How to deal with the alternator?!

[rgleason]

I think someone might be able to hack something which uses the Victron control wires to their batteries, but they would really need to study and know what they were doing and have a lfp bms/cell balancing system on the lfp that was compatible.

Doing this will probably void the warrantee on all victron equipment.

BTW, after more study, the wiring and controls for BMS 12/200 and Smart BMS CL 12/100 is very different. The Smart BMS CL 12/100 uses charge and discharge disconnect control wires.

Incidentally in Smart BMS CL 12/100 has a "Pre-Alarm Output for LED, Relay or Buzzer. This alarm might be used to disconnect the alternator external regulator field disconnect to protect the Alternator if it is directly connected to the LFP Batteries. These alarm wires are Normally free floating, and High (Vbat) in case of alarm, max. 1A(not short circuit proof).

I am not quite certain how this would work yet, because the wires go from low or 0v to battery voltage (1a max), so the relay would have to disconnect the field wire when the relay is activated, but what happens if this signal is intermittent? Would the relay ave to be latched relay? I don't think that will work.

[ronstory]

Originally Posted by rgleason

I think someone might be able to hack something which uses the Victron control wires to their batteries, but they would really need to study and know what they were doing and have a lfp bms/cell balancing system on the lfp that was compatible.

Doing this will probably void the warrantee on all victron equipment.

Rick--

The 3rd party REC-BMS has some limited ability to communicate between itself and Victron inverters, but it seems to limited to checking for discharge voltage only. See page 12.

http://www.rec-bms.com/datasheet/Use...MS_Victron.pdf

So it would not help with charge sources, but does give insight in the CAN commands Victron uses and expects.

That said, while I have a REC Active BMS and bought the Victron compatible version, but have not verified it's compatibility. I bought it for future proofing when I go blue on the next boat, whenever that is.

[rgleason]

Ron,

Thank you that's helpful. I do recall you advising something similar in another thread.
Rick

Originally Posted by ronstory

Rick--

The 3rd party REC-BMS has some limited ability to communicate between itself and Victron inverters, but it seems to limited to checking for discharge voltage only. See page 12.

http://www.rec-bms.com/datasheet/Use...MS_Victron.pdf

So it would not help with charge sources, but does give insight in the CAN commands Victron uses and expects.

That said, while I have a REC Active BMS and bought the Victron compatible version, but have not verified it's compatibility. I bought it for future proofing when I go blue on the next boat, whenever that is.

[Kerry1]

Originally Posted by s/v Jedi

Someone asked me how I deal with the alternator, so I’m posting about that here. The question concerns on damaging the alternator when a LiFe BMS disconnects from the positive busbar, sending a surge through the system which is likely to blow up the diodes in the alternator.

I already posted our diagram before but attach it here again because it shows what we’re talking about.

My solution is disappointingly simple: I avoid the problem by using AGM starter batteries and DC-DC converters. This means that the surge never happens. I have two Victron 12>24V converters which can take up to 60A alternator output and use that to charge the LiFe house bank.

If you have a 12V house bank you can do the same using 12>12V converter(s) which do the conversion of charge method.

The alternative is to stop the alternator before the disconnect happens. This means you need access to the field wire of the alternator and a BMS that can send a warning signal that you use to activate a relay which disconnects the field wire. Some battery switches can do the same thing. This method is similar to mine: you prevent the disconnect by stopping charging just before the event

Rather than start another thread, I am considering changing from LA to LiFePo4 batteries. I cooked the external regulator I have currently been using. On installing a Victron BMS 12/200 does that effectively replace the need for an external regulator? The original ext reg was a Next Step, which is out of production. My apologies for such ignorance with such a fundamental question. Be assured I'm just doing a cost exercise, the installation will likely be by professionals but just want to know what I'm in for. If I need the ext. Reg, plus the BMS 12/200 I will consider using the Zeus, but it's pricey. The reason for going to a Victron BMS 12/200 is that I have a Victron Solar controller regulating an 80Watt solar panel, and a Victron Multiplus 12/1600/70-16 inverter charger. It seems weird to me that a LiFePo battery monitoring system would still need an external, (or internal for that matter) regulator, because it would seem to me to be a similar job description to what the regulator does, just that the parameters are adjusted for the appropriate battery chemistry.

[s/v Jedi]

Originally Posted by Kerry1

Rather than start another thread, I am considering changing from LA to LiFePo4 batteries. I cooked the external regulator I have currently been using. On installing a Victron BMS 12/200 does that effectively replace the need for an external regulator? The original ext reg was a Next Step, which is out of production. My apologies for such ignorance with such a fundamental question. Be assured I'm just doing a cost exercise, the installation will likely be by professionals but just want to know what I'm in for. If I need the ext. Reg, plus the BMS 12/200 I will consider using the Zeus, but it's pricey. The reason for going to a Victron BMS 12/200 is that I have a Victron Solar controller regulating an 80Watt solar panel, and a Victron Multiplus 12/1600/70-16 inverter charger. It seems weird to me that a LiFePo battery monitoring system would still need an external, (or internal for that matter) regulator, because it would seem to me to be a similar job description to what the regulator does, just that the parameters are adjusted for the appropriate battery chemistry.

