~13.6 fully charged they can actually prevent the 12.6 volt chassis batteries from discharging.

I think you missed the part about wanting to increase the output at idle. 

Nope, didn't miss the output at idle. Are you sure you are not over speeding it now at max RPM?
The size of the pulley, alternator RPM was not an accidental calculation.
And yes, I would do the same if needed. 

I apologize for another long post, but you all got me thinking.  This afternoon I performed some very unscientific test and as a result I believe I have actually lightened the load on my alternator, not increased it.  Here are my findings and calculations and I look forward to your comments.

A couple of notes.  The ambient temperature was 44, so relatively cool.  High idle on the engine is ~900 RPMs, so not nearly the ~1600 you would see driving.  I calculated that the alternator produces ~240 amps at high idle vs ~330 while driving.  With the additional capacity and increased cooling while driving, I would expect the temperatures to be lower at all load levels from what I observed.  I did not record the decimal in my amp readings, so in some cases the individual numbers do not add up exactly to the whole.  I could get temperature readings that were considerably different on different parts of the alternator.  I don't know if this was a true difference or related to the surface or the angle of the reading.  I simple choose one of the spots and read that same spot each time.  I used a Klein CL800 to measure amps and a Flir TG267 for the temps.

I started the coach, with everything on the dash, the lithium batteries and all chargers off.  The only thing that I believe was using any current was the coach itself.  I put the engine at high idle and let it run for ten minutes.  After ten minutes I assume the starter batteries would be at 100%.  At this point I took these measurements:

Alternator temp: 102 - pic 1
Amps
Alternator output: 26
Load 1: 12 (Vehicle electronics)
Load 2: 13 (Engine plus batteries)
(see battery isolator pic for locations)

Turned dash fan and headlights on high and waited another 10 minutes:
Alternator temp: 102 - pic 2
Amps
Alternator output: 47
Load 1: 12 (Vehicle electronics)
Load 2: 35 (Engine plus batteries)

Turned on 1 Orion charger:
Alternator temp: (didn't measure)
Alternator total: 95  **(added 50 as expected)**
Load 1: 12 (Vehicle electronics)
Load 2: 84 (Engine plus 1 Orion charger)

Turned on all 4 Orion chargers:
Alternator temp: 139 - pic 3
Alternator total: 118  **(did not add 150 as expected)**
Load 1: 12 (Vehicle electronics)
Load 2: 106 (Engine plus 4 Orion chargers)

At this point I spent 20 minutes trying to figure out why I wasn't getting the full 200-amps of charge I expected.  Short answer, I had the Orion chargers configured wrong.  Long explanation at the bottom.

After 10 minutes of all 4 Orions at 50 amps:
Alternator temp: 210 - pic 4 through 8
Alternator total: 240
Load 1: 12 (Vehicle electronics)
Load 2: 232 (Engine plus 4 Orion chargers)


Using these measurements and some very rough estimates of house loads, here are my calculations for alternator load.

Max original alternator load:
Watts
1,700   AC
+ 600   Refrigerator
2,300 = AC load watts

+ 255   10% inverter inefficiency
2,555 = Watts of AC load

+ 300   Total 12v loads
2,855   Total house wattage = ~238 amps

Amps
238 = house loads
+47 = engine + dash fans and headlights on high
285 = total load on alternator


Max original alternator now:
Amps
200 = max load possible from house
+47 = engine + dash fans and headlights on high
247 = total load on alternator


With the Orions in place, the max load on the alternator appears to be lower.  Thoughts?


Long answer from above, the Orion chargers are smarter than I thought.  They are able to automatically detect when the engine has started based on the change in voltage of the starter battery.  This makes installation really simple since you don't need any kind of trigger wire to start the chargers.  I recently added the Blue Smart Charger as a battery maintainer for the chassis batteries when plugged in at a resort.  When it's charging the starter battery the voltage of course rises due to the charge current.  As a result, the Orios sensed the increased voltage and start pulling from the starter and charging the lithiums.  While technically not hurting anything, it kept a slow constant charge going on all batteries and was not what I wanted.  I thought I had found a solution by using a setting in the Orions called "Input voltage lockout" which is a hard cutoff for the voltage of the incoming starter battery.  If the starter battery drops below the cutoff, the chargers immediately stop charging.  I had my lockout set at 13.6 which was above the voltage when the charger was charging, but below the voltage when the alternator was charging.  However, what I didn't know is that the Orion's don't charge at max capacity until the voltage cutoff is tripped, they regulate themselves down as the cutoff gets closer.  So, if I raised the cutoff voltage the Orions would ration themselves down to only a few amps each and when I lowered it, they increased their output as there was additional buffer between actual voltage and the cutoff.  They will never actually be the cause of the current dropping below the cutoff.  It's a very very nice feature and I'm glad I understand it better.  My low voltage cutoff is now set at 12.7 volts.

