Public Discussion Forum

I'm debating whether I should replace my old Balmar MC624 regulator with a new Zeus regulator and would like some feedback from those who have. For now I would keep my Balmar 220A alternator. Specific questions are:

1. Are you happy with it overall?
2. Do you also have a Zeus alternator?
3. Where did you locate the regulator?
4. Did you get the longer harness or shorter one? Did you extend it?
5. Did you install the alternator shunt?
6. Did you integrate that into the Victron ecosystem?

Very interested in getting your feedback.

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

Richard,

I sell and install many Zeus regulators. They are excellent. After working with a Zeus the Balmar MC624 seems like it is made for cave men.

I personally do not have a Zeus alternator (because boat already had big large case Balmar) but we have used them and they are also excellent. The heat shedding capability on their small case units is among the best we have seen other than alternators with the rectifier diodes remote.

In most cases I buy the Zeus part number (AZ1000X) that has the long 30ft alternator harness. This way the regualtor can be installed nicely at some appropriate location well off the motor. THere is no reason to have it hanging on the motor or adjacent where subject to heat/vibration and in the way of maintenance. The balmar regulator on mine was on a plate mounted to the engine block. Hot, vibrating, subject to fluids, in the way of wrenching.

Yes it shoudl be installed with alternator shunt especially if you are putting it into a Victron ecosystem which works very nicely.

There literally is no downside. It is such an upgrade especially if you are doing all your energy management with a Cerbo GX. Adding the Zeus just brings it into the fold as far as intelligent charge management/visibility.

I would keep your Balmar alternator and upgrade to the Zeus (this is exactly what I did when I did my Victron system.)

Hi Greg,

On the alternator side we replaced our Balmar large case with an Arco 4403 alternator 24V 4kW LTO DF4, Side Battery Post, Isolated Ground on our John Deere. We’ve been extremely pleased with the performance. We are still using the Balmar M624 external regulator as this was brand new, replaced after it destroyed the Balmar alternator!

Brgds

Phil Davies

Asante 5334

Hi Greg,

At survey we had a squeak on the alternator, initial thought was belt needed tightening, but after checking it was determined that alternator was overheating and bearings failing. Mechanic changed out to our spare, all appeared good and engine rpm increased, at which point alternator overheated and seized. Had an electrician onboard who diagnosed failing M624, we replaced. Balmar alternators were obsolete and had to be sent to West Coast for rebuild, we elected to go with the Arco, no regrets so far.

Phil Davies

Asante 5334

Greg,

I did not mean to make a marketing post. I am participating here as a individual Selene owner with certain experience gained from running a service compnay. I do deal with the alternators as well and can try to offer any information/assistance on that.

The 24v Arco alternator is great. Arco has hundreds in service and they seem to be doing well. They sell a "LTO" version as well that gives higher output at low RPM. The QSL9 is a slow turning torque monster so this may be a good application for the LTO version but of course pulley size can make the alternator turn faster as well. My QSL9 has a "large case" Balmar 95-series 24v/140a. The pulley ratio on mine is currently 2.9. I think the original OEM Cummins pulley ratio was 2.7. We would ahve to look at spec sheets and pulley options to dial in alternator RPM to optimize either the regular or LTO version.

There is an argument to consider keeping a workhorse heavy duty large case alternator vs. a high strung, high output small case like the Arco. For example I can probably pump 100a all day all night from the large case 140a alternator without it breaking a sweat. The Arco 24v is rated at 284a peak, 220a sustained but can you really get that without some kind of dedicated forced air cooling? The good news is that paired with the excellent regulator we just take either alternator to 95C or maybe 100C if you want to push it and output is regulated by alternator temp.

Most of the time if a trawler motor is started it is going ot run a while (hours). We don't use alternators like some of our sailboat friends without a genset who have to run the alternator for primary charging and want as fast as possible during that first hour or two of run time.

What alternator is there now?

