Another request to review LiFePO4 Schematic

[blinkerfluid]

I'm in the middle of re-doing all the DC electrical equipment (before the panel) on our new-to-us boat and I'm planning on converting over to Lithium. To ensure everything works together properly without too much fiddling, I'm planning on just using all Victron equipment.

I'm hoping I can get a few people (especially those with Victron knowledge) to review my plan and let me know if/where I've made mistakes. Also, if there are simpler or more cost effective ways of managing everything, I'd appreciate those comments too.

Color Key: Red = Positive DC, Black = Negative DC, Green = AC, Purple = Comm cables.

Let me know what you think! Thanks!

[AndrewA2]

Curious for feedback myself

[tkeithlu]

I have no Victron experience whatever (disclaimer).

Will the battery combiner allow you to charge the starter battery from the house bank, or alternatively, do you have a way to start the engine from the house bank? That's a "Plan B" issue for when you find you have a dead starter battery because of a failure in the alternator or voltage regulator.

I wasn't able to follow all the comm cables. My system has two volt meters on the main panel, one for AC and one for DC. Each has a rotary switch that allows me to check the voltage in each source: shore, genset, and inverter for AC, and house bank, engine starter, and genset starter for DC. Part of its utility is keeping track of the health of each, but it is also useful in checking "did I turn on the inverter," "is the genset putting out AC," and "is the engine alternator charging the house bank."

You've put a lot of thought into what appears to me an excellent system. Good luck with it.

[Steve_C]

My only observation is that you would appear to have the solar tied directly to the DC panel. You can disconnect the main battery bus from the system, but not disconnect the solar from the batteries without disconnecting the batteries from the DC panel? I would want a separate, controllable disconnect from the solar array to everything.

[blinkerfluid]

Thanks for the feedback!

To answer some questions; The Cyrix Li-ct can be wired so that when you push a button it will connect the house battery to the start battery for 30 seconds to allow starting of the engine. My panel still has volt meters wired into it that will still be functional, though I think I'll be able to get most of the info I need from the battery monitor; and if I really want to know what's going on in detail, I think most of the components will connect to my phone via bluetooth. Otherwise, I could add a Victron Color Control GX to the system, which would allow me to control and monitor pretty much everything.. but that's another $500+ part for an already expensive system. I should be able to add it later though if I ever decide I want it.

As far as disconnecting the solar from the batteries; I agree, that's something I missed earlier. The breakers at each panel would allow me to disconnect them manually if needed, but I think I'm going to add a Cyrix Li-Charge between the 100 amp breaker and the main positive bus. This will be controlled by the VE.Bus BMS so that once the batteries are full, the BMS will be able to shut off both the alternator and/or the solar as needed.

[CruiserAD]

Hi
I am doing exactly the same and I wonder why you choose the VE Bus instead of the BMS 12/200? My understanding is that this eliminates the need for the Cyrix and this BMS was designed for the new SMART batteries?
cheers Jan

[blinkerfluid]

I originally was going to use the BMS 12/200, but I think the main advantage to that BMS is that it has built-in alternator protection by limiting charge current. Since I'm using a Balmar regulator with an alternator temp sensor to control the output of the alternator, I didn't need the BMS to limit the charge current. Also, I think the max continuous discharge current is limited to 200 amps; while I doubt it happens often, the inverter I've chosen will draw more than 200 amps (we're going to have an electric galley).

[aybabtme]

Which Venus controller will you use? I see 3x MPPT but I'm not sure the CCGX has enough VE.Direct ports to accomodate that.

Looks pretty sweet to me, otherwise. I'm jealous of your LG panels, where did you get them and for how much, if I may ask?

[blinkerfluid]

I actually won't be using a venus controller.. I think on the lithium systems, the VE.Bus Bms handles everything and the majority of things connect directly to it. All the components I'm getting have built in bluetooth, so if I want to look at what something is doing, I can just use my phone. Since I'm not using a CCGX/etc, I can set up a network from the Multiplus and each component that isn't directly plugged into it or the BMS will communicate wirelessly, which includes the MPPTs. The MPPTs can also get the battery voltage directly from the batteries, which allows them to compensate for any voltage drop that may occur on long runs of wires.

I haven't actually ordered the panels yet, but I'll probably end up getting them from emarine since they're a forum supporter and are located here in FL where I am at the moment.

[aybabtme]

The advantage of using a Venus device is that you can enable DVCC, which will make your battery BMS tell all the charge sources how much amps they can push and at which voltage (similarly for the discharge current limits). I personally think that this feature (and other type of deep integration like this) is what makes Victron such a solid offering.

The CerboGX will have/has 3 VE.Direct connectors, so it would suit your needs. You're already paying a decent premium to get the Victron batteries, adding a Venus device in there would make sense. Although you can always add it later too...!