Look forward to this buildout, especially the 48v system. I’m guessing the 12v 100a mppt is being used for charge/conversion of the 12v bank since 48v is still pretty niche (unfortunately). I think I remember reading about that off-piste use casein the Victron forums. Also looking forward to all the 48v ancillaries you’re able to find (fuses, breakers, connectors, etc), it seems like all the spec sheets I read say 9-32v.
Is testing the WS3000 on the cards as well with this system?
Also would love to hear about your battery selection process, and maybe a PSA about (not) building 4x12v series stacks from ‘drop in’ lithium batteries.
Hey Steve. Congrats on your new boat, she sounds amazing, especially I love the engine room! I love your 48V idea! I built 24V 800Ah battery a year ago for our sailboat and we love it! I used high quality Winston 700Ah cells, REC 16S BMS with CAN+Victron integration, Wakespeed WS500 with REC BMS via CAN integration. REC BMS is an excellent piece of kit and controls all our chargers(including solar) and inverters. The Winston cells are super generous on their capacity specs , and typically have 20% bigger capacity than they state, ie our 700Ah cells turned out to be 837Ah in my discharge tests. I highly recommend that you pick 16S configuration and not 16S2P config. I am sure this will be a super interesting project, if you need any info please let me know. Best regards, S
I was hoping you had splashed for an FPB!
I’m running 48V LiFEPO4, using an extra solar MPPT to charge the 12V Odyssey that runs the house / start (single 12v). Victron’s 48-12 is a bit limited but the MPPT is perfect.
Logic being parts commonality (same MPPT as solar), less rewiring / weight, and no BMS to trip out in event of catastophe. AGM is reliable for last resort.
You are correct about the MPPT - it will bridge the 48V bank to the 12V house “bank”. I’ve not found that many problems with fuses and such - there won’t need to be many since it’s just the inverter, alternators, and MPPT on that 48V bank.
Maybe. I’ve not been impressed with what I’m hearing so far around it, and I’ve had my own challenges with WS-500s where it seems like certain features are not fully baked. Relying on something like the WS-3000 to power all of my 12V side is a bit more than I’d like right now.
I looked at a lot of different choices out there, but none of them were really that baked. Combining 12 or 24 volt batteries to form 48 volts just didn’t seem like a good idea. I’m sure I will have something more to say about it in upcoming articles.
The evil empire in Get Smart (KAOS) is one way to look at it!
Alaska is definitely on the list!
Haha good one on the shoe phone.
ECPC has a very well reviewed set of cells by various folks on the 'net, and there are very few other 48V choices out there. 24 volt is great, but there are still limitations with the size of wiring and other bits that 48 volts gets passed.
I’m very familiar with the REC BMS as well as the WS500s. I’ve not built with Winston, but I have with others. This time around I will be using Victron’s Cerbo GX as a central controller along with a touch display, plus the ECPC batteries that are built with a lot of great components. Glad to hear about your setup - it might help if I end up going a different route!
Hah, I can’t afford an FPB!
That’s great to hear that you’re doing something similar to what I’m looking at. My design is almost finalized - I am likely going to use 2x 100 amp hour LiFePO4 batteries as my house 12v bank so that I have a constant voltage setup. I have become used to not having lights blink and having a more stable voltage overall the last 8 years or so with LiFePO4 boats.
What did you end up using for your 48V batteries? Any other challenges you found?
48V is a little difficult to get rated switches and fuses. Small blade fuses are a real hassle. The fail is not graceful.
I would keep the 48 scope limited
I stayed with AGM for the 12v as that way no possible chance of BMS disconnect for criticals. Only need a single battery.
I used same MPPT units for Solar and DCDC.
Winston is a little larger, but overperform and never ever fail.
Also avaialble in more sizes than most others.
48v alternator integration is a hassle.