I bought and installed (with the help of a marine electrician) an Arco Zeus regulator. I have a Balmar 98 series 220A @ 24V high output alternator.

I'm having problems with the install. Bottom line is the alternator is not producing power. The regulator is faulting for "ignition". I get my ignition source from the fuel pump. My multimeter says the voltage is 15.4VDC =/-0.05 - very stable. When I move the ignition wire to the positive post on the alternator (essentially the battery voltage

~ 27VDC) I don't have the ignition fault, but the regulator does a soft ramp until about 50% field and then I get an "tachometer" fault. The batteries were mostly charged, so I'll redo the test with low batteries. I'm not sure why I can't use the fuel pump as the ignition source.

Also, the bluetooth signal is so low that I have to be within 3 feet to get a connection.

Can anyone shed some light on what might be causing this? I talked to Arco, but I felt that I knew more than they did, so I need to get in touch with a more experienced person. Trying to get this resolved and go to the BAHAMAS!

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

Hi, Richard.

I have a Zeus and have had a love/hate relationship with it. We pair it with a Balmar Series 96 100a 48v alternator, which ran fine the summer of 2024. When we started cruising last year something caused (with think a voltage spike from the Zeus) to fry the alternator. Bit of a scary moment. Arco stepped up and sent (free of charge) their 48v alternator, which I will say is a beast. The attached screenshot from the app shows it putting out 121.1a @ 55.3v with the alternator field pegged back to 80%. We thought we were good to go, but we experienced various errors on our Raymarine MFD, particularly intermittent AIS and GPS errors/dropouts. The Zeus is tied into the NMEA 2000 network and not the Victron CAN. If I disable the Victron follower mode in the Zeus app and disconnect the NMEA 2000 connection, the system runs like a champ. When I get back to the boat later this month, I plan to try a few suggestions from the ARCO Zeus High Energy Community Facebook group. I suggest you post your issue to the group and see what you get back.

(2) ARCO Zeus High Energy Community | Facebook

Thank you Nick. I got on FB and put out a message. Within a few hours I got several good responses. The most helpful was a troubleshooting checklist. I was finally able to get the reg/alt working. This is what I found:

1. I didn't realize I had to change the "Sync Mode" to "Victron GX (N2K)"
2. For some reason, the Zeus didn't like my 15.4VDC ignition signal. It was fine with 24v (the native voltage). I am going to install a 12-24v converter.

After fixing those 2 things, the Zeus was working well. At my pokey 1250 rpm I was getting 130A @ 24V charging the batteries. Nothing worse than cruising all day and arriving to your anchorage with low batteries.

Now, if I can only figure out why my get home engine decided it didn't want to start....

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered

Good to hear you got it sorted. How are you connecting to your Victron system? Are you using the Zeus Canbus port or the NMEA 2000 port? If Canbus, are you connecting into your Cerbo? I'm connected via NMEA 2000 and I'd like to try the Canbus route, but I'm not sure where I have an open RJ45 port. I think one of my batteries has a Victron terminator in a port, but I'm not sure I can use it for this purpose.

Also, what is your pulley ratio for your alternator? My ratio is not optimal (smaller) because the installer used a dual v-belt configuration. At some point, I'd like to get a smaller pulley for the alternator and add a tensioner to get the RPMs up. It runs a bit hot and derates, so I'm not getting as much power and cooling as I could with a higher ratio.

Thanks!

Nick Vespa

LunaSea 5318

Nick,

I have the Zeus plugged into the VE.Can network through the RJ45 plug (with a resistor on the NMEA2000 port). You can daisy-chain the VE.Can, so mine is coming from a Skyllar charger. The network is connected to the Cerbo. The alternator shows on the Cerbo UI as another source with the voltage, charge current, etc. It's pretty sweet.

