What VSR (Voltage Sensitive Relay) do I need to install on my yacht?

[coopec43]

Originally Posted by moseriw

I'm all for keeping the wiring simple and would have no problem using very heavy jumper leads to start the motor off the House Bank


The correct setting is some sort of emergency switch to connect the house bank to the starter bank.
Maybe a sound alarm is a good idea. I forgot to close the switch and my starter battery died. As a result the house bank was battered too. No damage but I think it was close to it.

I've been a bit Gung Ho (unthinkingly enthusiastic and eager) with my system and haven't fused everything. I was using my 240V wet/dry vacuum cleaner off the Inverter but didn't use the foam filter so water got into the motor and melted an earth wire to a battery. The starting bank batters are now 13.5V but the other one is only 10.8. I thought the 10.8V battery was kaput (broken) but now I read:

Can you mix different AGM batteries?
Batteries of the same chemistry and cell count can usually be run in parallel without a problem. The only big pain is they need to be brought to the same level of charge before you connect them together. And they should be separately fused.14 Mar 2021

Now I'm going to re-charge the flat battery back to 13.5V then connect them in series and hopefully everything will be OK (acceptable).

Only now am I putting fuses (and circuit breakers) in everywhere

[moseriw]

coopec43
What I learned is if you replace a battery that is exactly the same the old battery wil end your banks life very short. Expect one or two years so it seems to be better to replace all batteries of the bank at the same time.

[Adelie]

VSR??

[d design]

Originally Posted by coopec43

I think we are getting somewhere but my electrical system is 24V (not 12V)

They are 12 or 24.

[coopec43]

Originally Posted by Adelie

VSR??

What is that meant to mean?


Why don't you google it?

[Adelie]

Well there’s an industrial company in Nevada and a gaming company, which could be computer games or a gambling company.

Neither seem pertinent to a cruising forum.
Speaking of this is a discussion forum. People come here to ask questions or offer answers. Telling people asking questions to Google it seems out of place.

Or did you tell the OP to Google his question too?

[d design]

BEP, Trademark of Brunswick, sell a Product called a Voltage Sensitive Relay (Now called DVSR for Digital Voltage Sensitive Relay). The acronym for it is VSR.

[coopec43]

Originally Posted by Adelie

Well there’s an industrial company in Nevada and a gaming company, which could be computer games or a gambling company.

Neither seem pertinent to a cruising forum.
Speaking of this is a discussion forum. People come here to ask questions or offer answers. Telling people asking questions to Google it seems out of place.

Or did you tell the OP to Google his question too?

The thread title is:

"What VSR (Voltage Sensitive Relay) do I need to install on my yacht?"

(Have a look at my Comment #1)

(I don't know who abbreviated the title subsequently)

[PaulCrawhorn]

AKA "combiner" by the inventor Ann-Marie Foster of Yandina Ltd

the term "isolator" applies as well, but old-school those were diode-based suffered from excessive voltage drop.

Xantrex Echo Charge, Balmar Digital Duo, similar device, each unique properties, not generic.

"ACR" (Automatic Charging Relay) is a synonym also commonly used, see that canonical BSS unit I reco'd above

which BTW includes momentary override, no need to carry jumper cables if you don't want to.

That is when the 500A (conservative) rating comes in handy, especially for big diesels in the cold.

And as for price, the unit will outlast the boat you install it in...

Buy once cry once, but maybe that's just me.

[coopec43]

Originally Posted by PaulCrawhorn

AKA "combiner" by the inventor Ann-Marie Foster of Yandina Ltd

the term "isolator" applies as well, but old-school those were diode-based suffered from excessive voltage drop.

Xantrex Echo Charge, Balmar Digital Duo, similar device, each unique properties, not generic.

"ACR" (Automatic Charging Relay) is a synonym also commonly used, see that canonical BSS unit I reco'd above

which BTW includes momentary override, no need to carry jumper cables if you don't want to.

That is when the 500A (conservative) rating comes in handy, especially for big diesels in the cold.

And as for price, the unit will outlast the boat you install it in...

Buy once cry once, but maybe that's just me.

Thanks for that

I'm now looking at a B2B Charger. I've downloaded an article:


Dual Battery Systems — DC-DC charger vs VSR/Isolator

https://hooshmand.net/dc-dc-charger-vs-vsr-isolator/

I hope that will point me in the right direction.

