ABYC and ISO Li reference diagram

[goboatingnow]

Here’s a diagram developed on the diysolarforum incorporating safety first principles but with manual overrides and protections. I modesty helped a few bits.

It’s sophisticated but extremely functional

Thanks to R Gleason for permission to share this

[rgleason]

There is a revision needed for the starter circuit 2/0 cable and 250a fuse, and perhaps a change to the dashed red emergency feed, along with some other explanatory notes.

[LeighC]

Can't see a manual switch (isolator) on the positive end of the LFP battery.
What if the N/O solenoid (relay) contacts weld closed or the control circuit doesn't switch off?

[rgleason]

Originally Posted by LeighC

Can't see a manual switch (isolator) on the positive end of the LFP battery.
What if the N/O solenoid (relay) contacts weld closed or the control circuit doesn't switch off?

The manual LFP "isolator switch" is incorporated in the 1-Off-2 switch, please review SK-2 (the second sheet). It is labeled "LFP Disconnect and SLA Emergency Feed" but thanks for bringing it up as others may miss that too.

What if the N/O solenoid (relay) contacts weld closed or the control circuit doesn't switch off?

Well, that's a thought we haven't considered. Its a heavy duty relay. I will have to think about this because it means we need another switch, and I wanted to keep this really simple.

If the relay welds shut or the BMS control circuit doesn't work, then the the fuse will likely blow.

[s/v Jedi]

I like it and think it’s about the same as the diagram I recently posted. I have to study the manual override a bit more…

Which BMS is this?

[rgleason]

Originally Posted by LeighC

Can't see a manual switch (isolator) on the positive end of the LFP battery.
What if the N/O solenoid (relay) contacts weld closed or the control circuit doesn't switch off?

@LeighC After further thought, what would you do if your On/Off switch contacts that is before the Relay Coils happen to weld closed? It is no different! You are "SOL" and when you smell plastic or sense heat you'd better hope that fuse blows fast, or manage to remove it before it blows!

This is where purchase and installation details are critical. Purchase reliable relays and mount them in well protected locations, well away from the cockpit and leaky lockers where corrosion can occur very fast.


@s/v Jedi Thanks. I didn't label the BMS, sorry. It is REC Active BMS. I will have a revised diagram shortly with more details on the DIYsolarforum.com thread Small Boat BMS/LFP with Backup under Marine, with wiring improvements, starter revision, etc. I would be interested if you see anything amiss or which can be improved.

[newhaul]

Originally Posted by rgleason

@LeighC After further thought, what would you do if your On/Off switch contacts that is before the Relay Coils happen to weld closed? It is no different! You are "SOL" and when you smell plastic or sense heat you'd better hope that fuse blows fast, or manage to remove it before it blows!

This is where purchase and installation details are critical. Purchase reliable relays and mount them in well protected locations, well away from the cockpit and leaky lockers where corrosion can occur very fast.


@s/v Jedi Thanks. I didn't label the BMS, sorry. It is REC Active BMS. I will have a revised diagram shortly with more details on the DIYsolarforum.com thread Small Boat BMS/LFP with Backup under Marine, with wiring improvements, starter revision, etc. I would be interested if you see anything amiss or which can be improved.

Would like to look at the revised diagrams posted in your solar group but have to be a member and I'm already part of to many discussions .

[s/v Jedi]

Some remarks:

- I don’t like the Orion wiring. Imo it should not be connected to a distribution breaker panel, but direct to batteries or busbars. Also, it requires fuses at each side, as close to the batteries/busbars as possible.
I know you try to keep it as small as possible, but why not fuseboxes like in my diagram? You can use them for bilge pumps, inverters etc. as well.

- I’m still looking at the manual override switch. Good use of available features but not convinced it’s the best setup yet. I need a little more time for this one.

- regulator: doesn’t the Wakespeed support a temperature sensor on the alternator? I would use an alternative if so. I know it’s nice to use a CANBus everywhere but it isn’t more reliable than a relay shutting it down.