Great job in finding this information.
In your calculations before upgrading, what about amps used to change the house batteries? Was the 300 Watts of 12v load battery charging?

The 300 watts was just a plug and not based on any measurements.  It would be inclusive of the house batteries charging, ALL 12V usage (lights, toilets, Aquahot pumps and fans, Firefly system, etc.) and anything additional plugged into 120v (laptop, Starlink, TVs, microwave, etc.).  I think 300 watts is probably extremely conservative and anything higher would only further support that the max load on the alternator has been reduced. If it weren't for the Orions, the alternator would be exposed to the full chassis and house loads PLUS a massive 920 max charge amps from the batteries.  If you wanted, you could reduce the load further by only installing 2 or 3 DC/DC.  In fact, if I'm ever driving in extreme heat, I'll likely turn the fourth one off.  At least in my case, the DC/DC chargers are protecting the batteries from overcharging as well as protecting the alternator from overloading.

When at Quartzsite with 3- 460 ah batteries at 75% the most i saw the batteries take was around  174 amps and that was for a very short time. I would say that they averaged around 40 amps per battery most of the time.  I have never gotten them down to 50% to see if that would have caused them to charge at a higher rate

Awesome testing.

It looks like you "could" have a situation where the Orions wouldn't keep up if you ran the A/C while driving:

Orions providing 200 amps - house load of 238 amps = -38 amps.

This additional current draw would be covered by the house batteries.

Also on turbojack's question about charging. I believe your "before" calculations left out possible charging of the house batteries. Let's say house batteries are at 60% after some dry camping and the driving starts and you need the A/C. During the time of charging the house batteries there could be a significant overload of the alternator.

I'll reiterate that I am not at all an expert on these things and please take my comments as intended to be helpful discussion, but I think you may have been maxing out your alternator and that was the limiting factor.

I'm making a few assumptions, that you were charging off of the alternator, you were using high idle and your equipment is similar to mine.
If so, that would mean your engine was at ~900 RPM and using a 3.36 ratio of drive pulley to alternator pulley (this is what mine has) that would mean the alternator was seeing 3,024 RPMs at the shaft.  From the attached alternator specs the alternator should have been putting at around 235-amps.

235    Total
-26    Load I measured with engine only
-174  going to batteries
35    amps remaining for ALL house loads plus 10% inverter losses

The only way to know for sure would be to take actual measurements.

Correct.  Absolute worst-case scenario, I could start the generator which would supply 100% of the AC load as well as help charge the batteries.

The only way for the house batteries to get power from the alternator is to go through the DC/DC chargers which can never pull more than 200-amps.

Yes, your new setup is very good for the alternator. I was just thinking about the "before" stock Foretravel setup. An unsuspecting owner could fry the alternator.

prfleming, ah, I see.  I misread that before.

I should have said while generator was running.  I also have 2 x Outback VFX2812M inverter/chargers for total of 250 amps but most I saw going in batteries was 174 amps for a short time.


Coach came with 6- 8D Gel batteries and I have put many miles on the coach with the second roof AC going on high. There were time that I would forget to turn the unit off when stopping and would not snap to it until I would step back in coach. I bet during those time the alternator was working overtime running roof AC and recharging the house batteries.

This picture was on the companies web site that build the alternator that is in Ted's and my coaches. Would you say that this alternator can run continues at 90%?  If so 90% of 340 = 306 amps

I was looking at the K.E.I web site (re-directs to Patriot Parts) and it appears they now are re-selling Dixie DelStar brushless alternators with their own part numbers.