There are a lot of threads discussing this. You can probably find links at the bottom of this page, but to recap:

- for serious alternator charging (not just a bit during motoring in and out of the marina) you need to upgrade your alternator. I recommend a kit from Balmar suitable for your engine. This includes the alternator and an external regulator. You need to add the optional temperature sensor for mounting on the alternator so that the regulator can reduce the alternator output when it gets too hot. If you charge a start battery then you also need the temperature sensor for that battery, because it’s actual temperature requires changing the charge algorithm during charging.
A last item to keep an eye on is the belt. You need to limit alternator output to within what the belt supports. Because of that, I added a complete belt upgrade kit with new pulleys and a serpentine belt. Balmar offers kits that include everything you need.

- if you charge the start battery with the alternator then you want to add dc to dc charger(s) to take part of the alternator output and use that to charge the house bank. This replaces any ACR or isolator you currently have.

- if you charge the house battery with the alternator then the best solution is to keep the oem alternator to charge the start battery and add a Balmar kit as second alternator for the house battery.

Alternatively, you can use a single alternator setup as described above and charge the house battery with that, then use a small dc-dc charger to charge the start battery.

But now you get to the issue of damaging the alternator diodes and potentially other electrical appliances when the BMS of the battery decides to take it offline (called HVC, high voltage cut-off). This happens when one internal cell inside the battery reports a voltage that is too high, something the alternator or other charger cannot see. So you need to stop charging before that happens, which avoids the potential damage. There are two ways:

1. Some BMS’s have warning level outputs. You can use the HVC warning to drive a relay that shuts the regulator down.
2. Your BMS doesn’t have that capability. Now you can use your battery monitor, which must be a Victron Smart BMV (not the SmartShunt). The display unit of the BMV has a programmable relay with connectors in the back. After the monitor is confirmed to work correctly (default settings don’t work correctly) and shows an accurate SOC% (State Of Charge) of the battery, you can set the relay to trigger at 95% SOC and turn on again at 90% SOC, then use the relay contacts to shut down the regulator at 95% and turn it on again at 90%. This means you can’t charge the last 5% with the alternator but that’s okay.

There are more options but I am against them. Don’t let a BMS control anything more than the battery it is for. Using a warning output like I describe above is the furthest I recommend to go with integration. The method with the battery monitor is superior in that you can use whatever batteries you like, for example the affordable LiTime batteries even with non-Smart BMS (I am in year 3 of testing them and they simply work as claimed).

I reject all other options because in my opinion they are inferior and/or not worth the effort. Trying to keep things simple and universal have proven to be superior in the long run as well as most cost effective.

[rslifkin]

Depending on the amount of power you're dealing with there's also the option to feed directly to the start batteries and use DC-DC to charge the house. Especially as bigger DC-DC chargers have become available. That takes care of the alternator protection issue, but it's impractical if you'd need to parallel more than 2, maybe 3 chargers.

On any engine that needs power to run I tend to lean towards this option or 2 separate alternators and there are less failure modes that will prevent the start battery from being charged (to avoid the engine electronics drawing it down).

[Dan Kimblad]

I just love my concept. This morning I let her down to the sea and I rev up the enginge to 2300 rpm
I should discharge the LFP little bit more before but I am satisfied with 276Amp
Only one alternator is enough

[hjohnson]

Originally Posted by Kerry1

Rather than start another thread, I am considering changing from LA to LiFePo4 batteries. I cooked the external regulator I have currently been using. On installing a Victron BMS 12/200 does that effectively replace the need for an external regulator? The original ext reg was a Next Step, which is out of production. My apologies for such ignorance with such a fundamental question. Be assured I'm just doing a cost exercise, the installation will likely be by professionals but just want to know what I'm in for. If I need the ext. Reg, plus the BMS 12/200 I will consider using the Zeus, but it's pricey. The reason for going to a Victron BMS 12/200 is that I have a Victron Solar controller regulating an 80Watt solar panel, and a Victron Multiplus 12/1600/70-16 inverter charger. It seems weird to me that a LiFePo battery monitoring system would still need an external, (or internal for that matter) regulator, because it would seem to me to be a similar job description to what the regulator does, just that the parameters are adjusted for the appropriate battery chemistry.

I'll provide the contrasting view to Jedi here. If you can build a system where the BMS manages everything, it's a great way to go. The BMS knows best what voltages/currents it wants, and if it can inform the rest of your charging sources on that, then you wind up with a beautifully integrated system that requires zero muss or fuss to keep working.

We're into the third year on our system, with a REC ABMS on a 460AHr DIY battery, a Wakespeed WS500 managing our alternator, and a Cerbo GX manging our MPPTs and Inverter/Charger. It's been absolutely trouble free, and the best part is that I can monitor it from anywhere on earth.

