Arco Zeus alternator controller

[Tiger 1057]

I recently enquired with Roamer batteries regards their 230 ah 24v LifePo4 battery as I was considering changing my AGM batteries to Lithium.

As I have a  Mastervolt Alpha Pro external regulator for my 110ah Leece-Neville alternator i can't go down the Hybrid route as I understand it.

Steve Kennedy from Roamer batteries had said that with the use of a Victron Cerbo GX and either the Arco Zeus external regulator or the Wakespeed this would be feasible. Unfortunately they haven't tested this set up with the Alpha Pro so although he thought it may well work there may be limitations.

I initially dismissed the thought of the Arco Zeus but after I recovered from the shock of its price I started delving deeper and came across the thread on the forum started by @cheesegas and being honest I didn't really comprehend a lot of the posts as I don't have the mental capacity following a severe brain haemorrhage years ago  In fact to be fair I wasn't clever enough to understand them before the stroke.

I then saw a thread by @IanDwhere it was said that there were some issues with the device (Feb 25). I was wondering if this was still the case or have they been resolved?

I had read a post by @nicknormanwhich made reference to low engine revs. I have Gardener 3L2 which is low revving and wondered if this would be an issue for me?

@dmr also made a number of points regarding the controller and now I am in a world of pain trying to make sense of my dilemma.

I would be very grateful for people's views on the matter. Does the Arco Zeus now work as it should without bugs and would a slow revving Gardener be cause for concern?

I know @nicknormanand others are capable of making there own solutions and adaptations but I'm just looking for a plug and play set up as I wouldn't be able to resolve any issues that arise.

Many thanks 

[cheesegas]

3 minutes ago, Tiger 1057 said:

I would be very grateful for people's views on the matter. Does the Arco Zeus now work as it should without bugs and would a slow revving Gardener be cause for concern?

No reason for a slow revving Gardner to be of concern as long as you have the correct pulley drive ratio.

 

The Zeus is much better now than when I wrote the post a couple of years ago, but it's still far from perfect. Few issues with the current firmware are - 

 

Tacho input isn't very sensitive. I suspect this is a hardware issue. For the RPM sensing to work correctly on a smaller alternator, you need to have the minimum field drive up fairly high, around 15-20% on the three alternators I've tried. If there is nothing else on the boat drawing current, it may mean that once the battery is charged, the regulator is unable to hold the voltage constant as the minimum field % is too high. This will cause the voltage to rise until it trips itself on over voltage. 

 

Issue is with the Zeus, I've connected the alternator to a scope and electronic dashboard tacho with the field drive at 5-10%, both of which pick up a clean sine wave, enough for the dash tacho to work properly.

 

 

The other problem is there is a lot of damping applied to the inputs, or they're not sampled frequently enough. For example, if the output voltage rises very quickly, it could easily go up past the Zeus's upper limit - when it's supposed to trip and cut the field current - before it's registered the change. This means the BMS may do a high voltage disconnect before the Zeus realises the voltage has risen past the threshold.

[PeterF]

My Wakespeed WS500 running my Beta43 175A alternator has been in 18 months now, originally on AGM batteries, now Victron NG lithium batteries with a Victron Lynx BMS and Cerbo GX. I have had no problems with it, all reports from 3 years or so back about poor voltage regulation appear to have been solved. WS500, Multiplus inverter / charger and solar all play together nicely controlled by the BMS voltage and current requirements.

Edited April 8 by PeterF

[Tiger 1057]

Many thanks for that information. I hadn't actually looked into the Wakespeed but perhaps I should. It just seemed that it required more to set up. 

12 minutes ago, PeterF said:

My Wakespeed WS500 running my Beta43 175A alternator has been in 18 months now, originally on AGM batteries, now Victron NG lithium batteries with a Victron Lynx BMS and Cerbo GX. I have had no problems with it, all reports from 3 years or so back about poor voltage regulation appear to have been solved. WS500, Multiplus inverter / charger and solar all play together nicely controlled by the BMS voltage and current requirements.

 

1 hour ago, cheesegas said:

No reason for a slow revving Gardner to be of concern as long as you have the correct pulley drive ratio.