Patriot Parts & Service (http://www.patriotpartsusa.com/)

DELSTAR - Heavy Duty Brushless Alternators (https://delstar-hd.com/)

Hmmm, I wouldn't design a system based on that. With alternators there is a lot of "specsmanship" going on.

The other thing with alternators is beware of the knock-offs. They say things like "replaces" or "compatible with". Another indicator is the cost is 1/2 of the genuine original.

An alternator failure 1000 miles from home is no fun.

This is a well thought out system and everything has been designed with plenty of reserve capacity.

Looking at the alternator heat pictures there is one at 247 degrees. It seems to me, the alternator is the weak link in this otherwise very robust system. Also the K.E.I. model you have is not the more reliable brushless design.

If it was me, as the last upgrade to bring everything up to snuff, I would go to a brushless Delco 430 amp or a DelStar 435 amp alternator. Add a 5th Orion and then have 250 amps to support the A/C, fridge, house loads with power to spare and the alternator will run cooler and last longer. Keep the K.E.I. as a spare.

Just looked on Amazon and price is $3,350.00 with 1 day shipping  for the Oem Delco 55Si Pad Mount Alternator  430 amps. In my case I think I will keep what I have.  I have been 1,350 miles from home and had a def head go bad that put me in 5 mph max derate right after it went south, don't know how a dead alternator could be any worse.  I will have to go and look again but I think the only thing on the alternator belt is the alternator.

So much going on here. I lost track of who is doing what.  I see a lot of over complication.
Anyone think to add another alternator? Really need that much battery-inverter power? Maybe 24 or 48 volt.
Many Prevost-Newels have 24 volt 500 amp alternators. 24 volt chassis electrical also common.
Some have 3 or 4 alternators.
The original Duvac-Diode set up already has significant current limitation to the house battery bank. That works very well with reasonable size lithium packs.
My 270 amp alternator-diode block is supporting a 900 A/H set just fine.

FindItParts on sale $2,241

Delco Remy 8600473 Alternator + Cross Reference | FinditParts (https://www.finditparts.com/products/2305084/delco-remy-8600473?srcid=CHL01SCL010-Npla-Dmdt-Gusa-Svbr-Mmuu-K2305084-L1503&pv2=eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJjIjoiVVNEIiwiZXhwIjoxNzQwNTIwNjQwLCJtIjoiNjc2Njc1NiIsIm8iOiIyMzA1MDg0IiwicCI6MjI0MS43NjAwMDAwMDAwMDAyfQ.wiKTkkBW07F8Q86RcEoRSmiOR6V6TwIbaHdFroZT3LuNJq41jLYcsSARBWxVeLe9SRKpVpWjdhxE2Jd9vl0WVQ&srcid=CHL01SCL010&utm_medium=cpc&utm_source=google&utm_marketing_tactic=broad&utm_paid_search_intent=vendor-brand&utm_campaign_id=21341868715&utm_ad_group_id=&utm_ad_id=&utm_platform=x&utm_placement=&utm_keyword=&utm_target_id=&utm_match_type=&utm_feed_item_id={feed_item_id}&utm_extension_id={extension_id}&utm_location_interst=&utm_location_physical=9193421&utm_product_id=2305084&gad_source=1&gclid=Cj0KCQiA8fW9BhC8ARIsACwHqYowunHIzovAQ-6wDdZrS-kJlu8C-g_-N0UfyKJ7C1WYXIdsuKIWxbUaArcOEALw_wcB)

Careful, that is a Rareelectrical knock-off, not genuine Delco.

I called Dixie DelStar, their competitive model for the Delco 55SI is a Series 180 100-18111 435 amp alternator.
Price quoted was $1583.33.

Ducted end cap is available to provide outside air much cooler than in the engine room.
 

This site is an awesome resource. Thank you for the post. 

Update on DelStar Series 180 100-18111 435 amp alternator. They are currently out of stock, new units scheduled to be available 4/18. You can order direct (bypass distributor) and have shipped from the factory in Canada.

Call Candice 905.......879.......0533.

