Arco Zeus Alternator Regulator Bench Test

[Mal Reynolds]

Originally Posted by Starrider

...I used a separate shunt in the negative lead of the wire that goes to the engine block. The other side of this shunt goes to the load side of the Victron battery shunt. This shunt is connected to the Zeus battery shunt wires. This shunt will report the current coming from the alternator without having to install a shunt in the positive lead of the alternator. ...Will be installing the new LiFePO4 batteries this week and will update this post with photos to make this more clear.

Starrider, I'm following this thread carefully, but struggled a bit to follow your description of your solution above.

Maybe a diagram?

[Starrider]

Will take photos this weekend and label the shunts and wiring.

[Acadia]

This is an interesting and new way of wiring the Zeus and works fine but has a potential caveat. For clarification did you do this to avoid having to place a shunt on the positive side. Or just to wait till the Victron Coms are active ?

The whole intent of having the alternator shunt with the Zeus was to have alternator output available net of all other sources. By wiring it the way you did the Zeus will no longer be able to protect your batteries from too much current, this will become very important when you have lithium. You also can’t take advantage of the tail current (not a big deal in most cases). Also very important to have the voltage sense wires close to the batteries.

Once Victron Coms are established and you can read battery shunt data are you going to move the Alternator shunt sense wires to the negative side shunt you installed? You will lose alternator voltage but that is less important. At this point you will have your battery shunt info and your alternator shunt info.

It all depends on your system design. What I mean by all of this is the ability of the Zeus to limit your charge current. Say you have 2 lithium batteries that have a recommended charge current of 100amps each. With a 250 amp alternator and some solar kicking in you could easily exceed that. This is what the max charge current setting is for in the Zeus app. Zeus can’t control the other charge source but it will certainly adjust its output to maintain that limit. This requires the battery shunt.

If your total net charge capabilities are less than your battery maximum then I suppose you are fine. Otherwise could lead to issues you are not expecting.

[Starrider]

Acadia,
Way back in January, spoke to Nick on the phone about my installation. Assumed before talking to him that the Zeus regulated alternator output current by using the alternator shunt in the positive lead of the alternator. It does not use that shunt for regulating the output current, it actually uses the BATTERY shunt to regulate alternator output current. That is why in the instructions it says the alternator shunt is OPTIONAL. All the alternator shunt does is give you a display of alternator current in the app, not needed for the Zeus to function. To verify this please watch the bench test video I posted in the beginning of this thread.

So by adding a separate shunt in the engines main negative lead connected to the Zeus battery shunt sensor leads (which will measure alternator output current, glow plug and starter draw) have the ability to measure alternator output current without an alternator shunt. As stated before this was done so the the Zeus will not get skewed results if the Zeus used the Victron shunt. If the Zeus was connected to my Victron shunt it would be reading alternator output current AND the current being generated by my boats 600 watts of solar and 800 watts of wind.

So you are incorrect about the Zeus not protecting my batteries, it actually uses the shunt I added for that purpose, same as if it used the Victron shunt for the battery monitor. The whole reason the Zeus was installed is to limit alternator charging current to the new LiFePO4 batteries that will be installed tomorrow.

Agreed, very important to have battery voltage sense right at the battery terminals. My system is wired this way and the Victron battery monitor sends this information via Bluetooth to the Victron solar charger to account for any possible voltage drop between the solar charger and batteries.

Have no intentions of using Victron wired communications. My new LiFePO4 batteries do not have Victron communications and no intention of using a Cerbo. Between the Victron battery monitor and the monitor for the Victron solar charger that is all I need to keep tabs on the system. The Victron Battery monitor will keep tabs on charging current from Solar and regulate that as necessary and the Zeus will have charging current and voltage information and regulate that as necessary. With proper programming battery charge current and voltage will not exceed the parameters for the batteries.

Hopefully this made the installation more clear in your mind, and if you have any more questions will be happy to answer them. Thank You for your input.

[Alden]

Hi Starrider.

Let me see if I can paraphrase your description, to check my understanding.

1. You have a Victron shunt at battery negative. The Zeus does not sense any information from this.

2. You have a shunt on the alternator negative cable (AKA engine negative), which provides the Zeus with the output of your case grounded alternator. You program the Zeus to manage this current.

3. The Zeus senses voltage from the battery terminals.

4. You program your solar charger (a Victron MPPT?) to limit this current flow. Same for a wind charger if installed.

5. You are satisfied that maximum current flows at various points in the system are acceptable, whether discrete or combined.

6. It works. You are the DVCC.

Is this a fair summary? :-)

[Pete7]

Originally Posted by Starrider

2. Alternator Charging. Yes, folks are still recommending keeping an outdated expensive, heavy AGM battery on board as your start battery. Then to make it worse you have to add a DC to DC converter to that start battery and add more wiring, switches, fuses etc. to charge your new LiFePO4 batteries. Oh, the DC to DC charger now limits your alternator charging to 30 amps unless you want to add 2 of them (more expense and wiring). Short of spending over $1,100 for a Balmar alternator and regulator, these were the only ways to deal with it.

