Auxillary Alternator with Nations/Wakespeed/REC-BMS

[VanGoSki]

For my build I've decided on 400AH of LifePo4 charged primarily by an auxiliary alternator. No solar. I'm using the Nations 280A, 12V aux alternator for N62 bracket, and a Wakespeed WS500 voltage regulator. The Wakespeed regulator package is a new option from Nations. It's supposed to be superior in that it tightly integrates with the BMS over CANbus. My battery is a DIY LifePo4 setup using Fortune cells. I'm starting with 8 cells for 200 AH, but will be upgrading with 8 more cells once I get this up and running.

The heart of the system is a REC-ACTIVE BMS which monitors SOC parameters, voltage and temperature, and charge regulation information which it sends to the Wakespeed voltage regulator via CANbus. The Wakespeed is configured as a battery-master configuration which delegates the battery monitoring and charge control the BMS. The BMS also drives master contactor that disconnects the battery from charging and loads if there are any problems, after first coordinating with the Wakespeed regulator to shut down the alternator. That should eliminate at least some of the load dump issues.

This is seems like a pretty elaborate system (at least to me), but I'm told the high level communications between the regulator and BMS solves a lot of issues and works really well.

I assembled most of the parts, but haven't drawn a schematic yet which I probably should soon. Here's my pile of parts laid out to show the rough configuration.

Some notes:

1) The BMS controls charging by sending messages over CANbus to the Wakespeed regulator. The Wakespeed is configured as a slave to the BMS

2) Single Contactor controlled by the BMS disconnects both the battery from charge and loads during an irregularities, coordinating with the voltage regulator connected to the alternator.

3) The BMS provides monitoring via bluetooth. However, I feel I should probably add a separate battery monitor. Maybe the Victron? And if so, can it use the same shunt as the BMS?

4) The REC-BMS is supposed to be able to communicate with the Victron inverter/charger as well via the CANbus. But it remains to be seen if this will work with the BMS talking to the regulator as well.

Comments are welcome. I may or may not be able to answer questions. I'm new to RV/van electrical systems and am probably in over my head at this point, but I'll eventually figure it out.

 

[TooMuchHair]

VanGoSki, we only have one 3500 mile trip in so far using the WakeSpeed 500 regulator and our 160 amp 48 volt alternator. Very impressed so far.
My EE son helps me extensively with programming of these systems, programming is one step (at least) above my pay grade, But here is what I think is correct. To get full functionality and to be able to use just one shunt via CAN to all of the system will require adding one of Victron's control GX devices, I have the Venus that I plan to use with an iPad Pro, but they now have the Cerbo which has an optional color touch screen if you prefer a stand alone display.
Next, there is a little more to insuring the alternator won't be damaged if your REC BMS (I have Tesla S modules so chose the SIMP BMS) calls for the contactor to open but don't feel quite able to explain it yet because we have not added the contactors yet. Which brings me to add that I think you actually need two contactors for absolute protection and safety. As I understand it they are current directional and can weld closed if trying to open in the incorrect path.
In case you aren't already following Juan & Michelle, this is a pretty good overview of your BMS.

 

[VanGoSki]

@TooMuchHair
Thanks so much for chiming in on my thread. I'm really jazzed that you've got one of these systems up and running and are willing to share your knowledge. Lucky you for having a EE son to help you with this. I have some knowledge of electronics, but these RV electrical systems are a science unto themselves.

Regarding monitoring. I do have the BMS bluetooth dongle and app which I assumed would be adequate for monitoring, but that may be a bit naive. We shall see. Otherwise I expect there will be a Victron monitor in my future.

Al assured me the single contactor will work fine with the REC-bms. It shuts down the alternator before the opening the contactor so I'm told this will be OK. But we shall see. I don't understand the contactor contact welding issue, but I will keep my eyes open.

Thanks for the setup video, I'm going to watch it now.

Thanks again for your input.