Notes:
Confirm pad width of 80 mm on your existing alternator.
105 mm pad also is available
J-180 mount also is available

Curious what is the price for either the 275- or 340-amp alternator. I have a very simple set up. My inverter/charger has a 150 A/H charge section. With the 12K genny I really could add a second charger or inverter/charger combo. Treating my alternator nicely I could use the genny and the inverter charger to provide near 150 amps to the batteries adding to or reducing the alternator load and also running the AC or whatever at a cost of ~$4.00/hour.  That's 250 hours per $1,000 of upgrades for alternator battery charging. My 2008 generator is just under 1,270 hours.

Curious what is the price for either the 275- or 340-amp alternator. I have a very simple set up. My inverter/charger has a 150 A/H charge section. With the 12K genny I really could add a second charger or inverter/charger combo. Treating my alternator nicely I could use the genny and the inverter charger to provide near 150 amps to the batteries adding to or reducing the alternator load and also running the AC or whatever at a cost of ~$4.00/hour.  That's 250 hours per $1,000 of upgrades for alternator battery charging. My 2008 generator is just under 1,270 hours.

Give Candice a call, tell her Peter sent you  ^.^d

One thing I should mention regarding Delco and DelStar alternators. These are similar in that they are self-excited and do not have an excite terminal. This means they will not work with a standard diode isolator.

To use one of these alternators with an isolator the isolator must be replaced with one that has an "ignition" or "energize" terminal which will provide the required start up voltage to the alternator. Several forum members have done this when switching to a Delco alternator.

Here are links for a couple of isolators that will work with a Delco or DelStar alternator.

Amazon.com: Victron Energy Argofet Battery Isolators 200-2AC (2 Batteries... (https://a.co/d/hMSQxQy)

Sure Power 24023aIB Battery Isolator (https://www.ase-supply.com/Sure_Power_24023aIB_Battery_Isolator_p/sp-24023a-ib.htm)

These self-excited alternators will work in any system connected directly to batteries. In Ted's lithium system the alternator is connected directly to the start batteries so a self-excited alternator will work fine.

Here is the Delco bulletin that describes the isolator issue in more detail.

Note the current limitation of those isolators. Need larger or parallel.

There is a way to home brew your own excite circuit to use a standard diode isolator with a Delco alternator. My '91 used this technique as designed by Foretravel. This is how the isolators you can buy with the excite option do it. Here is my original '91 schematic.


20PCS 1N4002 Rectifier Diode 1A 100V DO-41 (DO-204AL) Axial 4002 1 Amp 100... (https://a.co/d/iOe9wIu)

Here is a 300 amp isolator that I used in my '91 when I put in a larger Delco alternator. I put 2 terminals in parallel for the house batteries.


Sure Power 3003 Battery Isolator (https://www.ase-supply.com/Sure_Power_3003_Battery_Isolator_p/sp-3003.htm)

2 battery version

Sure Power 3002 Battery isolator (https://www.ase-supply.com/Sure_Power_3002_Battery_isolator_p/sp-3002.htm)
 

While diode isolators offer some advantages for house battery systems, the larger ones are expensive and they have a significant power loss. In addition, having the alternators operate at a higher voltage to compensate increases the heat the needs to be dissipated in the alternator for a given delivered current.  For example, 14 volts at 250 amps = 3,500 watts. 15 volts at 250 amps = 3,750 watts. For the diode block itself voltage drop is almost a volt after it gets hot. Another 250 watts lost.

My go to is this Blue Sea ACR relay with override both electrical and mechanical.

ML-ACR Automatic Charging Relay with Manual Control - 12V DC 500A - Blue Sea... (https://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A)
This also eliminates the need for the boost relay.

Ted, have you gone back and checked to make sure what you set your Outback chargers to is still there and it did not go back to default?  Yesterday I was searching for air leaks with my tester. It does not like the sound that the Outbacks make when charging or inverting so I had disconnected from shorepower. When I reconnected I saw that the batteries were charging at 14.4V, I put my volt meter on a battery to verify the 14.4V.  I then went and checked the programing at the Mate2m and the programing was back at default.  I changed it back to 14.1 got back out of programing, went back in and the 14.1 value was still there.  Not sure why it went back to default.  Possible that Silverleaf did it but not sure. 

On second note have you thought about upping your charger limits to 15 or 16 instead of leaving at 14?  I believe that 16 will give you  125 amps per charger, where you (and I ) at 14 will only get around 110 amps per charger.