Folks, there is an easier way. Purchased this Alternator regulator. https://arcomarine.com/products/arco...ator-regulator Expensive but found a dealer that sells it for $225.00 cheaper.
This will allow you to use your current alternator (with a simple modification) to charge your new LiFePO4 batteries.
Throw away the AGM battery, DC to DC converter and wiring and use KISS (Keep It Simple Stupid). New LiFePO4 batteries now have the current to start our tiny engine. Leave the battery switch to the all position and you have hundreds of cranking amps available to start your Westerbeke.

Hope this helps someone.

So let me get this right, you are suggesting I ditch a perfectly good AGM starter battery, plus my Victron Smart Orion and buy a $500 widget instead. I will also need a Victron shunt and perhaps a Cerbo GX to monitor all this and the blue box to control it. What will that cost me, the thick end of $2000 perhaps? and doesn't solve the problem of a single point of failure.

If I wanted a simple alternator controller with temperature monitoring, I would probably buy the cheaper Sterling equivalent. Doesn't have a BT shunt, but by the time you get to this point you probably have one anyway.

So thank you, but I will stick with what I have, because alternator charging is a secondary source of power averaging just 10% of our needs. Solar providing 90% according to my stats. It would be much cheaper to add more solar.

Pete

[Starrider]

Hello Alden,

Yes, that pretty much sums it up.

It works because the boat has a very small alternator 50 Amp mitsubishi modified to use an external field and limited to 40 Amp max output. Zeus also set up to use rpm and temperature feedback. The Zeus is mainly used to prevent the small alternator from destroying itself with the battery load.

All this equipment was set up on my test bench working together to see if it was viable. Only issue that was found if a load on the system was removed (like shutting off a non Victron inverter) with the batteries at 100% charge, the Victron MPPT would sometimes have a delay and overshoot the 14.4 bulk it was set for. It appears it was such a short time (seconds) that the batteries BMS charge MOS which disconnects at 14.7 never noticed. Never occurred during float.

Again, with each charge source programmed correctly they will all play well together. If each device did not have the programmability they do, it would not work. Had to upgrade all charge sources as the former equipment was not liFePo4 compatible.

And will agree for the average person without an electronics background, a Cerbo system would be the best fit for them.

Originally Posted by Alden

Hi Starrider.

Let me see if I can paraphrase your description, to check my understanding.

1. You have a Victron shunt at battery negative. The Zeus does not sense any information from this.

2. You have a shunt on the alternator negative cable (AKA engine negative), which provides the Zeus with the output of your case grounded alternator. You program the Zeus to manage this current.

3. The Zeus senses voltage from the battery terminals.

4. You program your solar charger (a Victron MPPT?) to limit this current flow. Same for a wind charger if installed.

5. You are satisfied that maximum current flows at various points in the system are acceptable, whether discrete or combined.

6. It works. You are the DVCC.

Is this a fair summary? :-)

[Alden]

Originally Posted by Pete7

Solar providing 90% according to my stats. It would be much cheaper to add more solar.

Pete

Hi Pete.

Solar is great, but at times and in places it doesn't cut it, i.e., very high latitudes in summer, or where lots of people live in cloudy, rainy winters. Or any night-time.

I've just worked on a design for a second alternator that will add 3200W of charging to 1200W of solar. Yay! Now, whenever the engine is running, the batteries will be filled.

[Starrider]

Hi Pete

In my case the 3 AGM batteries were at their end of life. If a new agm was purchased, could only fit 2 new liFePo4 batteries. The 3 new liFePo4 batteries are 105 AH each (24 case). The 3 of them together have more capacity then the 3 AGM's, so much more it is like having a 4th AGM in the system in the same space.

I could not see replacing an AGM starter battery every 5 years and the loss of capacity keeping it in the system. Or adding a DC to DC converter.

To each their own. Just like you, solar and wind does the heavy lifting. Was considering just giving up on the alternator completely. But that alternator is very handy at night, with no wind and running radar!

Not using a Cerbo or suggesting one in my case. Each charge source has its own "brain" and works independently so there is my redundancy.

The cost of the Zeus was cheaper then a new alternator and controller. Was cheaper than purchasing a new AGM (that would only last 5 years) along with a DC/DC converter.

Originally Posted by Pete7

So let me get this right, you are suggesting I ditch a perfectly good AGM starter battery, plus my Victron Smart Orion and buy a $500 widget instead. I will also need a Victron shunt and perhaps a Cerbo GX to monitor all this and the blue box to control it. What will that cost me, the thick end of $2000 perhaps? and doesn't solve the problem of a single point of failure.

If I wanted a simple alternator controller with temperature monitoring, I would probably buy the cheaper Sterling equivalent. Doesn't have a BT shunt, but by the time you get to this point you probably have one anyway.

So thank you, but I will stick with what I have, because alternator charging is a secondary source of power averaging just 10% of our needs. Solar providing 90% according to my stats. It would be much cheaper to add more solar.

