Can you use a victron DC solar controller as a DC to DC charger?

[outboard1196]

Backyard let me clarify, one 48V 100Ah battery has the same(and my terms ain't scientific lol) Amp hour Ah capacity as four 12 volt 100Ah batteries, plus WAY more energy capacity as i understand. I don't know the terms yet, but I did the research. I plan on 3 Epoch 48V @100Ah batteries for my 48V bank. I really should do a load calculation but it just doesn't seem important to my thinking at the moment. I will explain, it's not about my current(pun?) needs but about putting in a system to meet any future needs. My thought process is if I am having to spend thousands anyway why not do it with expansion in mind for a few hundred more? My current 12v Victron 3k inverter couldn't handle my needs for example if microwave and air fryer were on together. Yes we managed but why have to manage if we can set up system to handle most things being used in a more friendly day to day manner?

I'd recommend staying away from epoch.

 

[143107]

+1 for running two 3000/12 victrons. It will give you redundancy on the AC side. Set up for split phase you get 120/240. Single 12v house bank to manage. As stated before the capacity is the same. As long as the inverters can be mounted close to the batteries, the current isn't really an issue.
I think the biggest advantage being PV voltage requirement for charging. A single panel will produce enough vs requiring 2 in series. All boats have major shading problems, that benefit from multiple SCC and parallel panels.
Just curious, have you brought this up on cruising forums, anyone else do this with success? The 48v installs i've seen are because of electric propulsion. What is your plan for the windlass or electric winches?

Windlass isn't a big deal at all with engine running and alternator going. I am a sailor so not putting electric winches near my boat! Weekend warriors do that crap lol. Besides smart sailors get a electric drill and convert chuck to winch chuck . Definitely 100% going 48V, choice now is whether one 10k Quatro or 2 multi 2's 120v 5k's as suggested above. More and more thinking about 2 in parallel...it's just where the hell do i put them!!??? Hahahhahahahha

 

[143107]

I'd recommend staying away from epoch.

Please enlighten me before I drop thousands... I know the first generation we're problematic but I thought the second generation had it together?

 

[outboard1196]

Please enlighten me before I drop thousands... I know the first generation we're problematic but I thought the second generation had it together?

They haven't completely got it figured out, kind of long but lots of good info.

Thread 'Epoch 12V/460Ah IP67 after two months. Balancing: Oof!'

Nov 18, 2024

I've got one of these 12V/460Ah IP67 batteries from Epoch. Had it about two months or so. Here are my thoughts about these units...

TL;DR: I LIKE the battery. I don't LOVE it. It will work for my needs. But I have to put WAY too much time into getting it settled into the system and to stop throwing BMS alerts during normal charging. And there are a few too many things that I can't fix or even read myself (without the password to the app to change BMS settings).

1. BMS needs to be programmed differently.
1a. It shuts off the charging FETs at 14.0V if charge current is under 3-5A...

• Koyaanisqatsi
• Replies: 242
• Forum: General Battery Discussion

• 
• 

 

[143107]

They haven't completely got it figured out, kind of long but lots of good info.

Thread 'Epoch 12V/460Ah IP67 after two months. Balancing: Oof!'

Nov 18, 2024

I've got one of these 12V/460Ah IP67 batteries from Epoch. Had it about two months or so. Here are my thoughts about these units...

TL;DR: I LIKE the battery. I don't LOVE it. It will work for my needs. But I have to put WAY too much time into getting it settled into the system and to stop throwing BMS alerts during normal charging. And there are a few too many things that I can't fix or even read myself (without the password to the app to change BMS settings).

1. BMS needs to be programmed differently.
1a. It shuts off the charging FETs at 14.0V if charge current is under 3-5A...

• Koyaanisqatsi
• Replies: 242
• Forum: General Battery Discussion

• 
• 

Poor guy, that's a tough spot...but i am considering getting the marine battery, that has a different BMS and communication directly with victron system.

 

[outboard1196]

Poor guy, that's a tough spot...but i am considering getting the marine battery, that has a different BMS and communication directly with victron system.