It's also radically less complex, as the only wires other than power running around is a CANbus cable (between the BMS, Wakespeed, and Cerbo) which is basically no different than an Ethernet cable, the VE.Bus ethernet cable between the Cerbo and Inverter/Charger, and the VE.Direct cables between the Cerbo and the MPPTs.

Unlike the contact closure cables that Jedi advocates, I can actually read the status of all the charging sources, see if they're throwing alarms. I know the temperatures of the equipment, how much current each device is producing, and whether they're showing any faults or alarms. All I have to do to diagnose the thing is to log from either my phone or my laptop, and again I can do that from anywhere there is an internet connection. Having that data on your devices is immensely useful, and something that you don't get with just on/off wire signals.

I can also do helpful things like limit my system voltage while the boat is in "storage mode." so right now, for example, I have my bus voltage lowered to 13.3V so that the battery is sitting at around 60% SoC. That's where it sits when it's just chilling in the marina. The day before I plan on heading out on anything other than a day sail, I'll log in remotely and remove the limit, letting it go back up to 100% SoC. Because of the system, I can also do things like remotely manage my hot water tank, so again the day before I'll turn the hot water tank on so that it's nice and hot before we leave.

If you're not going to go whole hog into a fully integrated system, though, the other option is to look at the new Orion XC DC to DC charger from Victron. It's 50A, but more importantly it's controllable under DVCC, which means that it will act as an integrated part of the system as a power source into your house battery.

TL;DR: Integration is a beautiful thing.

[s/v Jedi]

Yes, integration is a beautiful thing but only as long as a dealer distributor with spare parts is at hand.

I don’t see that future for blue water cruisers and prefer a system where I can put in any battery that is available on the market. Any alternator regulator that is programmable (most don’t have CANbus) etc.

I am not against integration of the management interface and do recommend a Victron Cerbo, collecting all data, reporting via the Internet when that’s available etc. The thing is that everything keeps working when it fails and one can still install an incompatible charger and will be just fine.

Also, a charger that is not controlled by the BMS (it’s not a CMS but a BMS so manage the Battery, not the Charger) isn’t stupid per se. Many are programmable and can charge the house battery perfectly. Once programmed, they know exactly which voltage and amperage to charge the battery with.

Edit: forgot one important aspect: if there is any bug in the software or any incompatibility between manufacturers then the integrated system can become completely bricked and the boat without power. We recently saw such an event, I don’t remember if it was here or on the Facebook Victron group. It required a Victron tech and ordering new parts to get right.

[Fuss]

yep, integration is nice but simplicity is best … otherwise there is no time to monitor the wind, it’s replaced with monitoring the electrics.
ps… the sterling system can be a 1 time protect… and then it’s damaged but you do not know… think about that.

[Fuss]

Originally Posted by Pitchondesign

The ultra capacitor eliminates the need for the dc-dc charger. Other than that, no advantage. I was thinking in terms of a 12v lithium only system, where start and house banks are lithium. In such a system a small ultra cap battery would provide better protection than a zap stop diode or the Sterling system, both of which can be blown without any indication.

that’s right they can be blown with no indication so don’t use these 1 time solutions

[Fuss]

Originally Posted by s/v Jedi

For what reason? I think capacitors only make sense when you want a -lot- of current for a very short time, like the bass power amplifier in car audio, but for 12V service on a boat, coupled to an engine mounted alternator, a starting service battery makes more sense imho. AGM is pretty happy at a high SOC so seems a better fit than a capacitor.

not really, a ultra capacitor makes more sense than agm… so why
because you can have the lithium as part of your house bank… a big plus point as there is no agm hanging around just starting the engine… i used to have this and was a big proponent of the starter only having one job.
its not only part of the house bank but can start your engine if needed.
the ultra capacitor is the main engine starter it’s small and light.
you only have one type of cell onboard providing the ultimate in redundancy .

[Fuss]

having only one type of lithium cell in multiple battery configuration plus a small ultra cap starter makes the most redundancy sense for long distance cruising sail boats at the moment.
i ran without the ultra cap for 1 year and my eve cells had no problem starting my engine.

[Fuss]

in my opinion you go with all lifepo4 or all lto, the days of mixing types is over.
but why would you go all lto… bigger and heavier….unless you got them cheap!
take your choice and have redundancy
do not design anything that blows your alternator when a bms disconnects… bms disconnects are for completely unexpected events and systems should be designed around this.

[s/v Jedi]

Originally Posted by Fuss

not really, a ultra capacitor makes more sense than agm… so why
because you can have the lithium as part of your house bank… a big plus point as there is no agm hanging around just starting the engine… i used to have this and was a big proponent of the starter only having one job.
its not only part of the house bank but can start your engine if needed.
the ultra capacitor is the main engine starter it’s small and light.
you only have one type of cell onboard providing the ultimate in redundancy .

The capacitor will not start the engine. The ones that do are actually LTO cells.