 

The Zeus is much better now than when I wrote the post a couple of years ago, but it's still far from perfect. Few issues with the current firmware are - 

 

Tacho input isn't very sensitive. I suspect this is a hardware issue. For the RPM sensing to work correctly on a smaller alternator, you need to have the minimum field drive up fairly high, around 15-20% on the three alternators I've tried. If there is nothing else on the boat drawing current, it may mean that once the battery is charged, the regulator is unable to hold the voltage constant as the minimum field % is too high. This will cause the voltage to rise until it trips itself on over voltage. 

 

Issue is with the Zeus, I've connected the alternator to a scope and electronic dashboard tacho with the field drive at 5-10%, both of which pick up a clean sine wave, enough for the dash tacho to work properly.

 

 

The other problem is there is a lot of damping applied to the inputs, or they're not sampled frequently enough. For example, if the output voltage rises very quickly, it could easily go up past the Zeus's upper limit - when it's supposed to trip and cut the field current - before it's registered the change. This means the BMS may do a high voltage disconnect before the Zeus realises the voltage has risen past the threshold.

Thank you so much for the update on the device. Do you know if anyone has engineered a solution to the field current problem?

[cheesegas]

1 minute ago, Tiger 1057 said:

Many thanks for that information. I hadn't actually looked into the Wakespeed but perhaps I should. It just seemed that it required more to set up. 

 

Thank you so much for the update on the device. Do you know if anyone has engineered a solution to the field current problem?

I don't think there's a solution to the field current problem. It's a thing you need to watch out for on all external regulators which rely on the alternator for speed sensing, but the input being not that sensitive makes it more of an issue. Also, the Wakespeed manual has a warning about the minimum field being too high but the sparse Zeus manual doesn't mention it.

 

The workaround is to use something else for speed sensing; my old Isuzu has a Hall sensor on the camshaft which is designed for use with certain dash tachs. The Zeus isn't sensitive enough to pick it up, but I'm working on a bit of simple circuitry which should make it possible. It's also possible to mount a generic magnetic pickup near the crank pulley to get RPM data into the regulator.

 

The original Wakespeed WS500 is definitely more fiddly to set up than the Zeus, but the new Pro version with Bluetooth is much much easier now.

[Tiger 1057]

10 minutes ago, cheesegas said:

I don't think there's a solution to the field current problem. It's a thing you need to watch out for on all external regulators which rely on the alternator for speed sensing, but the input being not that sensitive makes it more of an issue. Also, the Wakespeed manual has a warning about the minimum field being too high but the sparse Zeus manual doesn't mention it.

 

The workaround is to use something else for speed sensing; my old Isuzu has a Hall sensor on the camshaft which is designed for use with certain dash tachs. The Zeus isn't sensitive enough to pick it up, but I'm working on a bit of simple circuitry which should make it possible. It's also possible to mount a generic magnetic pickup near the crank pulley to get RPM data into the regulator.

 

The original Wakespeed WS500 is definitely more fiddly to set up than the Zeus, but the new Pro version with Bluetooth is much much easier now.

Thank you.  Very interesting and from what you say I would have thought that Arco would have been on top of that with a solution.

[PeterF]

As Cheesegas says, the Bluetooth version is easier. I have the older version,  but what has made a huge difference is the Android app for programming the WS500 makes it much easier. I have no idea if the app works on iPhone for the older USB version  but should be OK on Bluetooth, but would need checking. Prior to the app, Wakespeed programming was very clunky.

I have just had a look at my data through the Cerbo GX. I have no minimum field set and when the WS500 is producing no current with a field drive close to 0% the WS500 is still reliably reporting alternator (and engine) rpm from the domestic alternator close to that from the engine alternator. The field drive is only reported as whole numbers so 0% could be 0.4999%.

Edited April 8 by PeterF

[nicknorman]

The low rpm issue was just about having a large alternator connected to a relatively short stroke modern engine - at low engine rpm the maximum available torque is quite low. This was not a problem introduced by an alternator controller, it was a feature of how Beta set up the pulley ratios, although made worse by Li batteries which can take the alternator's maximum current for long periods. But both the Zeus and the Wakespeed have a setting that causes the maximum field current to be reduced at low rpm to avoid the problem. I would have thought that a Gardner would not suffer from this problem so much, since it has a lot of torque at low rpm, and it was not about the absolute rpm anyway, it was about how much torque as a proportion of the maximum, is available near idle rpm.