[s/v Jedi]

On manual override: I think this model RBS (attached) is a better option. It replaces both components in your diagram. That leaves the dashed emergency power wire, which I would give a simple on/off manual battery switch (the small one) straight to the busbar.

The RBS will work just like the solenoid, i.e. normally disconnected. The manual override is built in and allows both forced ON and forced OFF, as well as release back to remote control.

I think it is simpler and I also think the RBS has a better track record than these solenoids, which aren’t bad either but have no manual override.

[goboatingnow]

Originally Posted by s/v Jedi

On manual override: I think this model RBS (attached) is a better option. It replaces both components in your diagram. That leaves the dashed emergency power wire, which I would give a simple on/off manual battery switch (the small one) straight to the busbar.



The RBS will work just like the solenoid, i.e. normally disconnected. The manual override is built in and allows both forced ON and forced OFF, as well as release back to remote control.



I think it is simpler and I also think the RBS has a better track record than these solenoids, which aren’t bad either but have no manual override.

The problem with the RBS is there’s electronics to spoof the operation of a normal contactor. That electronics can fail and leave the latching system unable to release the relay

The Other thing is the lunatic cost

The TE relay is available in versions upto 500A and is widely distributed by mouser and digikey and its also available on Ali for $50

It’s inherently failsafe and the nature of the coil is that the relay interlocking with the battery switch using the AFD terminals is easy to achieve.

A contractor relay has no electronics to fail and by simply applying or cutting coil Power you get an override feature. If a real physical override is needed a mechanical battery switch can be added to bypass the contractor relay terminals. The combined is still way way cheaper then the RBS relay

[s/v Jedi]

Originally Posted by goboatingnow

The problem with the RBS is there’s electronics to spoof the operation of a normal contactor. That electronics can fail and leave the latching system unable to release the relay

The Other thing is the lunatic cost

The TE relay is available in versions upto 500A and is widely distributed by mouser and digikey and its also available on Ali for $50

It’s inherently failsafe and the nature of the coil is that the relay interlocking with the battery switch using the AFD terminals is easy to achieve.

A contractor relay has no electronics to fail and by simply applying or cutting coil Power you get an override feature. If a real physical override is needed a mechanical battery switch can be added to bypass the contractor relay terminals. The combined is still way way cheaper then the RBS relay

Are you sure? When you turn the yellow knob, a powerful spring operates the solenoid just like any other solenoid. These use the same coil and spring and the same power to close the contacts; the difference is that they have a little catch/sear to hold it closed. This sear is held in place by the much lower, 13mA hold-power. When you take that power away, the sear releases and the big spring opens the contacts just like a regular solenoid.

Yes, price… but you don’t have to buy the manual switch and I have been able to find good deals on RBS switches (think $100)

Yes, electronics can fail and so can the coil in every solenoid, or the BMS. In this case, I have never heard of a failed RBS, while I have heard of many failed solenoids. Of course, there’s more of those.

[LeighC]

I like the N/O principle (Deadman) (GBN suggests) that needs power in the control circuit to keep the solenoid closed & must be repaired if not there, others may disagree & take the chance with high quality latching relays & high-quality design, wiring & components.
I suppose it's all about safe redundancies, any override switch must not be left in that position & problem fixed ASAP
Also, if using a large inverter (Multiplus e.g.) later, do REC recommend a precharge resistor to prevent large inrush currents (that charge the capacitors) from arcing the solenoid contacts?

[s/v Jedi]

A problem I see with the solenoid + manual switch is that users see the power consumption, or find out how hot the solenoid gets and use the manual switch instead, completely taking the BMS out. Probably not compliant either.

The Normally Open RBS with manual override seems like the sweet but costly compromise.

[rgleason]

Some responses (not necessarily answers)

Multiplus e.g.) later, do REC recommend a precharge resistor to prevent large inrush currents (that charge the capacitors) from arcing the solenoid contacts?