 

[HarryN]

@TooMuchHair
Thanks so much for chiming in on my thread. I'm really jazzed that you've got one of these systems up and running and are willing to share your knowledge. Lucky you for having a EE son to help you with this. I have some knowledge of electronics, but these RV electrical systems are a science unto themselves.

Regarding monitoring. I do have the BMS bluetooth dongle and app which I assumed would be adequate for monitoring, but that may be a bit naive. We shall see. Otherwise I expect there will be a Victron monitor in my future.

Al assured me the single contactor will work fine with the REC-bms. It shuts down the alternator before the opening the contactor so I'm told this will be OK. But we shall see. I don't understand the contactor contact welding issue, but I will keep my eyes open.

Thanks for the setup video, I'm going to watch it now.

Thanks again for your input.

Basically if the battery disconnects when the alternator is getting heavy field current, there is a massive inductive spike.

If the contactor is the cause of this disconnect, the inductive spike comes through and everything welds, almost no matter the interrupt rating.

That is why the desired shut down sequence is to drop the field current, then do the contactor disconnect.

The wake speed makes managing this much easier than it used to be. Not trivial but reasonable.

 

[VanGoSki]

Basically if the battery disconnects when the alternator is getting heavy field current, there is a massive inductive spike.

If the contactor is the cause of this disconnect, the inductive spike comes through and everything welds, almost no matter the interrupt rating.

That is why the desired shut down sequence is to drop the field current, then do the contactor disconnect.

The wake speed makes managing this much easier than it used to be. Not trivial but reasonable.

Hi Harry. The Wakespeed in my configuration is slaved to the REC-BMS. Basically the Wakespeed makes very few decisions in my set up, everything is delegated to the BMS for monitoring and control. So if the BMS decides to open the contactor, it first communicates the news to the Wakespeed via CANbus messages so that it can ramp down the alternator. I believe I have the Wakespeed programmed correctly now and will be diving into the REC-BMS programming next.

 

[johnplyler]

Hi, I am using the Fortune 3.2V, 100Ah prismatic cells too! Have you been watching Will Prowse's YouTubes?

For my build I've decided on 400AH of LifePo4 charged primarily by an auxiliary alternator. No solar. I'm using the Nations 280A, 12V aux alternator for N62 bracket, and a Wakespeed WS500 voltage regulator. The Wakespeed regulator package is a new option from Nations. It's supposed to be superior in that it tightly integrates with the BMS over CANbus. My battery is a DIY LifePo4 setup using Fortune cells. I'm starting with 8 cells for 200 AH, but will be upgrading with 8 more cells once I get this up and running.

The heart of the system is a REC-ACTIVE BMS which monitors SOC parameters, voltage and temperature, and charge regulation information which it sends to the Wakespeed voltage regulator via CANbus. The Wakespeed is configured as a battery-master configuration which delegates the battery monitoring and charge control the BMS. The BMS also drives master contactor that disconnects the battery from charging and loads if there are any problems, after first coordinating with the Wakespeed regulator to shut down the alternator. That should eliminate at least some of the load dump issues.

This is seems like a pretty elaborate system (at least to me), but I'm told the high level communications between the regulator and BMS solves a lot of issues and works really well.

I assembled most of the parts, but haven't drawn a schematic yet which I probably should soon. Here's my pile of parts laid out to show the rough configuration.

Some notes:

1) The BMS controls charging by sending messages over CANbus to the Wakespeed regulator. The Wakespeed is configured as a slave to the BMS

2) Single Contactor controlled by the BMS disconnects both the battery from charge and loads during an irregularities, coordinating with the voltage regulator connected to the alternator.

3) The BMS provides monitoring via bluetooth. However, I feel I should probably add a separate battery monitor. Maybe the Victron? And if so, can it use the same shunt as the BMS?

4) The REC-BMS is supposed to be able to communicate with the Victron inverter/charger as well via the CANbus. But it remains to be seen if this will work with the BMS talking to the regulator as well.

Comments are welcome. I may or may not be able to answer questions. I'm new to RV/van electrical systems and am probably in over my head at this point, but I'll eventually figure it out.

