48V Lithium Electrical Upgrade

[dpmcgarry]

I've been a bit delayed in sharing some of the updates on my electrical upgrade project and in addition I have been lousy about taking pictures along the way. However I do recall some folks expressing some interest in this project since it is a little more unique / 'leading edge'.

Just to set the stage - I started with 1275Ah of house bank @ 12v. This was a somewhat screwy setup where 2 of the house batteries were in the Laz and the other 3 were under the floor in the forward cabin. The main / wing / genset are 12V. The bow / stern thrusters are 24V and each have a dedicated bank. I had a single Victron 12/3000 inverter that drove half of my AC panel.

I wanted to be able to run Aircon underway without running the gen, be able to run all AC stuff without having to run the genset, and be able to run minimal aircon in the staterooms overnight. I don't care if I have to run the genset twice a day but want to be able to just run it to charge the batteries. I plan on doing solar in the future.

The plan is to have 4 x Victron 24V 200Ah wired in 2S2P (two banks of 48V) -> so 400Ah @ 48V which is 19.2kWh. I can add another set of 2 batteries if I need it but wanted to see how this performed for the first season. Those will be connected to 2 X Victron Quattro 48/5000 inverter / chargers setup in split phase to deliver ~10kVA. There are 2 x Masterplus MacPlus 48-12 50A DC-DC chargers to cover the 12V loads on the boat. I am keeping the 3 batteries in the fore of the boat for now - mostly to catch the load from the windlass. I figure when those give up the ghost I can keep 1 lead acid up there and be fine. I am swapping the stock alternator on my engine (Cummins QSL9) with an American Power Systems 130A 48V alternator which should give me roughly ~7kw while underway. The primary input to the quattros will come from my AC selector switch at my main panel (I have both a fore and aft shore power setup). The second input to the quattros will come direct from my generator (12kW NL). At some point I'll add genset autostart.

Overall diagram attached.


Couple of pictures attached of the laz area where the house batteries were that I was going to remove. Also what was in there was a compressor / pump / electrical for a built-in freezer. That had a leak and pretty much "pooped" the bed so that is coming out too and getting swapped out for a SeaFrost Air or Water cooled compressor.

I made cardboard mockups of all the equipment to "dry fit" everything in the various spaces I needed to mount / install things. This proved to be a really good idea.

 

[dpmcgarry]

I'll break this up in a few posts....if nothing else to make it more suspenseful lol.

I fabricated a custom box for the batteries out of king starboard. I added lids so I can store stuff on top of the boxes when I'm all done since that area is pretty prime storage space.


One of the biggest bears in this project was that I needed to run additional AC cable for the second inverter / charger. I opted to be overly anal and ran 2 x 8/3 triplex. There were already 2 x 10/3 triplex present from the previous inverter / charger. 10/3 was sufficient per ABYC for 50A but for the output of the inverter I wanted to play it a little safe and drop it down a gauge. The run isn't especially long however it really was a royal pain in the rear. And boy does that cable get heavy after you are moving it around / rangling it a bunch.

I also likely didn't "need" to run triplex for each inverter. Split phase will share the same neutral and running a single ground for each of the inverters was likely ok....but I also wanted to not have to think too much if one inverter craps out and I need to run on a single inverter. In this setup each inverter can run independent or in split phase as a pair wiring-wise -> each inverters charging input will be 10/3 with proper neutral / ground and each output will be 8/3 with proper (independent) neutral and ground

 

[dpmcgarry]

All the gear came in and we (I have done a lot of the work here but have also enlisted help from Zimmerman Marine in Herrington Harbor who is great) got to work.

Getting the old AGM batteries out was actually not as bad as I thought (with two people and some clever use of lines to do lifting). However getting the inverters in and mounted was a bit challenging. It's hard to tell from the picture but that space is pretty tight and those suckers are heavy. It was a two person job in a one person space.

 

[dpmcgarry]

After that I got to wiring. 48V sure is nice for cabling gauge requirements. I picked up a quality crimper which really did a nice job. I also discovered that you can buy shrink tubing that you can use in a label maker which makes for nice wiring of all cable ends. The Victron Lynx units are really nice to be able to connect everything up cleanly. Pardon some of the photos as I was taking them upside down. You can see the Class T fuse block, the BMS, and the distributor. I still need to secure / cover up all the wiring but wanted to power everything up for a test run before I started doing that.

Right now everything is hooked up except for the AC connections to/from the inverters. I also still need to install the alternator / regulator, install some shunts, swap out a charger, and connect all of the VE.Direct stuff to some USB hubs. I already ran the USB homeruns from the engine room and fore area back to the pilothouse where the Cerbo and display are installed.

I'll try to grab some more pictures when I am back at the boat but it is getting close and at least during the initial powerup and programming of everything stuff was looking good.

 

[twistedtree]

Nicely done!. I love that Victron now has a power-in box that accepts class T fuses.