Yes, @svsagres (hrjohnson) has a similar setup in a small boat, with a multiplus. He developed much of the the approach for his installation. He uses a precharge as recommended by REC. He has a thread on DIYsolarforum.com too, Some pictures from my boat upgrade

s/v Jedi wrote:

- I don’t like the Orion wiring. Imo it should not be connected to a distribution breaker panel, but direct to batteries or busbars. Also, it requires fuses at each side, as close to the batteries/busbars as possible.

- I’m still looking at the manual override switch.. use RBS.

- regulator: doesn’t the Wakespeed support a temperature sensor on the alternator? I would use an alternative if so. I know it’s nice to use a CANBus everywhere but it isn’t more reliable than a relay shutting it down.

Orion wiring was originally on the Lynx bus. It has been moved to allow other equipment to fit on the Lynx and to have the DC Panel to provide on/off convenience, which is needed when the switch is on "SLA Emergency and LFP disconnect" (because it should be turned off). Also the Orion will be on infrequently due to the limited amount that the SLA will be down or depleted. If I move the Orion back, then something else has to be removed. Good point about fusing will fix that.

RBS switch. @svsagres is using the RBS. In my diysolarforum thread we had a long discussion about it, given the options, in the end I decided on a HD relay coil NO. I suppose your suggestion could be considered an option, but I like the single switch arrangement we have now have shown because there is no chance of getting something wrong. (I will continue to read about the RBS construction and reliability with interest.)

BTW we have fully accounted for the small power requirement and currently have 100w of solar which will be useful when on a mooring.

WS500 Regulator: Wakespeed supports temp sensor. Please review the diagram and look at sensors 10,11 & 12 from the WS500. Furthermore the Wakespeed WS500 is the only regulator that will integrate properly with REC Active BMS and Victron CerboGX that we know of.

[s/v Jedi]

Originally Posted by rgleason

Some responses (not necessarily answers)

Yes, @svsagres (hrjohnson) has a similar setup in a small boat, with a multiplus. He developed much of the the approach for his installation. He uses a precharge as recommended by REC. He has a thread on DIYsolarforum.com too, Some pictures from my boat upgrade

s/v Jedi wrote:
Orion wiring was originally on the Lynx bus. It has been moved to allow other equipment to fit on the Lynx and to have the DC Panel to provide on/off convenience, which is needed when the switch is on "SLA Emergency and LFP disconnect" (because it should be turned off). Also the Orion will be on infrequently due to the limited amount that the SLA will be down or depleted. If I move the Orion back, then something else has to be removed. Good point about fusing will fix that.

RBS switch. @svsagres is using the RBS. In my diysolarforum thread we had a long discussion about it, given the options, in the end I decided on a HD relay coil NO. I suppose your suggestion could be considered an option, but I like the single switch arrangement we have now have shown because there is no chance of getting something wrong. (I will continue to read about the RBS construction and reliability with interest.)

BTW we have fully accounted for the small power requirement and currently have 100w of solar which will be useful when on a mooring.

WS500 Regulator: Wakespeed supports temp sensor. Please review the diagram and look at sensors 10,11 & 12 from the WS500. Furthermore the Wakespeed WS500 is the only regulator that will integrate properly with REC Active BMS and Victron CerboGX that we know of.

The Orion on/off switch is on a small gauge terminal; you’re not supposed to disconnect the input for switching off. The on/off terminal supports a regular switch, relay contact, or a +12V on one of it’s pins (or DC negative, working from memory).

The Lynx bus is full? You don’t need to use a fuse position when you connect one of these to it: https://www.bluesea.com/products/502..._Bus_and_Cover

Yes it is nice to have just one switch. I have implemented a second busbar for the LA start battery/bank, then have feeds from both busbars to the distribution panel, where a selector could be used.
The problems I see with your choice is more high power cables with more connections (switch in parallel with solenoid), the solenoid power consumption and heat generation and the suspicion that users may use the manual switch instead to prevent the power consumption and hot solenoid.

I am not really familiar with the RECBMS, butI assume it will have a relay contact that can switch on high voltage warning? This is the only signal needed by a regulator as simple as a Balmar.