 

[johnplyler]

Hi, I am using the same Fortune 3.2V, 100Ah prismatic cells too! Have you been watching Will Prowse's YouTubes? I have my raw cells, but nothing else. I still haven't decided whether to go with a 12v or 24 volt system. Looks like Nations only puts out either a 12 or 24 volt alternator, so guess the 48 volt system is moot! Was there any particular reason you went with 12 volts? and the Wakespeed regular rather than the Balmer?
You wouldn't happen to live near Raleigh, NC? It would be nice to find someone close by to bound ideas off of.

 

[VanGoSki]

@johnplyler Yes indeed, it was Will Prowse's video on these cells that got me interested in them. I love the build of them.

I was actually planning on going with 24V. But... I also wanted to use my factory N62 mounting bracket. Unfortunately Nations 24V alternators are all the 3 belt system which requires a major effort to install (remove/replace harmonic balancer, etc) and I just didn't want to go there. The single-belt (actually 2-belt) install is a piece of cake. Plus it has another advantage of making both of the Sprinter belts much easier to install than before the aux alternator. Granted that having the aux alternator probably means you have to replace the main fan belt more often, but at least it's easily done now.

On the Wakespeed, others will disagree but using the Balmer with lithium seems a bit kludgey to me. Everyone figures out different ways to deal with the corner case issues. I asked Adam Nations about it and he pushed me towards the Wakespeed/Rec-BMS setup, introduced me to the Wakespeed guys, etc. They convinced me that this solves all the issues and then some. There's not a lot of info out there on this stuff, so I have to figure out most of it by myself. Maybe I got sold a pile of goods, we shall see. Like the old timers used to say, "You can tell the pioneers by the arrows in their backs." LOL.

 

[VanGoSki]

Some pics.

Top balancing my 8 Fortune cells. This is 200 AH, and I'll eventually 8 more cells for a total of 400 AH. Cells are all wired in parallel for balancing and powered by a cheap 10A regulated supply.

After balancing, I hooked 'em up to make a 12V battery with 4 sets of parallel 2-cell pairs which are in turn wired in series. The bus bar configuration looks weird, but is correct!

Breadboarding the system on the dining room table. My Fortune 12V 200 AH battery bank, the REC-ABMS, and the Wakespeed regulator which will do nothing until I install this in the van and connect it to the Nations aux alternator. I also have a Victron 12/3000 inverter charger that I'm using in inverter mode only right now for load testing. This will give me the opportunity to get each of the components programmed and communicating.

This what the optional REC control panel that runs on a PC looks like. Pretty basic and pretty crude. They charge $110 extra for this, but of course you can't change settings without it. Grr.

Notice I'm actually doing some fault testing with those settings. I have the max cell voltage set to 3V, but the cells are in the 3.4V range. This triggers an overcharge error. If you look carefully, you can see the REC-BMS which is that little box on the right. There are two leds on, one red and one green. The green one constantly flashes when the BMS is running. The red one is an error indicator that is actually flashing a code. In this case it's flashing just once about every second which is the error code for over voltage which is error 1. It will flash two times then a short pause and repeat for error 2, etc, up to 16 different codes. Another thing you can't tell from the picture is that the BMS is also beeping when an error is present.

I was told I only need one contactor in this system which handled both charge and discharge. This didn't sound logical to me, but I figured I try it their way and see if it made sense later. This test showed that the contactor opens to stop charging which is good, but it also kills my loads which is bad. So it still doesn't make sense and I've got a message into REC to see if they can explain how this is supposed to work. I think it's pretty clear I'm going to need to add a separate contactor for my loads which is what I'd guessed all along.

Here's the framework for the wheel-well cabinet which will house all this stuff.

Yes, I suck at welding. Getting better though.

 

[MountainVAN]

Some pics.

Top balancing my 8 Fortune cells. This is 200 AH, and I'll eventually 8 more cells for a total of 400 AH. Cells are all wired in parallel for balancing and powered by a cheap 10A regulated supply.

