ACR or DC to DC charger?

[vechnyak]

I am going with DC to DC charger for my upcoming change. I have diode isolator with two AGM batteries now. one is for start and second one is for house. I am replacing house battery with a LiFePo4 and dc/dc charger is needed. If i was replacing with another AGM i would still add dc/dc charger because A) future upgrade to LifePo and because it will have much better charging management than what alternator has.

[Maine Sail]

Originally Posted by Cpt Mark

I too have the Sterling unit with 3 outputs. Each output can be programmed for the chemistry of the particular batteries and then there is one program that you can define any way you'd like.

Just to be clear, the Sterling charger cannot have each output independently programmed. Each output gets the same single charge profile you set it for.

This is why Sterling sells their Battery Chemistry Module

[Maine Sail]

Originally Posted by vechnyak

I am going with DC to DC charger for my upcoming change. I have diode isolator with two AGM batteries now. one is for start and second one is for house. I am replacing house battery with a LiFePo4 and dc/dc charger is needed. If i was replacing with another AGM i would still add dc/dc charger because A) future upgrade to LifePo and because it will have much better charging management than what alternator has.

Just be sure your alternator is considerably larger, in output rating, than the DC to DC chargers input rating, or you can burn out your alternator.

[er9]

Originally Posted by Maine Sail

er9,

I would urge you to read this article. It helps demystify the numerous myths (many of which have been brought up in this thread) surrounding ACR/VSR/Combiners and shows you how to do a correct installation for a cruising boat. Also remember that the ACR will work with any and all charging sources not just your alternator.

https://marinehowto.com/automatic-charging-relays/
.

thanks Maine Sail. read it quite some time ago but think i need to re-read it. also realizing that there are some gaps in my 12 volt battery knowledge i need to fill in.



and thanks i see you sent my charger this morning

[wingssail]

Originally Posted by smac999

You can not switch charging circuits like that.

When you turn the switch off when it’s sunny. All your lights / loads stay on directly fed from solar. That means You screwed something up.

If you want to keep the 1-2 switch and control manually. You still need to put all the chargers direct to battery. Pick one. If you want to charge both then stick it in all. To top them both up.

OK, smac999, I am not an electrical engineer, nor do I sell batteries, switches, ACR's, combiners, or perform boat electrical wiring for people.

So probably a lot of my thoughts are based in ignorance and have errors or problems.

But you are wrong in your assumptions about how my system works. (Yes, if you switch off the batteries you still allow power from solar, battery charger, wind or whatever sources you have. A well designed system allows for that.

Here is a diagram I made from the one mainsail published prepared by Compass Marine.

It is:

• Simpler, less components, can be easily operated by you, your wife, your crew anyone, without a diagram or a call to the expert. It is intuitive.
• It has fewer components, and is MUCH less costly
• It is TOTALLY monitorable. Everything that is happening is instantly observable at a glance, without fiddling with a complex monitoring device. Every time you walk by the nav station you see EVERYTHYING.
• It is infinitely controllable, meaning you can decide, in an instant what you want on or off, where you want power to come from and go to.
• No Black boxes which you have to trust because they do not tell you what they are doing.
• Safe, because you can shut things down instantly, as can you partner, crew member, anyone.
• Yes, this system puts some of the responsibility on the user. If you don't like that, go for black box automation

This is not the only way, or even the best way. but it is my way. I am not a follower, I do what makes sense to me. This is the system I have used for 34 years, it works perfectly and without problem.

[mitiempo]

Originally Posted by Q Xopa

Hmm a 'charger'? There are many different 'chargers'.

If you are referring to a AC Pro charge, agreed.

But for example a B2B Charger, nope, disagree. In fact that is the purpose of B2Bs to charge batts of different chemistries and even in some examples different Voltages.

I'm referring to just about any shore power charger as I believe a64 was.

[er9]

Originally Posted by wingssail

OK, smac999, I am not an electrical engineer, nor do I sell batteries, switches, ACR's, combiners, or perform boat electrical wiring for people.

So probably a lot of my thoughts are based in ignorance and have errors or problems.

But you are wrong in your assumptions about how my system works. (Yes, if you switch off the batteries you still allow power from solar, battery charger, wind or whatever sources you have. A well designed system allows for that.

Here is a diagram I made from the one mainsail published prepared by Compass Marine.

