Choosing LFP batteries for my conversion from AGM

[NoRain]

Can you click here. I cant even remember the items you need to enable but if you click the VRM you should be able to see the same screen that would be on the touch 50 or touch 70. To see the multi from the screen you show I believe you would need the Bluetooth dongle. But that hardly does anything.

Thx but that doesn’t help. The thing I think you’re referring to is Remote Console, and it opens up the Cerbo to your pad as if you were at the Touch70/50 screen. But the critical settings are not available there, as per my other post.

 

[Barking Sands]

Thx but that doesn’t help. The thing I think you’re referring to is Remote Console, and it opens up the Cerbo to your pad as if you were at the Touch70/50 screen. But the critical settings are not available there, as per my other post.

Right, but the Inverter is shown there. In addition, from that loacation, you can dowload the file from the inverter, modify it and reupload it back to the inverter remotely. Here is an AI overview.

Downloading and Uploading Multiplus Configuration via GX Device
You can download and upload configuration settings for your Victron Multiplus inverter/charger through a connected GX device (like a Cerbo GX) and the Victron VRM Portal.
1. Downloading the Configuration (.RVSC file):

• Ensure prerequisites are met:
  • Your GX device must be running Venus OS v2.17 or later.
  • Full access mode needs to be enabled in the GX device menu under Settings -> VRM Online Portal -> VRM Portal.
• Access the VRM Portal: Open a web browser and go to the VRM Portal website.
• Locate the Device List: Navigate to the Device List page on the VRM Portal.
• Initiate Remote VEConfigure: Scroll to the bottom and click the "Remote VEConfigure" button.
• Wait for the process: The system will read settings from each inverter/charger (approximately 85 seconds per unit, longer with Assistants), compile them into a file, and upload it to your computer.
• Download the .RVSC file: Save the downloaded .rvsc file to your computer's downloads folder. Do not open it in VEConfigure directly from the browser.

2. Modifying the Configuration (using VEConfigure):

• Open the .RVSC file in VEConfigure: Use the VEConfigure software (downloadable from the Victron Energy website if you don't have it) to open the downloaded .rvsc file.
• Make your desired changes: Modify the configuration settings within VEConfigure.
• Save the changes: Close VEConfigure and confirm that you want to save the changes. This will update the .rvsc file with your modifications. Important: Avoid saving the changes via the "File, Save As" menu as this creates a .vsc file, which cannot be uploaded using Remote VEConfigure.

3. Uploading the Modified Configuration (.RVSC file):

• Return to the VRM Portal and Remote VEConfigure: Go back to the Device List on the VRM Portal and click the "Remote VEConfigure" button again.
• Upload the file: Click the "Upload" button, select the modified .rvsc file, and confirm. The system will send the file to your Multiplus through the VRM.

Important Notes:

• Remote VEConfigure exclusively uses .RVSC files for uploads.
• Saving with "File, Save As" in VEConfigure creates a .vsc file which cannot be uploaded remotely.
• Updating inverter firmware resets settings to defaults, so downloading and saving your configuration is essential before performing updates.
• Some settings changes in VEConfigure, particularly Assistants configuration, may cause the Multiplus to temporarily switch off and on again.

 

[rslifkin]

Go to the device list page on the VRM site and you'll see the Remote VEConfigure button. The steps Barking Sands posted look correct to me. Basically it downloads a config file that you edit with VEConfigure. Then you upload the file back to VRM and the Cerbo pushes the config updates into the Multiplus.

 

[Barking Sands]

Go to the device list page on the VRM site and you'll see the Remote VEConfigure button. The steps Barking Sands posted look correct to me. Basically it downloads a config file that you edit with VEConfigure. Then you upload the file back to VRM and the Cerbo pushes the config updates into the Multiplus.

View attachment 165501

What device are you using for bilge alarm

 

[rslifkin]

What device are you using for bilge alarm

The second level bilge pump float switch in the engine room also serves as an alarm trigger. So the float is wired to power 3 things. The second level pump, and 2 relays. 1 relay has a 5 second time delay and activates the audible alarm. The second relay has no delay and is used to short 2 of the digital input contacts on the Cerbo. So when the float is lifted, the relay closes the contacts for digital input 1 on the Cerbo and the Cerbo is configured to interpret that as a high water alarm condition.

At some point when I figure out what I can fit in there, I need to add a second pump (and alarm) to the aft bilge, and I should probably also alarm the third level pump in the engine room bilge (which exists because I couldn't fit a big enough pump down low enough to be happy with just 2).

 

[Barking Sands]

The second level bilge pump float switch in the engine room also serves as an alarm trigger. So the float is wired to power 3 things. The second level pump, and 2 relays. 1 relay has a 5 second time delay and activates the audible alarm. The second relay has no delay and is used to short 2 of the digital input contacts on the Cerbo. So when the float is lifted, the relay closes the contacts for digital input 1 on the Cerbo and the Cerbo is configured to interpret that as a high water alarm condition.