Pete

[Starrider]

Here is a photo of how a shunt was added to my system to allow the Zeus to measure alternator current only, in the negative lead. It will also measure starter and glow plug current also.

Starting in the bottom photo is the shunt added for the Zeus. The skinny red and yellow wires go back to the Zeus and connect to the battery shunt wires. The wire circled in red is the negative wire going back to the engine bell housing, since the alternator is grounded to this wire, alternator current is available here to measure.

The terminal circled in blue feeds the negative bus for boat circuits and is daisy chained to the Victron shunt at the top of the photo.

The terminal circled in yellow is the Victron Shunt and goes to the negative terminal of all 3 batteries.

The terminal circled in orange is the load side of the Victron shunt. It is feeding a 3,000 watt inverter and is daisy chained back to the shunt added for the Zeus.

In this configuration the Victron battery monitor can see all current going in and out of the batteries from all charging or loads (Including the current from the alternator). The added shunt at the bottom measures alternator charge current or loads from the engine such as glow plugs, starter current, etc.

Hope this helps!

[s/v Jedi]

So how does the Zeus prevent damage to the alternator rectifier diodes during a battery HVC event?

[Starrider]

Originally Posted by s/v Jedi

So how does the Zeus prevent damage to the alternator rectifier diodes during a battery HVC event?

What do you mean by HVC?

[s/v Jedi]

Originally Posted by Starrider

What do you mean by HVC?

Huh? It’s one of the crucial functions of a BMS and the reason alternator charging of LFP can result in damaged rectifier diodes. It stand for High Coltage Cutoff.

[Starrider]

Threw me for a loop, it is normally called HVD High Voltage Disconnect.

The Zeus is fully programmable and can be adjusted in voltage and current output. Properly programmed, it will never allow the the BMS to reach high voltage cutoff.

Old school lithium batteries have changed. Modern batteries now have fail-safe's that prevent the battery from shutting off if the BMS senses high voltage. Some batteries, including some name brands and cheapies on amazon do not have this technology.

Modern batteries (and the ones I chose) shut off the charging Mosfet in the battery during a HV event. I know this sounds impossible (and I tested it) the battery can shut off cell charging in the BMS yet still put out power and support loads. The alternator will not even be aware the charging mosfet shut off charging at the cell level, because the battery is still outputting power and supplying loads on your boat.

I used to rebuild alternators for a living (among other things) and well aware that if loads are disconnected from modern alternators the diodes and internal voltage regulators will be damaged.

Hey, I am so fricking old, can remember in the 60's disconnecting the battery from a running car to see if the Generator was charging (note the word generator) . Do that today and you will blow half the electronics in the car!

Just followed the link to your sailing page, that is one beautiful Yacht you own. Remember drooling over that yacht in cruising world and sailing magazine, enjoy!

Originally Posted by s/v Jedi

Huh? It’s one of the crucial functions of a BMS and the reason alternator charging of LFP can result in damaged rectifier diodes. It stand for High Coltage Cutoff.

[eheffa]

Originally Posted by Starrider

Here is a photo of how a shunt was added to my system to allow the Zeus to measure alternator current only, in the negative lead. It will also measure starter and glow plug current also.

Starting in the bottom photo is the shunt added for the Zeus. The skinny red and yellow wires go back to the Zeus and connect to the battery shunt wires. The wire circled in red is the negative wire going back to the engine bell housing, since the alternator is grounded to this wire, alternator current is available here to measure.

The terminal circled in blue feeds the negative bus for boat circuits and is daisy chained to the Victron shunt at the top of the photo.

The terminal circled in yellow is the Victron Shunt and goes to the negative terminal of all 3 batteries.

The terminal circled in orange is the load side of the Victron shunt. It is feeding a 3,000 watt inverter and is daisy chained back to the shunt added for the Zeus.

In this configuration the Victron battery monitor can see all current going in and out of the batteries from all charging or loads (Including the current from the alternator). The added shunt at the bottom measures alternator charge current or loads from the engine such as glow plugs, starter current, etc.

Hope this helps!

Hi Starrider,

This is quite helpful. Thanks.

I am considering upgrading my alternator controller to a Zeus in order to charge our new 960 Ah LFP house bank. (2 x 460Ah Epoch's that are actually showing capacity of 480 Ah each.)

I have a 160 Amp alternator with a rather old-tech Balmar MC-612 External regulator. I have two Victron Orion-Tr 30A DC-DC chargers in place to charge the LFP while running the main engine but would prefer to exploit more of the alternator's capacity and charge the LFP bank directly from the alternator whilst still ensuring I don't overload the alternator. The DC-DC chargers can be repurposed to charge the AGM start and thruster banks.

We do have a Victron BMV shunt in place to monitor battery voltage and SOC.

I understand that I could install a Cerbo GX and connect the Zeus and the Epoch's to the Victron system but I am not convinced that I need to do that if I could get the Zeus to see the true voltage and SOC being reported by the Victron BMV. (It does make sense to have the extra shunt to monitor alternator output.)

Is there a way to integrate the Victron shunt without going to the Cerbo GX and DVCC?