1 hour ago, cheesegas said:

I don't think there's a solution to the field current problem. It's a thing you need to watch out for on all external regulators which rely on the alternator for speed sensing, but the input being not that sensitive makes it more of an issue. Also, the Wakespeed manual has a warning about the minimum field being too high but the sparse Zeus manual doesn't mention it.

 

The workaround is to use something else for speed sensing; my old Isuzu has a Hall sensor on the camshaft which is designed for use with certain dash tachs. The Zeus isn't sensitive enough to pick it up, but I'm working on a bit of simple circuitry which should make it possible. It's also possible to mount a generic magnetic pickup near the crank pulley to get RPM data into the regulator.

 

The original Wakespeed WS500 is definitely more fiddly to set up than the Zeus, but the new Pro version with Bluetooth is much much easier now.

 

That really is pants considering my £8 reg chip manages that aspect seamlessly. If it starts to lose phase signal, it increases the field current a bit until it can see it again. In other words the minimum field current is dynamic. Not really that difficult I would have thought!

[Tiger 1057]

14 minutes ago, nicknorman said:

The low rpm issue was just about having a large alternator connected to a relatively short stroke modern engine - at low engine rpm the maximum available torque is quite low. This was not a problem introduced by an alternator controller, it was a feature of how Beta set up the pulley ratios, although made worse by Li batteries which can take the alternator's maximum current for long periods. But both the Zeus and the Wakespeed have a setting that causes the maximum field current to be reduced at low rpm to avoid the problem. I would have thought that a Gardner would not suffer from this problem so much, since it has a lot of torque at low rpm, and it was not about the absolute rpm anyway, it was about how much torque as a proportion of the maximum, is available near idle rpm.

 

That really is pants considering my £8 reg chip manages that aspect seamlessly. If it starts to lose phase signal, it increases the field current a bit until it can see it again. In other words the minimum field current is dynamic. Not really that difficult I would have thought!

Thanks very much for the explanation and information as it's very helpful.

1 hour ago, PeterF said:

As Cheesegas says, the Bluetooth version is easier. I have the older version,  but what has made a huge difference is the Android app for programming the WS500 makes it much easier. I have no idea if the app works on iPhone for the older USB version  but should be OK on Bluetooth, but would need checking. Prior to the app, Wakespeed programming was very clunky.

I have just had a look at my data through the Cerbo GX. I have no minimum field set and when the WS500 is producing no current with a field drive close to 0% the WS500 is still reliably reporting alternator (and engine) rpm from the domestic alternator close to that from the engine alternator. The field drive is only reported as whole numbers so 0% could be 0.4999%.

Thank you. Fortunately I moved to Android from Apple six months ago so that wouldn't be an issue thankfully 

[IanD]

20 hours ago, nicknorman said:

The low rpm issue was just about having a large alternator connected to a relatively short stroke modern engine - at low engine rpm the maximum available torque is quite low. This was not a problem introduced by an alternator controller, it was a feature of how Beta set up the pulley ratios, although made worse by Li batteries which can take the alternator's maximum current for long periods. But both the Zeus and the Wakespeed have a setting that causes the maximum field current to be reduced at low rpm to avoid the problem. I would have thought that a Gardner would not suffer from this problem so much, since it has a lot of torque at low rpm, and it was not about the absolute rpm anyway, it was about how much torque as a proportion of the maximum, is available near idle rpm.

Most diesels -- Gardners and Beta included -- have a similar shaped torque curve when scaled to maximum torque/power/rpm. Taking the Beta 43 as an example maximum torque at idle (900rpm) is just under 110nm (10kW output), similar to at maximum (2800rpm, 32kW) -- in between it peaks at just under 130nm at 1800rpm (25kW).

 

Assuming the engine power is the same and the alternator pulleys are chosen to keep the same alternator rpm, the load on the engine will be similar as a fraction of maximum power in both cases -- the fact that the Gardner may have twice the torque at half the rpm (same power) in all three cases (idle/max torque/max power) will make no difference, assuming the alternator crank pulley diameter is doubled compared to the Beta.