It is:

• Simpler, less components, can be easily operated by you, your wife, your crew anyone, without a diagram or a call to the expert. It is intuitive.
• It has fewer components, and is MUCH less costly
• It is TOTALLY monitorable. Everything that is happening is instantly observable at a glance, without fiddling with a complex monitoring device. Every time you walk by the nav station you see EVERYTHYING.
• It is infinitely controllable, meaning you can decide, in an instant what you want on or off, where you want power to come from and go to.
• No Black boxes which you have to trust because they do not tell you what they are doing.
• Safe, because you can shut things down instantly, as can you partner, crew member, anyone.
• Yes, this system puts some of the responsibility on the user. If you don't like that, go for black box automation

This is not the only way, or even the best way. but it is my way. I am not a follower, I do what makes sense to me. This is the system I have used for 34 years, it works perfectly and without problem.

thanks for posting the diagram. food for thought.



my mind wonders though...what scenarios/ events could cause that 300AMP fuse between the common post and the distribution panel to blow? if it did you would instantly loose power to anything connected downstream from the panel.



i guess that wouldnt be the end of the world because necessary items like VHF and bilges would bypass the distribution panel.


what is the likliehood of that 300 AMP fuse blowing? has it ever happened to you?

[Cpt Mark]

Originally Posted by mitiempo

Not according to Sterling. There is an optional Battery Chemistry Module that is designed for just that though.

https://cdn.shopify.com/s/files/1/06...22295855460459

The Promariner PronauticP is the same charger as the Sterling.

Whoops. My bad.

[wingssail]

Originally Posted by er9

thanks for posting the diagram. food for thought.

my mind wonders though...what scenarios/ events could cause that 300AMP fuse between the common post and the distribution panel to blow? if it did you would instantly loose power to anything connected downstream from the panel.

i guess that wouldnt be the end of the world because necessary items like VHF and bilges would bypass the distribution panel.

what is the likliehood of that 300 AMP fuse blowing? has it ever happened to you?

I am not sure if that fuse is correctly sized. However, if the positive bus inside the panel became shorted to any negative line, then plenty of current, dangerous current, would flow unimpeded. A fire would probably result if the fuse did not blow. Once that fuse blows you will have to find the problem before you restore power. The VHF and bilge pumps on my boat ARE on the DC distribution panel. There are NO wires directly to any power source, including the batteries, everything is switched, either by the battery switch or the individual sources such as solar and battery charger. So, if you blow that fuse, it is all dead. You gotta find the problem and fix it.

No I have never blown that fuse or any other fuse except one to the regulator, which is not shown. We have tripped circuit breakers, including cabin lights, and we have tripped the anchor windlass circuit breaker (not shown). Once I got my metal watch band across the terminals of a shunt and my watch band blew (which gave me a nice scar on my wrist) but since that was a 100 amp shunt, lots of current flowed without blowing the fuse. What was worse was that the band melted and it was still hot but I couldn't get it released. Never again.

[Maine Sail]

Originally Posted by er9

and thanks i see you sent my charger this morning

Most likely, I never know who's who when screen names are in play.. Thanks for the support!

[vechnyak]

Originally Posted by Maine Sail

Just be sure your alternator is considerably larger, in output rating, than the DC to DC chargers input rating, or you can burn out your alternator.

Thanks RC, Im going with Victron dc/dc 30amp and my alternator is 60amp. Hopefully thats enough...

[a64pilot]

It’s going to take a direct short to blow a 300 amp fuse on most any sailboat, that kind of current draw, unfused often quickly results in a fire. The fuse should never, ever blow.

The amount of amperage a largish house bank can provide is HUGE, really, really HUGE

[daydreamer]

We use a Balmar Digital Duo Charge, which is a dc-to-dc battery charger. I put it on in 2005 and it worked flawlessly and wonderfully for about 12 years. I see the replacement is now $215.

I find a B2B charger simplifies troubleshooting of the starting system, something I've had to do way too many times over the years.

We have AGM for both the single house bank and the single start bank on our catamaran.

[fritzdfk]

I am very happy with my Echocharge. The setup is very simple, troublefree and I don't think about it.

[jms28]

Originally Posted by Maine Sail

er9,

I would urge you to read this article. It helps demystify the numerous myths (many of which have been brought up in this thread) surrounding ACR/VSR/Combiners and shows you how to do a correct installation for a cruising boat. Also remember that the ACR will work with any and all charging sources not just your alternator.

https://marinehowto.com/automatic-charging-relays/

.

Reading this article with great interest and have a question on this particular statement: If ACR connects also when other sources like the shore line battery charger are working, isn't this de facto creating an override and making separate batt outputs for Starter and Service Bank obsolete? As in those separate outputs would normally manage the charging currents for both banks separately (depending on charge, batt type, etc.) but the ACR connects them anyway, potentially leading to the smaller Starter Bank being 'fried' while the Service Bank still needs charging? Or am I totally wrong here? Please educate me

Best,
Mike