My pulley ration is about 1.9, not as good as I'd like. The prior owner(s) left smaller alternator pulleys and I might try them if I don't get enough charge out of the alternator. However, in a brief test I was getting about 130A at my cruising RPM of 1250. I'll take that! I considered getting the Arco alternator, but my Balmar 98 series is a beast and really well built. It uses 2 5/8" Vee belts, and the Arco used 2 1/2" Vee belts. Finding a driver pulley for my Cummins QSM11 isn't an easy task, so I'm going to resist fixing something that isn't broken this time.

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

Mark, my thinking is similar to yours. I do have a 24V boat, so I have no clue why the voltage on the fuel pump solenoid is 15.4V, but more on that later. I talked to Arco's technical support and they said there is a wide range of working voltages for the ignition source (like under 12VDC to 80VDC - something like that).

I did use a 24V battery source for the ignition signal and the regulator worked. I also bought a 12 - 24V converter to bump up the ignition signal from 15.4 to 24V and that DIDN'T work. ??? I did a little more digging and found that when I connect my Zeus' ignition lead onto the fuel pump solenoid the voltage drops from 15.4 to about 3. Strange. I thought there might be a bad wire or connection so I put a jumper right on the solenoid post to the ignition wire on the Zeus harness and got the same result. I need to find a better source for my ignition signal that is more stable, AND find out why my fuel pump solenoid voltage is only 15.4 and why it drops when a small load is attached.

Also, the tach signal is coming from my alternator's stator. The Balmar manual says, "Unrectified AC voltage can be used as a signal for an electric tachometer." But in my case the tach signal is not stable. It will work intermittently and take the regulator out of charge mode. That's not a big problem since I can turn off the "Tach Required" switch in the Zeus app.

So for now to get off the dock I can manually place a jumper to get a good 24V signal for the ignition, but I need to find a better source for the ignition signal that turns on with the ignition key.

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

*** UPDATE ***

I just asked ChatGPT why my fuel pump solenoid voltage would be 15.4V on a 24V system and this is what it said,

"Many modern Cummins electronic engines don’t feed actuators with straight battery voltage. The ECM (or an engine interface/relay module) may pulse-width modulate or current-limit the solenoid.

• A typical handheld DMM reads the average of that pulsed waveform, and the “average” can easily land around 12–18 V even though the peak is near 24 V.
• 15.4 V is a very believable “average” reading for a PWM signal, especially during certain states (run, prime, shutdown, etc.).

I was "assuming" (you know what that makes me) that the alternator's ignition signal has been attached to this fuel pump post since before I bought the boat that it was a good source. However, I've been having problems charging since owning the boat and historical records show a problem existed before me. I solved at least 2 other issues related to the regulator, but this may be ANOTHER issue to deal with.

I can't tell you how many long term issues I've solved on this boat. Many like this which were very subtle or hidden. I'll circle back to this post when I can confirm that the fuel pump isn't a good ignition source and what a better source would be.

I keep telling my wife Kelly that this boat isn't a Toyota. We could take the Toyota into the dealership and get it fixed. Boats are a totally different animal.

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

Ryan,

The solid red wire is connected to a 12V panel that is powered by a 24V to 12V converter.

The red with black tracer is connected to the alternator + which is 24V.

The problem is the ignition wire. I had it connected to what I thought was a fuel pump solenoid, but it is a pulse width modulated fuel pump control. Whoever originally installed the Balmar alternator/regulator had it wired this way, and the alternator has behaved unusual for as long as I've owned the boat (5 years). I just need to find a better 12-24V ignition source.

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

Mark, I have Hynautics controls, so no electricity involved. I'll trace down the signal from the key switch to the ECM and plug in there. Strange, I looked through the Cummins manual for a electrical drawing and didn't find one. They had a diagram for every other system, but not electrical. I never let that stop me.

Richard Nye

Untethered, 57-22

https://forecast.predictwind.com/tracking/display/MV_Untethered/

Did you get this sorted, Richard? I saw your last post on Facebook to the Arco group, but didn't see any responses.

Nick

LunaSea 5318