 

The key in both cases is to have the correct pulley ratio, and to pull back the field current at idle speeds -- partly to protect the alternator (they tend to fry if asked to put out a lot of current into LFP batteries for several hours at low speed, the cooling fan turns too slowly), but also in some cases the engine -- Beta have a big red notice in their manual (and engine bay?) saying something like "Do not charge for extended periods/heavy loads below 1200rpm". There's plenty of low-speed torque available in theory, but in reality using it may cause engine damage.

 

Edited Thursday at 14:33 by IanD

[Anonathy]

I use a MasterVolt Alpha Pro 3 on a 175 amp Beta/Iskra alternator to charge lithiums. It picks up the revs reliably and output can be set to 20% at low revs and built up as the revs increase. Takes some trial and error to fine tune to your engine but it's been reliable for me.

 

Unless the rest of your setup is MasterVolt then it won't communicate with it like the other options in this thread will with say Victron, but if you have a shunt reading the charge coming out what more do you really need to know in the moment? It does annoyingly needs a rather expensive USB adapter to set it up with and change settings.

 

I'm happy with it however. It works. I wouldn't discount it if you already have one in place. 

[blackrose]

3 hours ago, cheesegas said:

No reason for a slow revving Gardner to be of concern as long as you have the correct pulley drive ratio.

 

 

A neighbour of mine installed LiFePo4 batteries without any form of alternator protection and didn't have any problems. I don't know his set-up in detail but he told me it was a slow revving engine with a reasonably high-output alternator. Maybe that's how he's getting away with it?

[Tiger 1057]

15 hours ago, IanD said:

Most diesels -- Gardners and Beta included -- have a similar shaped torque curve scaled to maximum torque/power/rpm. Taking the Beta 43 as an example maximum torque at idle (900rpm) is just under 110nm (10kW output), similar to at maximum (2800rpm, 32kW) -- in between it peaks at just under 130nm at 1800rpm (25kW).

 

Assuming the engine power is the same and the alternator pulleys are chosen to keep the same alternator rpm, the load on the engine will be similar as a fraction of maximum power in both cases -- the fact that the Gardner may have twice the torque at half the rpm (same power) in all three cases (idle/max torque/max power) will make no difference, assuming the alternator crank pulley diameter is doubled compared to the Beta.

 

The key in both cases is to have the correct pulley ratio, and to pull back the field current at idle speeds -- partly to protect the alternator (they tend to fry if asked to put out a lot of current into LFP batteries for several hours at low speed, the cooling fan turns too slowly), but also in some cases the engine -- Beta have a big red notice in their manual (and engine bay?) saying something like "Do not charge for extended periods/heavy loads below 1200rpm". There's plenty of low-speed torque available in theory, but in reality using it may cause engine damage.

 

That's very informative. Thank you.

14 hours ago, blackrose said:

 

A neighbour of mine installed LiFePo4 batteries without any form of alternator protection and didn't have any problems. I don't know his set-up in detail but he told me it was a slow revving engine with a reasonably high-output alternator. Maybe that's how he's getting away with it?

He may be using a 'hybrid' system and possibly using a long wire system to control the alternator heating if necessary

15 hours ago, Anonathy said:

I use a MasterVolt Alpha Pro 3 on a 175 amp Beta/Iskra alternator to charge lithiums. It picks up the revs reliably and output can be set to 20% at low revs and built up as the revs increase. Takes some trial and error to fine tune to your engine but it's been reliable for me.

 

Unless the rest of your setup is MasterVolt then it won't communicate with it like the other options in this thread will with say Victron, but if you have a shunt reading the charge coming out what more do you really need to know in the moment? It does annoyingly needs a rather expensive USB adapter to set it up with and change settings.

 

I'm happy with it however. It works. I wouldn't discount it if you already have one in place. 

Thank you. My whole system is mastervolt including charger,, inverter and generator. I may well go back to roamer to discuss my Alpha Pro. I realise it's an ancient unit but it would be nice if I could safely use that rather than spend £900 on something that has all the bells and whistles but which I don't fully understand.