After balancing, I hooked 'em up to make a 12V battery with 4 sets of parallel 2-cell pairs which are in turn wired in series. The bus bar configuration looks weird, but is correct!

Breadboarding the system on the dining room table. My Fortune 12V 200 AH battery bank, the REC-ABMS, and the Wakespeed regulator which will do nothing until I install this in the van and connect it to the Nations aux alternator. I also have a Victron 12/3000 inverter charger that I'm using in inverter mode only right now for load testing. This will give me the opportunity to get each of the components programmed and communicating.

This what the optional REC control panel that runs on a PC looks like. Pretty basic and pretty crude. They charge $110 extra for this, but of course you can't change settings without it. Grr.

Notice I'm actually doing some fault testing with those settings. I have the max cell voltage set to 3V, but the cells are in the 3.4V range. This triggers an overcharge error. If you look carefully, you can see the REC-BMS which is that little box on the right. There are two leds on, one red and one green. The green one constantly flashes when the BMS is running. The red one is an error indicator that is actually flashing a code. In this case it's flashing just once about every second which is the error code for over voltage which is error 1. It will flash two times then a short pause and repeat for error 2, etc, up to 16 different codes. Another thing you can't tell from the picture is that the BMS is also beeping when an error is present.

I was told I only need one contactor in this system which handled both charge and discharge. This didn't sound logical to me, but I figured I try it their way and see if it made sense later. This test showed that the contactor opens to stop charging which is good, but it also kills my loads which is bad. So it still doesn't make sense and I've got a message into REC to see if they can explain how this is supposed to work. I think it's pretty clear I'm going to need to add a separate contactor for my loads which is what I'd guessed all along.

Here's the framework for the wheel-well cabinet which will house all this stuff.

Yes, I suck at welding. Getting better though.

Nice setup, I'm planing to weld out my own as well. what 48v alternator are you using?

 

[VanGoSki]

Nice setup, I'm planing to weld out my own as well. what 48v alternator are you using?

Thanks, the square tubing is 1", thin wall. Surprisingly light. The 1/2" plywood I'm planning on covering it with will be a lot heavier than the steel oddly enough.

I think you have me confused with @TooMuchHair though. His system is 48V, mine is 12V.

 

[johnplyler]

@johnplyler Yes indeed, it was Will Prowse's video on these cells that got me interested in them. I love the build of them.

I was actually planning on going with 24V. But... I also wanted to use my factory N62 mounting bracket. Unfortunately Nations 24V alternators are all the 3 belt system which requires a major effort to install (remove/replace harmonic balancer, etc) and I just didn't want to go there. The single-belt (actually 2-belt) install is a piece of cake. Plus it has another advantage of making both of the Sprinter belts much easier to install than before the aux alternator. Granted that having the aux alternator probably means you have to replace the main fan belt more often, but at least it's easily done now.

On the Wakespeed, others will disagree but using the Balmer with lithium seems a bit kludgey to me. Everyone figures out different ways to deal with the corner case issues. I asked Adam Nations about it and he pushed me towards the Wakespeed/Rec-BMS setup, introduced me to the Wakespeed guys, etc. They convinced me that this solves all the issues and then some. There's not a lot of info out there on this stuff, so I have to figure out most of it by myself. Maybe I got sold a pile of goods, we shall see. Like the old timers used to say, "You can tell the pioneers by the arrows in their backs." LOL.

@johnplyler Yes indeed, it was Will Prowse's video on these cells that got me interested in them. I love the build of them.

I was actually planning on going with 24V. But... I also wanted to use my factory N62 mounting bracket. Unfortunately Nations 24V alternators are all the 3 belt system which requires a major effort to install (remove/replace harmonic balancer, etc) and I just didn't want to go there. The single-belt (actually 2-belt) install is a piece of cake. Plus it has another advantage of making both of the Sprinter belts much easier to install than before the aux alternator. Granted that having the aux alternator probably means you have to replace the main fan belt more often, but at least it's easily done now.