If you get an opportunity, I would love to know what the idle power draw is on the inverters? With the inverters on, but AC loads all disconnected (open the main AC breaker), put a clamp meter on the DC positive cable to each inverter and see what they are drawing. I ask because the 24V/8kVA and the 48V/8kVA inverters both draw double what the specs claim.

Keep an eye on the starboard since it doesn't support weight well in longer spans. Your bank of lynx devices will probably provide enough strength to that side panel, but over time the panel may sag. Same with the lids. They will probably sag in the middle over time. If you want to store heavier stuff on top of the battery box, you might be able to add a hardwood support or two to the under side.

 

[Iggy]

It looks great! Just wondering, why the shunts on the thrusters and starting batteries?

 

[dpmcgarry]

Thanks both. The nice thing is the BMS has a built in shunt so I can actually grab an accurate value for the inverters on without load. Will do that this week.

And yeah the one downside of the starboard is not supporting a bunch of weight as I noticed while I was sitting on the lid to do some wiring . Luckily I want to store stuff in there that takes up a fair amount of space but isn't necessarily heavy (various small parts, some tools, spare watermaker filters, etc.).

On the shunt question - I probably went overkill there but I'm basically using them for two purposes:
1. Volt meter on those battery banks
2. Measure the charging current actually going into the batteries

It turns out that the small shunts are really pretty cheap and they report data back to the Cerbo which is really "nice to have". Since I was already doing the USB runs for higher value shunts / to connect to the battery chargers I figured I might as well toss them on there and wire them up.

 

[wfleenor]

I have done similar, but didn't have the courage to do it myself. I have 6 24V batteries in a single 48V bank. I also have 2 inverter/chargers 48/5000 units. I have separated the 12V starter batteries, group 31 AGM from the LFP bank, but can revert to the AGMs through ACRs. I have 3 DC-DC converters 48V-12V to normally run the house. I have a separate 48V charger for the LFP bank and a 12V charger for the AGMs. The AGM also get charge from their respective engines - 2 power, 1 gen set. I also added 2500W of solar on the top of my pilot house. I did all of this last summer and have since left northern California and am in the Sea of Cortez. Not yet warm enough for AC, so I find I lose about 10-15% each day net. I run the gen set to make water run the dryer, or fill scuba tanks - all 240V requirements. It is all Victron products. W

orking pretty well so far. I run the gen set for around 4hours every 3-5 days - so far running the LFP bank betwee 30-95%.

 

[dpmcgarry]

Ah thanks for sharing those pictures! I most certainly want to get my wiring as clean as yours. Are your two inverters just operating "stacked" (since you mention you still need to run the genset for 240V)?

That's a lot of battery capacity! Besides the AirCon do you have other large loads you want to carry?

I'm curious what AirCon units you have / what you want to be able to run off your batteries.

How long have your 48-12V converters been in service? Ocean Planet Energy (who did my design) had some reports of the victron ones running into issues getting overloaded / burned out hence why I ended up going with the mastervolt ones...

 

[Iggy]

I like the pics! Having a 40' boat makes it hard to upgrade and install new tech. The room for it is very limited.

 

[twistedtree]

Thanks both. The nice thing is the BMS has a built in shunt so I can actually grab an accurate value for the inverters on without load. Will do that this week.

By all means give it a try, but the accuracy at such a low current may be questionable. Also measuring without the inverters powered (open your isolation switches) will give a baseline on the current reading.

 

[twistedtree]

At one point you talked about redundancy with the two inverters. You can get that, but it's not as simple as it might seem. I have the same issue with paralleled 8kVA 230V inverters. The issue is that once configured to operate in parallel or series, the inverters will ONLY operate in that configuration. If one fails, the other will not turn on. The work around is to go in with the config tool and reconfigure the survivor to operate as a stand alone. If you are familiar with the config tools and how to set up a Victron system, it all just an inconvenience. But if you are not familiar with how it all works, it could be a daunting, if not impossible task.

 

[wfleenor]

Ah thanks for sharing those pictures! I most certainly want to get my wiring as clean as yours. Are your two inverters just operating "stacked" (since you mention you still need to run the genset for 240V)?

That's a lot of battery capacity! Besides the AirCon do you have other large loads you want to carry?

I'm curious what AirCon units you have / what you want to be able to run off your batteries.

How long have your 48-12V converters been in service? Ocean Planet Energy (who did my design) had some reports of the victron ones running into issues getting overloaded / burned out hence why I ended up going with the mastervolt ones...

I am happy you had expert advice at Ocean Planet. I contacted them but now they don't do consulting without also installing. My expert did consult with a close friend e ahs at OP. For the near future (at my age that is all there is) I will only be in the SeC during the winter so I am not sure there is a great need for AC. I have 4 Velair units, installed in 2021. !6K units installed for each stateroom and the pilothouse, and a 21K for the saloon/galley. You might glimpse the pilothouse and saloon/galley units at either end of the batteries. I mostly run the inverters as stacked, but I can create single phase with them if needed. I simply schedule watermaking, cloths drying, and tank filling on the days I am going to run the gen set for battery charging. That lets me use more of the power the gen set can provide. I will agree that the 3 48-12V inverters are not ideal. I always have one of them very hot. There simply isn't a way right now to get them to share equally.

