Finalizing s/v Jedi DC diagram

[s/v Jedi]

Please comment on this schematic. I have found one item missing: there is an AC to 12V battery charger as well.

[BenBowSirocco]

I hope you take this as a compliment.. But I am going to copy the aesthetic of your diagram model.

Nicely done!

[tkeithlu]

As if you didn't know more about it than I do, Jedi.

I'll blow up your PDF and take a look. Might even show you mine.

[chowdan]

Not sure exactly what inverters you have, but my magnum says to have a service disconnect switch in the DC run to the batteries

[s/v Jedi]

Originally Posted by Pete7

Nick,

How are you going to take 12v from a 24v LFP battery?

Is there a risk in having a loop with the 4 DC > DC converters sending power around in a circle, that's almost perpetual motion

I don't know the answers, just pondering the questions.

Diagram nice and clear

Pete

The 24V LFB battery where I do this has a tap between cell 4 and 5. Using this will throw the balance of the pack off but some still do this for more than emergency use and Victron sells a balancer to fix that. I won’t have the balancer because I don’t intend to ever use it and if I need to, I have more to worry about

About the DC-DC converters: these are smart and only work when their source is charged like from solar panels or a spinning alternator. Also, they will have on/off switches on a control panel

[s/v Jedi]

Here is the updated diagram at full resolution.

[s/v Jedi]

Originally Posted by chowdan

Not sure exactly what inverters you have, but my magnum says to have a service disconnect switch in the DC run to the batteries

Thank you! I must admit that I don’t have that in the current setup and had to take the fuse out once so I will be adding these

[s/v Jedi]

Originally Posted by BenBowSirocco

I hope you take this as a compliment.. But I am going to copy the aesthetic of your diagram model.

Nicely done!

Go ahead I am using LucidChart for drawing which is an on-line app but works great. For anything more than the simplest diagram you have to pay but it’s worth it imo.

[s/v Jedi]

Originally Posted by tkeithlu

As if you didn't know more about it than I do, Jedi.

I'll blow up your PDF and take a look. Might even show you mine.

Great! The thing is that it’s easy to overlook things, like the service disconnect switches mentioned already. I expect more to show up and even then, while building this, I’ll find more

[Pete7]

Ok, see where you are coming from, but still not 100% convinced, but if your sure.

Now, you have a lot of 12v requirements, but from what I can see only the windlass needs 24v. Seems a shame to have a large 24v circuit only to have to then drop it down to 12 for the majority of services.

Would it be easier to have a 12v system with the exception of a small single 24v LFP battery and 12 >24v charger? this may depend on what kit you already have and are re-using.

Were are the battery BMS?

Again, don't know the answer, just curious.

Pete

[s/v Jedi]

Originally Posted by Pete7

Ok, see where you are coming from, but still not 100% convinced, but if your sure.

Now, you have a lot of 12v requirements, but from what I can see only the windlass needs 24v. Seems a shame to have a large 24v circuit only to have to then drop it down to 12 for the majority of services.

Would it be easier to have a 12v system with the exception of a small single 24v LFP battery and 12 >24v charger? this may depend on what kit you already have and are re-using.

Were are the battery BMS?

Again, don't know the answer, just curious.

Pete

Most of the DC system is connected to the distribution panel which is 12 and 24V but those circuits are not in the diagram. As much as possible will be converted to 24V. Many are already compatible with 24V like refrigeration, navigation lights etc.

The windlass is 12V now but will be converted immediately in order to eliminate a 12V battery in the forward section of the boat. A 24V motor for the windlass is readily available and cheaper than the other option.

The rest of the conversion will be done when items are replaced. We will always keep the 12V batteries in the engine room and the engine/genset starters and alternators at 12V. Most 24V boats have that and it solves the problems of alternator diodes blowing up when LFP BMS decides to disconnect.

The LFP is a 1P8S configuration of Winston 400Ah cells. I have my own BMS which will use the latching solenoid switches used in the diagram. I will need to do more develop work on the BMS code so will start with primarily monitoring the cells and setting alarms. I can manually balance as well, even with the bank in use.

[s/v Jedi]

Here is the diagram for the LFP setup. I am not sure yet if the second bank will be the same because I have an existing Lifeline bank for that now that will be okay for a couple more years.

[TheoWjr]

Looks very nice, actually lots similar to the setup I'm installing.

+1 on the switches for power going to the multipluses.
One other item I added is a pre-charge resister to the multiplus. Even when they are off there is a pretty good zap as the resisters charge when first connected. There are comments on the victron community pages about this. I just have a little box with a resister wired to a momentary switch to pre-charge, hold the button for a few seconds then no more pop when I throw the power switch.
Interesting idea on the emergency 12v take off, I may have to copy that.
Cheers,
ted

[guyrj33]

"The windlass is 12V now but will be converted immediately in order to eliminate a 12V battery in the forward section of the boat. A 24V motor for the windlass is readily available and cheaper than the other option."

Since they are DC motors, can you run the 12v motors on 24v without swapping them out?

[Stu Jackson]

Originally Posted by s/v Jedi

Go ahead I am using LucidChart for drawing which is an on-line app but works great. For anything more than the simplest diagram you have to pay but it’s worth it imo.

Interesting, and nice presentation. IIRC, Maine Sail recently commented that he's found this type of diagram, with the pictures of the devices, helps his customers.


Now, I gotta admit I'm an old school engineer [gee, finally first time I admitted that in public!!!] and I tend to prefer old time block diagrams with lettering inside the blocks describing the functions without pictures to be more understandable. Old fuddy duddy...



In thinking about it, I have realized, though, that the picture presentation is superior but wondered just what it was that I was having trouble with.


Thanks to you, Jedi, I finally figured it out:


When one takes up the space on the paper with the pretty pictures, what gets LOST is the LETTERING that describes what the picture represents. Unless one is familiar with the devices, unless you can actually READ what the device is, the diagram becomes difficult, if not impossible, to understand.


Thanks to your request, I did click on the thumbnail, even the hi res one, and even with using View Image and +, I simply can't read the SMALL PRINT!!!


So, in your updates, you might consider using LARGER fonts. The presentation, otherwise, is superb.



Thanks again for finally helping me to understand my personal predicament.