On the Wakespeed, others will disagree but using the Balmer with lithium seems a bit kludgey to me. Everyone figures out different ways to deal with the corner case issues. I asked Adam Nations about it and he pushed me towards the Wakespeed/Rec-BMS setup, introduced me to the Wakespeed guys, etc. They convinced me that this solves all the issues and then some. There's not a lot of info out there on this stuff, so I have to figure out most of it by myself. Maybe I got sold a pile of goods, we shall see. Like the old timers used to say, "You can tell the pioneers by the arrows in their backs." LOL.

Thanks so much, you probably just saved me several days of research! Guess I will go with the same 12 volt system too from Nations. Keeping it 12 volts will make everything much simpler. I just got a MIG welder to weld up my stuff as well. I am hoping for everything in aluminum, we will see once I get the helmet on??? I was thinking about a wooden box for my batteries, but then I see all this about keeping them not too cool and not too hot. Since venting the battery will not be an issue, I am thinking of using an expanded metal aluminum box (with a very insulated top). I plan to treat my van garage just like the cabin as far as the HVAC goes, (68-72) degrees I am wondering if I shouldn't put rubber washers between the individual cells for even more ventilation. I just got my Espar hydronic heater, my setup will be like adventurevantastic and Wranglerstar and Humble Road's, combined. I plan to weld up my own expansion box and forgo the one from Rixens for $600. I also plan to put the espar in a aluminm box under the chassis like the 18-wheelers. I do hope my welding is good since I hope to save another $3000 on the roof top rack and rear door box! A lot dreams, we will see now that the weather is cooling off. You didn't say, but guess you don't live near Raleigh? Keep in touch, I would like to throw more ideas at you like planning a shower at my sliding door so I can have one, but not waste the space! johnplyler@gmail.com

 

[VanGoSki]

Ha, it actually took me several days to sort out the 12V vs 24 issues with Nations. I'm still not clear why they won't package the 24V alternator with the N62 kit. They really push the 3-belt kits, so it may be about maximizing profit. Or it may be because the 24V alternator stresses the belts more, although I don't see why it should.

My MIG is an old Craigslist find, and can't be fitted with a spool gun for AL. So I'm all steel which so far seems fine. I won't be building expansion tanks, so kudos to you for taking that on.

I don't think you want to space your cells out. The Fortune cells already have spacing built-in. Plus you'll screw up your bus-bar spacing unless you make flexible ones like @Midwestdrifter . I am planning on first connecting the cells together with threaded rod, and then building a box for them with mini-cell foam between the cells and the box.

I'm in the CA Bay Area, so couldn't be further from NC. Plus this is my first van build and I don't know squat, so probably won't be able to help out much with most topics. But this forum is awesome for information exchange and full of super-knowledgeable and friendly people. It will be fun to track each other's progress.

 

[Midwestdrifter]

Belt stress is a function of output watts. The 24V alternators are often capable of higher wattage output, so there may be belt limitations in play. Due to the small drive pulley alternators need to achieve higher RPM on diesel engines, they are limited by the serp belts contact area in that case.

As a note many (most?) aluminum cased cells have the case connected to the positive terminal. So its possible to create short circuits if metal objects break through the insulation film on the case.

 

[VanGoSki]

Belt stress is a function of output watts. The 24V alternators are often capable of higher wattage output, so there may be belt limitations in play. Due to the small drive pulley alternators need to achieve higher RPM on diesel engines, they are limited by the serp belts contact area in that case.

Thanks for chiming in, MWD. The 24V alternator is 150 amps, while the 12V alternator is 280 amps. So pretty close, really.

As a note many (most?) aluminum cased cells have the case connected to the positive terminal. So its possible to create short circuits if metal objects break through the insulation film on the case.

Holy crap, that's good to know!

 

[TooMuchHair]

Ha, it actually took me several days to sort out the 12V vs 24 issues with Nations. I'm still not clear why they won't package the 24V alternator with the N62 kit. They really push the 3-belt kits, so it may be about maximizing profit. Or it may be because the 24V alternator stresses the belts more, although I don't see why it should.