At some point when I figure out what I can fit in there, I need to add a second pump (and alarm) to the aft bilge, and I should probably also alarm the third level pump in the engine room bilge (which exists because I couldn't fit a big enough pump down low enough to be happy with just 2).

Ah..very nice. Thanks

 

[NoRain]

K, thx guys. I do know about that; it does not work for me. However, your bringing it up caused me to want to refresh my memory as to why it doesn’t work, and in the process I may have made a discovery. And pretty sure it’s related to my configuration.

As you’ll see from the screenshot attached (and as mentioned previously) I’m running two inverters configured as a split-phase system. Even if I use the MKII wired configuration tool I can’t directly use VE.Configure etc etc….described in post #83. But that gave me a clue that lead me to my discovery. I’ll describe it here in case someone else finds themselves in similar situation.

When I download from there I do not get a .rvsc file. I get a .rvsm. This file will not open in VE.Configure. HOWEVER, it will open in VE.Bus System Configurator or VE.Bus Quick Configure (as per post #83). This is not well described anywhere, but….Victron

So I went ahead and downloaded the .rvsm file, then opened it with VE.Bus System Configurator. I chose the master device (L1) and clicked on Configure, and it opened VE.Configure, just as if I was hard connected through the MKII. I was able to see the settings, make a change, and save it back to the “remote” file (the .rvsm). At that point I’m pretty sure I could use the procedure from above to upload it to the MultiPluses and Bob’s your Uncle. I have not done so just yet due to an abundance of caution. I am going to run this whole scenario past the Victron group to see if my conclusions are valid before trying. I have been burned once, albeit it was a firmware update, where my entire system dropped. Particularly vexing because I required 120V to run my computer which was required to run the configuration software to re-configure the MultiPluses to allow them to boot in split-phase mode. I ended up running an extension cord out a portlight to another outlet on the dock to run the laptop. I got it going finally, but a few very tense moments because I was in quite uncharted territory. Hence my extreme caution now.

However, I’m pretty sure we’re on to something here. If so I’ll ask that they update the instructions for the use of Remote VE.Configure to cover the scenario where the user has a split-phase system, as I do. It’s more kludgy and cumbersome that I think it needs to be - I’d like to have those charger settings available directly through the Cerbo and VRM (like they were previously when the MultiPluses were connected via VE.Direct), but still better than having to connect the ‘puter to the system with a cable. And I’m also thinking maybe I can just build several configs - like one suited to cruising, one suited to winter season at the dock, etc - and then it seems it would be pretty straightforward and fast to upload the one I want.

Thx for the memory jolt!

 

[HeadedToTexas]

I wish I was working in the computery space you guys are in rather than the big cables, high currents, and skinned knuckles space I am in this weekend and for the coming weeks. I am much more comfortable there than here and I am concerned that I have bit off more than I can chew.

 

[HeadedToTexas]

Batteries are scheduled to arrive on Wednesday. I feel good about my math and the due diligence I did in selecting hardware. I feel good about building the rack to secure the batteries in the boat. I feel good about removing the heavy 8D AGMs from the lazarette. And I feel good about configuring the Xantrex to manage the charge profile for the new LFPs.

What I don’t feel good about is wrangling all the old cable out of the bilge and wrestling some of it back in for the new connections. Any words of wisdom?

 

[Diep]

You got this.

I haven't embarked on this project yet. (I've been following and I'll be doing it for next season) Some good advice I picked up somewhere is don't skimp on the tools. If you are making up new big cables get decent cutters and crimpers. Looking forward to hearing what other tips you get.

 

[Portage_Bay]

I'm not electrical wizard so I label everything. EVERYTHING. I make a one-line, a simple drawing of what goes to what. A full schematic. Then a graphic. Once they all agree then I stand a good chance of getting it right.

For the actual labor of pulling out old and new in it's whatever works. I've used pex to push through, then a string at one end, a shop vac at the other. Tie off the string, pull the pex now I've got a pull for the new. Maybe leave the pex in as "conduit".

I've used a 2 or 3 or 4 part block and tackle to pull out old that is well secured out of sight from when the boat was built.

Whatever works.

 

[Helmsman]

I used this for my N2K and electrical feeds for my electronics. Amazon.com

When pulling one cable pull parachute cord with it. That way you can pull the second one with it. Leave the last cord for future use. Take your time. When putting the connectors on the cable, use dielectric grease on the copper to reduce the risk of future moisture ingress.

 

[HeadedToTexas]

The good news on my "wrestling big cables" task ahead is that most of it, if not all of it, is removing cables. There are several that go from the main panel about 25 feet back to the lazarette. They are all bundled and zip tied and cutting all that off to let them slide feels like a no fun job, but it's got to be better than pulling new cable. The new runs are all short and readily accessible.

 

[Bob Cofer]

This is the crimper I use.

 

[HeadedToTexas]

I think my crimper is effective, albeit more manual.