[cheesegas]

15 hours ago, blackrose said:

A neighbour of mine installed LiFePo4 batteries without any form of alternator protection and didn't have any problems. I don't know his set-up in detail but he told me it was a slow revving engine with a reasonably high-output alternator. Maybe that's how he's getting away with it?

If it's a slow revving engine with a pulley ratio setup spinning a high output alternator slowly, it probably isn't outputting anywhere near its maximum rated current so he can get away with it. If he were to spin the alternator faster to increase the output, he'd probably run into heating issues.

 

10 minutes ago, Tiger 1057 said:

Thank you. My whole system is mastervolt including charger,, inverter and generator. I may well go back to roamer to discuss my Alpha Pro.

If your whole system is Mastervolt, the easy choice is the Alpha Pro - way easier to integrate it into a Masterbus system.

[Tiger 1057]

2 minutes ago, cheesegas said:

If it's a slow revving engine with a pulley ratio setup spinning a high output alternator slowly, it probably isn't outputting anywhere near its maximum rated current so he can get away with it. If he were to spin the alternator faster to increase the output, he'd probably run into heating issues.

 

If your whole system is Mastervolt, the easy choice is the Alpha Pro - way easier to integrate it into a Masterbus system.

I totally agree with regards the Alpha Pro it was just that roamer haven't tested it. My understanding was that the alternator would be protected by the ATC wire shutting the alternator down if it was getting in difficulty. Unfortunately I'm fully aware of my limited knowledge and that saying about that being a dangerous thing.

This is the information that piqued my interest and led me to contact Roamer. I lifted the info from the FB 12 volt boating group.

A recent update for Roamer SMART5 batteries means we now support direct alternator charging (via a regulator) AND Hybrid installs on our drop in batteries.

Anyone who has looked into direct alternator charging will know that an unexpected BMS shutdown while charging can cause a voltage spike which has the potential to damage the alternator. Hybrid solves this by using a lead acid battery as a load dump that absorbs this spike - this solution is well documented on the group. If you’re using a regulator instead of hybrid however (eg Wakespeed WS500, Arco Zeus or Mastervolt AlphaPro), then up until now, you’ve been forced to buy very expensive batteries with NMEA2000 comms and an ATC signal.

A regulator requires at least 2 seconds advance warning of an impending BMS shutdown via CANbus/NMEA2000 or by using a keep alive (ATC) signal wire that cuts off before BMS shuts down. This tells the regulator to reduce field to 0% and back off the charging, thereby protecting the alternator. Previously, the only batteries with ATC and/or NMEA2000 BMS warnings were super premium options such as Victron, MG Energy and Mastervolt but we’ve now got this working with Roamer drop in SMART5 batteries.

The solution requires a Victron Cerbo GX and an ATC signal wire to the regulator. It works on both SMART4 and SMART5 batteries. We’ve been testing and refining this over the last 12 months using Arco Zeus regulators but it also works for Wakespeed WS500 or any other Victron integrated regulator. 

Roamer’s Dynamic Charge Control works by setting requested charge current to 0 and reduce the requested charge voltage BEFORE the BMS cuts off. We also use one of the Cerbo relays to provide an ATC signal that will trip if one cell is about to hit the high voltage limit. If it ever trips, this can be reset on the Cerbo screen.

We’ve also got a new temperature controlled charge protocol that reduces requested charge current according to temperature and battery capacity. It’s a myth that it suddenly becomes a problem at 0 degrees, the truth is that charge current should be scaled back as temps drop. We created this so that high power alternators can safely charge our batteries - the Arco 48V alternators can chuck out up to 9000W which is potentially dangerous at low temps, even with a large battery bank. It also works for all other charge methods however as long as they’re linked to a Victron Cerbo.

[Anonathy]

I think you may need to upgrade to the latest Alpha Pro (3) if you want to use temperature sensing for the alternator to reduce its output if it starts getting too hot. Even so it's still only about 1/3rd of the price of the other offerings and will integrate with the rest of your MasterVolt system.

[Tiger 1057]

42 minutes ago, Anonathy said:

I think you may need to upgrade to the latest Alpha Pro (3) if you want to use temperature sensing for the alternator to reduce its output if it starts getting too hot. Even so it's still only about 1/3rd of the price of the other offerings and will integrate with the rest of your MasterVolt system.

