ABYC and ISO Li reference diagram

[goboatingnow]

Originally Posted by 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.

I actually have one of those TE relays the coil doesn’t even get warm because of the 130mA holding current.

Any latching relay solution is not fail safe.

Hence the TE represents an excellent feature set

Simple
Cost effective
Fail safe
Manual Override can be achieved by simple bypass of the switch completely ( that’s my own preferred perspective. ) that is what is a achieved in the circuit presented. Plus the added advantage of electrical interlocking to prevent inadvertent paralleling

[goboatingnow]

Originally Posted by s/v Jedi

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.

Again Nick it consume 130 mA that’s nothing it doesn’t even get warm.

So let’s drop the making up stuff. It’s a very good compromise unit. Cost effective practical and above all fail safe. ( the RBS unit is not fail safe as i understand as it specifically stated it powers up in the previous state.

The RECBMS , wakespeed and Cerbo GC now all effectively use Ve.CAN this is in essence non certified NMEA2000. It’s the closest we are coming to properly integrated multi source charging control.

Hence the enormous advantages of thd REC /WS combination including charge throttling , advanced alarms , centralised reporting , etc etc.

It’s very powerful and way so more then simple control wires ala balmer etc

The other option is it can all be centrally controlled strategies in the Cerbo using DVCC.

Not to mention all remotely monitorable via Victron VRM

sUre it’s a Pricey option but extremely flexible and capable

[rgleason]

Sorry, but I do not intend to use LFP, with the potential of a BMS shutdown turning the boat dark when shorthanded, without:

1. Putting all essential loads on a SLA battery OR
2. A very simple and foolproof way of switching to SLA Emergency feed to power the DC Panel and turn on nav lights and essential equipment while preventing paralleling of LFP and SLA and ensuring that LFP is disconnected.

I will look further into the way I've wired the Orion, perhaps a smaller breaker will toggle the on/off terminal. Thanks for the heads up.

I guess I don't understand your problem with the way I've wired it. It looks ok to me.

I wish someone would take apart an RBS to see how it works and is made, and posts photos and what is found somewhere, but it is a pretty expensive device to take apart. As I understand it latching relays can be problematical from a mechanical standpoint although @svsagres finds it to be reliable.

[newhaul]

Originally Posted by rgleason

Sorry, but I do not intend to use LFP, with the potential of a BMS shutdown turning the boat dark when shorthanded, without:

1. Putting all essential loads on a SLA battery OR
2. A very simple and foolproof way of switching to SLA Emergency feed to power the DC Panel and turn on nav lights and essential equipment while preventing paralleling of LFP and SLA and ensuring that LFP is disconnected.

I will look further into the way I've wired the Orion, perhaps a smaller breaker will toggle the on/off terminal. Thanks for the heads up.

I guess I don't understand your problem with the way I've wired it. It looks ok to me.

I wish someone would take apart an RBS to see how it works and is made, and posts photos and what is found somewhere, but it is a pretty expensive device to take apart. As I understand it latching relays can be problematical from a mechanical standpoint although @svsagres finds it to be reliable.

1 2 both switch does the job just fine .

[goboatingnow]

Originally Posted by newhaul

1 2 both switch does the job just fine .

Not so as it parallels LFP and SLA that’s not good at all

[goboatingnow]

Note I have an Orion it has no issue with having its inputs disconnected the remote input is intended for other applications

But it’s easy to interlock it so that it doesn’t become a perpetual motion machine !!! A spare set of contacts on the AFD relay would do the job

[goboatingnow]

In my opinion this “ reference diagram “ is a tremendous example of the current “ state of the art “ marine LFP. It’s safe , has good manual overrides and has the best integrated monitoring and charge control on the current market.

Sure you could skimp here and there but there’s no doubt Victron is way way out in front when it comes To system integration. Clearly third parties like REC and wakespeed who went to the bother of incorporating VE.CAN think so too

Personally I would use the Pi based Venus OS over the Cerbo as a lot of people have written extensions for that software as any perusal of GitHub will demonstrate , it’s probably the closest we have to an all boat integrated systems monitor and control. But Venus OS is complex and “ techy”

[newhaul]

Originally Posted by goboatingnow

Not so as it parallels LFP and SLA that’s not good at all

Explain the issue for a momentarily paralleled system don't you need to do that in the event of a dead start battery?
BTW the switch also goes the other way 1 off 2 try it sometime

[goboatingnow]

Originally Posted by newhaul

Explain the issue for a momentarily paralleled system don't you need to do that in the event of a dead start battery?

BTW the switch also goes the other way 1 off 2 try it sometime

The point here is to meet ISO and best practice to ensure differing chemistries can’t be paralleled.

Unless you configure your bms very differently you cant direct your LFP to start the engine. This is especially true of drop in lithium.

Hence the battery switch cant be symmetrical .

The easiest way around that is to carry a small Li jump start battery. Useful anyway

The reference diagram deals with a disconnected Li system. But it can’t deal with a dead SLA due to BMS limitations.

[newhaul]

Originally Posted by goboatingnow

The point here is to meet ISO and best practice to ensure differing chemistries can’t be paralleled.

Unless you configure your bms very differently you cant direct your LFP to start the engine. This is especially true of drop in lithium.

Hence the battery switch cant be symmetrical .

The easiest way around that is to carry a small Li jump start battery. Useful anyway

The reference diagram deals with a disconnected Li system. But it can’t deal with a dead SLA due to BMS limitations.

You do realise the EU is not the biggest part of the cruisers community nor this forum

Well mine can jump my engine just fine if my start fla is to low to crank the engine .

[newhaul]

Originally Posted by goboatingnow

Unless you configure your bms very differently you cant direct your LFP to start the engine. This is especially true of drop in lithium.

And there is a major issue with drop ins .

[goboatingnow]

Originally Posted by newhaul

You do realise the EU is not the biggest part of the cruisers community nor this forum

Has the biggest greatest sail boat producers on the planet , the greatest number of yachts , largest recreation industry.

It’s why METS ain’t in the US

It’s why EU produced boats are everywhere on the planet dwarfing everything else.

This is an Anglo sphere forum. That’s the bias.

I reckon a straw poll would result in 10:1 euro boats here.

Not go mention the ABYC and ISO specs are very similar anyway.

[goboatingnow]

Originally Posted by newhaul

You do realise the EU is not the biggest part of the cruisers community nor this forum

Well mine can jump my engine just fine if my start fla is to low to crank the engine .

li can easily crank batteries. It’s just BMS ones can’t.

[newhaul]

Originally Posted by goboatingnow

li can easily crank batteries. It’s just BMS ones can’t.

Mine does just fine and yes it has a bms that doesn't need to be bypassed to crank the engine. Sounds like the bms in your dropins is the weak link . My Daly is rated at 300 amp in and out .

[goboatingnow]

Originally Posted by newhaul

And there is a major issue with drop ins .

Yes one of the many

But there are easy alternatives to get around the inability of most BMS to handle cranking.

It’s also worth pointing out that many LFP s especially cheaper ones are 0.5C or 1C. Not suitable as engine start.