[Adelie]

Originally Posted by coopec43

The thread title is:

"What VSR (Voltage Sensitive Relay) do I need to install on my yacht?"

(Have a look at my Comment #1)

(I don't know who abbreviated the title subsequently)

If you look under my avatar you can see my title which indicates that I am a moderator.

Among other things that gives me the power to edit thread titles.

If you look at the top of each post you can see the title of the thread when the post was made.

You will notice that post #22 explained what the acronym meant.

You will also notice that up to and including post #23 there was just the acronym in the title.

The portion of the title inside the parentheses (you know, the part explaining what the acronym meant) was put in the title by me.

I did this sometime in the hour after post #22 was made because I did it at work and I left work 1h6m after post #22 was made.

I don't know why your post 7hr after post #22 still had the old title. Possibly because your computer had an old token for the reply to this thread. Don't know, don't care, not important at this point.

I generally don't edit member's posting, but titles are one of the exceptions. I edit those for a number of reasons.
A. Fix spelling issues so the search function works better.
B. Fix spelling issues so that non-English speakers understand better what a thread is about without having to open it.
C. Fix cryptic titles with acronyms that are not widely known or used, because if I don't know it decent odds another person reading it won't either.

I have now discovered another reason to edit titles.
D. So that newbie members will not be driven away from the site by condescendingly being told to "Google it".

[Pete7]

Originally Posted by coopec43

Thanks for that

I'm now looking at a B2B Charger. I've downloaded an article:


Dual Battery Systems — DC-DC charger vs VSR/Isolator

https://hooshmand.net/dc-dc-charger-vs-vsr-isolator/

I hope that will point me in the right direction.

Having had a quick look at that article I suggest you bin it or delete it if you have downloaded it, because its nonsense, I quote:

Cars don't try to optimise to keep the cranking battery at 100%; you'll only get about 80% out of it. They simply don't need to, so why should they? A cranking battery will last longer if it's not fully charged,


I suggest you look at something from Sterling Power or Victron. At least shedloads of people have them and can advise if you have a query. Victron come with Bluetooth which is nice.

https://sterling-power.com/

The other option (and cheaper) is a VSR which we used for a decade without any problems, but ideally keep the battery chemistry similar, so either AGM or flooded lead acid.

Pete

[moseriw]

Yes, skip this 80% saying.. With a 75Ah Battery and an CCA of 900A one will crank up for 10 seconds 900/60/60x10 = 2,5 Ah! . Check your cars amperemeter. When you start up your car the alternator will work for max 10 Minutes and the battery is on 100%.

And then? How much current do you think your VSR will work on when the alternator stops charging? OK it is not so dramatic as alternators unsually keep up + 13V and this is enough for the VSR. On the other hand the Voltage differs always between 12,X and 14,4 V so the VSR is always switching on/off and the second battery is not actively charged by higher current as troug B2B Chargers which go up to say 30A actively pressing current into the battery.

[more]

i use VSR .when come on boat lifepo4 by solar is full i simply leave vsr in off position and go with engine.
if I am on boat and lifepo4 service battery is under 80% i start engine and switch ON VSR , after some time i look on the battery if show 90-100% i simply switch OFF VSR only for safety reason.
Victron VSR is better because
Cyrix-Li-ct
The functionality of the Cyrix-Li-ct is analogous to the Cyrix-ct.
The Cyrix-Li-ct will parallel connect a lead acid starter battery and a LiFePO4 battery:
- if the Charge Disconnect output of the VE.Bus BMS is high, and
- if it senses 13,4V (resp. 26,8V) or more on one of its power terminals.
The Cyrix will disengage immediately:
- when its control output becomes free floating, signalling cell over voltage or cell over temperature, and/or
- when battery voltage drops below 13,2V.
Start assist function: a short negative pulse will close the relay during 30 seconds (see figure on page 2).
A built-in transient voltage suppressor will limit the voltage spike that may occur when the Cyrix suddenly disengages due to
cell overvoltage or over temperature.
https://www.victronenergy.com/upload...n-120-A-EN.pdf

[PaulCrawhorn]

Current is never "pushed" into any load, including batteries charging.

The source only "offers", makes available up to X amps.

The load is in control of the current drawn.

A DCDC is required for LFP banks, because they try to pull an unhealthy high current

but a good alt VR that limits current can eliminate that need.

The other reason to go DCDC is to get a better charge profile than what the VR puts out, but that need is relative to the data sheet specs for the target battery.