Thank you I will look into the 3. I’m grateful 

[Up-Side-Down]

On the face of it there are a couple of other (cheaper) routes to go down (B2B and a rather neat use of Victron Argofets devised by Kevin Mascall) but IanD has drawn your attention to why they are not sustainable and, therefore, that heat sensing is key.

[cheesegas]

1 minute ago, Up-Side-Down said:

On the face of it there are a couple of other (cheaper) routes to go down (B2B and a rather neat use of Victron Argofets devised by Kevin Mascall) but IanD has drawn your attention to why they are not sustainable and, therefore, that heat sensing is key.

RPM de-rating is also very useful on small engines with big alternators, and big vintage engines with big alternators with a high drive ratio. t's something which the B2B and Argofet thing doesn't address unless you get into the realms of having multiple B2Bs which are deactivated at low RPMs...

 

For example, on my 25hp Isuzu with a 90 amp alternator, if it's at idle RPMs in gear with the alternator running at full power, the engine runs much too slow and bounces around like a mad thing. With a de-rating curve programmed into the Zeus, it reduces the field at low RPMs and gradually increases it as RPMs increase. This is actually one feature of it which seems to work better than the Wakespeed's version.

[PeterF]

The WS500 derating with engine rpm works fine, my 175A Iskra alternator on the Beta43 produces 50A at tickover and increases linearly to 110A at 1200rpm 110A being the limit I have set to avoid it getting too hot. This is done via the pull back factor and idle rpm settings and they work perfectly. What is confusing is how it works because the manual is lacking in this area so people do not take the time to understand it as it needs a bit of thought and just use the "White space" set up which has discrete steps not a linear profile.

 

It may be necessary to send the ATC wire to the ignition wire on the Alpha Pro 3 to shut down charging as I do not believe it has a feature in wire like the Arco Zeus or Wakespeed WS500. I believe Ed Shires of Four Counties Marine preferred the Alpha Pro 3 over the WS500 when Wakespeed had the voltage / load control issues causing erratic engine rpm. But this is all solved now.

 

The other key thing with the Alpha Pro 3 is you will probably not be able to interface it with a Cerbo GX to get control of the charging voltage or current from the BMS. The Cerbo GX uses VE CAN (Victron Energy CAN), the Alpha Pro 3 will use MasterBus (or whatever it is called) and these do not speak with each other. Therefore you will loose out on what I think is a fundamental part of a well engineered system, the batteries control charging, the Alpha Pro 3 will be a standalone charger and you will only have ATC last ditch control.

 

Have you considered Mastervolt batteries if the rest of your system is Mastervolt the control hook up would be simpler.

[Tiger 1057]

Thank you. I hadn't looked at Mastervolt batteries as I thought they were expensive but as you mentioned them I had a quick look. OMG! They are eye watering expensive. You make some really interesting points so it looks like I'm going to re-evaluate my lithium upgrade.

[blackrose]

11 hours ago, Tiger 1057 said:

He may be using a 'hybrid' system and possibly using a long wire system to control the alternator heating if necessary

 

 

I'm not sure what part of "without any form of alternator protection" wasn't clear? But to reiterate, he's not using anything to protect his alternator.

[Tiger 1057]

11 hours ago, blackrose said:

 

I'm not sure what part of "without any form of alternator protection" wasn't clear? But to reiterate, he's not using anything to protect his alternator.

I hope it's not the case but that sounds like a recipe for disaster.

[cheesegas]

5 minutes ago, Tiger 1057 said:

I hope it's not the case but that sounds like a recipe for disaster.

You can just about get away with it if you have a large alternator that's spinning slowly as I mentioned. It'll be working well below its maximum rated output current and from what I've seen, it doesn't generate enough heat to cause an issue. This is what's likely to be the case with @blackrose's person - a vintage engine spinning slowly, a pulley drive ratio not spinning a large alternator very quickly.

 

However, holding the battery at 14.4v for long periods of time won't do it much good long term...

[Up-Side-Down]

It's also worth thinking ahead as to what strategy will likely not be passed by a BSS examination. The 'long wire' solution certainly won't!