My plan is to bring the negatives together before connecting to the main negative bus to allow a SmartShunt to track amps. And does this bank need fuses for each battery or does the entire bank need a fuse. Eco-Worthy limits the battery to 200 amps, but 3 batteries in parallel are still "limited" to 200 amps. Where should that fuse go?

 

[Bmarler]

Pretty sure you need to be within inches of the battery. I’d put the fuse before the switch, and if I remember right, within 7 inches of the positive post unless it’s sheathed. The battery post fuse are convenient, but I prefer remote. I sheath the wire so I have more room to play with to make it tidy.

 

[rslifkin]

Definitely fuses before switches coming from the batteries.

 

[Bmarler]

If the batteries were all cabled together at the positive posts, you could use only one fuse and switch as it acts like a single battery. You probably need a class t fuse for that though. Keeping them separately switched requires three fuses.

 

[HeadedToTexas]

So like this, yes? Is it worth a few hundred dollars to preserve the ability to shut off one battery at a time? If the fuse has to be within 7" of the battery, that makes it virtually impossible to combine the positives into a single fuse and switch, right?

 

[rslifkin]

I'd fuse each battery individually, but personally I probably wouldn't bother with individual switching.

 

[SteveK]

I'd fuse each battery individually, but personally I probably wouldn't bother with individual switching.

I agree in principle. The switch should handle the load of the batteries. But where do you stop when some batteries could potentially put out 2-3 times their rated amps. Looking forward to seeing the E13 revisions in July re the class T fuse. It was suggested a class T can only protect up to 400Ah of LFP as it only can protect up to 20K of surge. How does that apply to typical battery switches rated at 500A for instance.
In a perfect world one switch for maintenance is all that is needed and three separate ones in this case may not matter if there is a short.

 

[rslifkin]

I agree in principle. The switch should handle the load of the batteries. But where do you stop when some batteries could potentially put out 2-3 times their rated amps. Looking forward to seeing the E13 revisions in July re the class T fuse. It was suggested a class T can only protect up to 400Ah of LFP as it only can protect up to 20K of surge. How does that apply to typical battery switches rated at 500A for instance.
In a perfect world one switch for maintenance is all that is needed and three separate ones in this case may not matter if there is a short.

An additional fuse may be needed between the battery bus bar and the switch to protect both the switch and the cabling to it if the cumulative battery fuses are oversized to offer that protection.

 

[HeadedToTexas]

My thinking on individual switches (and fuses, though the 7" limitation is still confusing) is that it may be worth the cost of the components to preserve the opportunity to run this 3 parallel battery bank as either 280 Ah, 560 Ah, or 840 Ah in the event that one or more battery failed, needed replacement, or was otherwise unavailable for service.

 

[NoRain]

That’s a good idea, but you don’t need switches to do that. You can always just disconnect the cable from the battery….or pull the MRBF fuse if you decide to go that route. A switch would really only be called for if you were regularly removing one or more batteries from service, which I don’t think you are planning on. And the downside of the switch is two more connections per run, additional possible points-of-failure and if you are planning on removing a battery (or two) for any length of time you really should reprogram your chargers/shunt to reflect your new battery bank capacity.

 

[HeadedToTexas]

Hmmm, very true. I don’t plan on removing any batteries, but they will get turned off or disconnected once a year at haul out. I have been switch-focused because I want to be able to “turn the boat back on” now and then through the 6 month storage season to observe or charge batteries as needed. A switch seems so much more practical than loose and dangling cables, but perhaps I hadn’t thought that all the way through.

 

[NoRain]

Oh yes, you want one switch for sure. Just not three.

 

[HeadedToTexas]

So like this. I suppose there will also be a 4 post bus bar on the positive side to juggle that connection. And since there is one switch, I would prefer to have one fuse after the bus bar but before the switch, yes? That may be more than 7", but probably no by much.

 

[HeadedToTexas]

Bunding cables decreases their capacity because heat can not dissipate, so what incentive do manufacturers have to bundle cables in engine spaces like this? Is this carefully wrapped bundle of cables any neater than cables run like pipe fitters would run pipe; i.e. parallel along the wall? What a PITA.

 

[Delta Riverat]

You should have a house battery switch somewhere close to the helm. Mine is in the main panel to select house1, house2, both or neither (off)

I can't believe you have to go to the engine room to turn the batteries off.

 

[Helmsman]

So like this, yes? Is it worth a few hundred dollars to preserve the ability to shut off one battery at a time? If the fuse has to be within 7" of the battery, that makes it virtually impossible to combine the positives into a single fuse and switch, right?

View attachment 165588

The fuses are to protect the cables. Look up Blue Seas MRBF fuses. Use MRBF fuses on the three batteries at the positive terminals. Run cables for all three from there to a bus bar. From that bus bar connect a class T fuse, then cable, then switch, then to the positive bus bar that the panel and other components feed from. If your positive bus bar is large enough to handle the three battery feeds, the DC panel breaker, and the inverter, you can just put a class T fuse on the positive running to the inverter. Any other positive cables from that bus bar would need their own fuses to protect their feeds.