My MIG is an old Craigslist find, and can't be fitted with a spool gun for AL. So I'm all steel which so far seems fine. I won't be building expansion tanks, so kudos to you for taking that on.

I don't think you want to space your cells out. The Fortune cells already have spacing built-in. Plus you'll screw up your bus-bar spacing unless you make flexible ones like @Midwestdrifter . I am planning on first connecting the cells together with threaded rod, and then building a box for them with mini-cell foam between the cells and the box.

I'm in the CA Bay Area, so couldn't be further from NC. Plus this is my first van build and I don't know squat, so probably won't be able to help out much with most topics. But this forum is awesome for information exchange and full of super-knowledgeable and friendly people. It will be fun to track each other's progress.

In regard to why Nations "really push the 3-belt kits". As briefly as possible, Adam Nations stood behind countless issues with the N62 MB mounted alternators primarily installed by Roadtrek before they went out of business. Roadtrek was an early adopter for the bigger, lithium based electric systems. The MB N62 designed aux drive system's weakest point (their are several) is the limited amount of "belt wrap" on the drive pulley on the crankshaft, it works fine until you approach it's limits as experienced with high watt output alternators. All of a sudden you are faced with advanced belt wear and issues related to minor misalignment causing problems, and unfortunately when this belt breaks or throws off you can very quickly overheat. Likely resulting in the need for a tow. I can already hear the guys that are pleased with their N62 setups.....and it is fine until you ask too much from it. (Just like virtually any mechanical design.)
The third belt drive (my choice from a different vendor, only because Nations lacks a 48VDC alternator) design provides a significantly increased amount of belt wrap and the ability to withstand the demands of driving these higher output alternators reliably. It was a fairly significant project to install, and required ordering a flywheel locking tool to be able to properly remove and re-torque the crankshaft/balancer bolt to 280 ft.lbs., but it really seems like a bulletproof solution.
I just wanted to add a little of what I have learned since being found laying underneath one of Roadtrek's first Etreks at the Hershey PA RV show in 2013....they told me that I wasn't allowed to look....but I had time to grab a picture of the "Nations" alternator. And that was the beginning of years of paying attention and focus of my research. I can tell you for certain, that Adam Nations seems like a great guy! He took care of so many issues that RT had in those early years...sometimes even overnighting parts to stranded RVers.

 

[VanGoSki]

@TooMuchHair Thanks! Good to know the background. Sounds like those of us with the N62 should probably keep the output in the conservative range. Lots of members here have good mileage on the N62 kits with no issues.

There should be no reason for a tow if the belt breaks though if you carry a spare, as it's actually easier to replace than the stock belt. With the stock set up you need to pull off the fan to install a new belt because it's a smaller diameter than the fan. But since the new belt for the N62 is longer, it can fit around the fan. There are two wires that need to be R&R on the fan hub, but that appears pretty easy. As a bonus the inner main fan belt on the Sprinter can now be changed easily as well as it was that short front belt that made replacing it difficult as well. Just carry spare belts and a couple of tools.

As an aside, anyone know what those two wires on the fan hub do? Some kind of sensor I'm assuming, but one of the wires is pretty fat.

 

[gltrimble]

@TooMuchHair As an aside, anyone know what those two wires on the fan hub do? Some kind of sensor I'm assuming, but one of the wires is pretty fat.

The “fat wire” is actually a coolant line. Do you have the part number for the second rear belt?

 

[VanGoSki]

The “fat wire” is actually a coolant line. Do you have the part number for the second rear belt?

No sorry I don't. I'm pretty sure I learned everything I know about this from you actually.

Are there any caveats or issues with disconnecting that little coolant line? I'm pretty much ready to install my aux alternator.

 

[gltrimble]

Are there any caveats or issues with disconnecting that little coolant line? I'm pretty much ready to install my aux alternator.

No caveats. I think I just plugged the end of the coolant line with a pencil or pen while replacing the belt. A very large screwdriver was helpful in leveraging the new belt over the tensioner pulley.