 

[dpmcgarry]

Ha - I just discovered that issue with 'redundancy' - I wanted to charge the bank with only one inverter connected to AC - no can do (without reprogramming). Oh well. Was able to get things hooked up to both AC lines and it worked great. Amazing how quickly you can dump electricity into these batteries.

 

[dpmcgarry]

I am happy you had expert advice at Ocean Planet. I contacted them but now they don't do consulting without also installing. My expert did consult with a close friend e ahs at OP. For the near future (at my age that is all there is) I will only be in the SeC during the winter so I am not sure there is a great need for AC. I have 4 Velair units, installed in 2021. !6K units installed for each stateroom and the pilothouse, and a 21K for the saloon/galley. You might glimpse the pilothouse and saloon/galley units at either end of the batteries. I mostly run the inverters as stacked, but I can create single phase with them if needed. I simply schedule watermaking, cloths drying, and tank filling on the days I am going to run the gen set for battery charging. That lets me use more of the power the gen set can provide. I will agree that the 3 48-12V inverters are not ideal. I always have one of them very hot. There simply isn't a way right now to get them to share equally.

Have you been satisfied with the efficiency / performance of the Velair units?

 

[wfleenor]

Have you been satisfied with the efficiency / performance of the Velair units?

My only issue is that they could certainly do better than their standard thermostats - rather clunky. Otherwie I have had no issues.

 

[heysteve]

Alas, I wish Victron had better cable management for the Cerbo GX. All those USB and misc. plug-in cables left to the user to figure out how to secure.

 

[Serene]

I am in the process of an electrical upgrade too and am interested in the Victron NG batteries and BMS. Looks like you are using NG gear?

Have installed 2 x 16k BTU A/C units, and a 12/3000 Quattro.

Next phase is replacing the BMV-501 with a smart shunt and Cerbo. Then adding 1kW Solar with MPPT.

Final stage will be replacing the 600Ah of 12V AGM house with 5 x 200Ah 12V Victron NG's (or 3 x 300Ah NG's) including the BMS NG. I know the BMS NG has a shunt included, so will move the smart shunt to the engine start batts, which will stay AGM. I can fit either 5 x 200Ah or 3 x 300Ah in the existing battery boxes. Thus the limitation.

I also have a 6kVA generator which I am happy to run a few hours per day, but hoping to get to a point where I can run the A/C unit that services the sleeping cabins off battery overnight in the middle of Queensland summer.

For insurance reasons I need to ensure my installation meets the AS/NZS3004.2 standard, thus the reason to go with the Victron NG batteries and BMS.

Any specific feedback on the NG gear?

 

[twistedtree]

Alas, I wish Victron had better cable management for the Cerbo GX. All those USB and misc. plug-in cables left to the user to figure out how to secure.

I agree. I think it's actually pretty difficult to do a neat and secure Victron install.

 

[Delta Riverat]

That is some real neat and pretty installation and wiring -

 

[Frosty]

I agree. I think it's actually pretty difficult to do a neat and secure Victron install.

You can say that again. Trying to keep it neat and tidy.... not for the faint of heart.

 

[Frosty]

By the way, a traveling couple (travel in a van) has some 3D printed covers. While they don't address the Cerbo "octopus," there are a couple for the Victron shunts and one for a common series 285 breaker. I have no association with them other than reading some of their articles over the years.

I have been considering the non-smart shunt enclosure (second image). Never liked how those fragile looking guts hang out, but don't have space for a big Blue Sea enclosure.

Store link:

Store | FarOutRide

Welcome to our store! Here are some FarOutRide goodies that we will personally package and ship from the van. Thanks for your support, you're awesome!

faroutride.com

 

[bglad]

Hi Don,

Big project and looking good! I assume the AC power source selector switch remains since the generator output is not shown and ties into the system. Is there a way to bypass the inverter system output to allow power directly from the dock or the generator in case the inverter system is not cooperating?

Also, the BMS is a single point that can fail and stops all your power. In my opinion having a back-up on hand and/or temporary work around would be a good idea. It is a nice feature about Victron batteries. If the other smart parts fail it is still a battery versus the types with built-in protection in sealed cases that are not.

 

[Frosty]

Also, the BMS is a single point that can fail and stops all your power. In my opinion having a back-up on hand and/or temporary work around would be a good idea. It is a nice feature about Victron batteries. If the other smart parts fail it is still a battery versus the types with built-in protection in sealed cases that are not.

I felt the same way and do carry a spare BMS aboard.

There is also a procedure shown on the last pages of the manual where (if need be) you can power-cycle the internal microcontroller of a battery. Of course if you have multiple batteries that's not going to be as big a thing (since it would only happen to one battery at a time).