I got the worst, bricked BMS. Hopefully it can be unbricked.

 

[yabert]

choice now is whether one 10k Quatro or 2 multi 2's 120v 5k's

10 kW in a ''small'' boat is nut
As I plan 3 kW in a 45' cat, please let me know what kind of load you are expecting to be short with 5kW continuous and 11 kW peak (let say 2 multi II 3kW at 12v).

 

[bluenomads]

Hey everyone, just strted educating myself on marine DC/AC systems. Life long professional sailor, but never bothered to learn about electricity.
I have read threads about similar topic but nothing really specific to my question. I have a 47ft sailing catamaran and plan to upgrade my DC voltage to 48V lithium from 12V lead. I have twin engines each with 80 amp alternators, and I plan to keep separate DC banks. 48 volt bank powering inverter charger, and all heavy power AC power appliances. With 12 volt bank powering my existing boat systems, all 12V DC. Pumps, autopilot etc. Anyway, one alternator with victron 12V DC to 12V DC charger charging 12V bank is simple. But using the other alternator to charge the 48 volt main house bank is proving difficult and costly. I found a promising 12V to 48V DC charger, but as it is no name equipment( Foval 12V to 48V 800W charger for LiFePO4) i am cautious about not cleaning power output before dumping into my planned 48V EPOCH batteries. And as I can't find a 48V to 48V DC converter, I was wondering if I could run this through a stand alone Victron 48 volt solar controller? What say you experts?
Also my grand plan, is four 400V Bifacial panels hung off back of boat to get energy from both sides, on bespoke aluminum framed solar stand. Two strings in series to their own individual solar controllers. Tied into a victron distributor and all the other victron smart bits. 10000w 48V Quattro, 240V, which i was hoping could provide 240 for heavy energy appliances on one leg and 120V on other leg for existing 120V? Is that doable?

We go between 12 and 48v on our catamaran.
All solar coming in is 48V (100/20's can do 48V) - 1.5kW now, plans for another 6kW or so. Multiplus II 5000/48 covers charging 48V from the grid.
The old 12v battery is used for big fast amps only - engine starting, windlass, crane and alternator sink.
Charging the 12v battery is either the alternator, or a 100/20 MPPT to keep topped up as it rarely goes down much.
Normal 12V for everything else doesn't come from the 12V battery - it is either as-needed from either 48-12 Orion's or (near future) a 3kW 48-12 Calex (which is bidirectional).
Emergency override to connect the 12V battery to the normal 12V circuit, but multiple Orions (catering for the amperage needed) means even if one or two blow I'll still have 48->12v on the circuit for VHF and lights and stuff.
Moving the house bank to 48V LiFEPO4 has saved about half the weight of batteries and 4-5 times the Wh. The 48V wiring is wonderfully easy compared to when larger 12V is needed (windlass is 1700W, crane 3000W, thrusters 2500W *each*)

 

[143107]

We go between 12 and 48v on our catamaran.
All solar coming in is 48V (100/20's can do 48V) - 1.5kW now, plans for another 6kW or so. Multiplus II 5000/48 covers charging 48V from the grid.
The old 12v battery is used for big fast amps only - engine starting, windlass, crane and alternator sink.
Charging the 12v battery is either the alternator, or a 100/20 MPPT to keep topped up as it rarely goes down much.
Normal 12V for everything else doesn't come from the 12V battery - it is either as-needed from either 48-12 Orion's or (near future) a 3kW 48-12 Calex (which is bidirectional).
Emergency override to connect the 12V battery to the normal 12V circuit, but multiple Orions (catering for the amperage needed) means even if one or two blow I'll still have 48->12v on the circuit for VHF and lights and stuff.
Moving the house bank to 48V LiFEPO4 has saved about half the weight of batteries and 4-5 times the Wh. The 48V wiring is wonderfully easy compared to when larger 12V is needed (windlass is 1700W, crane 3000W, thrusters 2500W *each*)

Breath of fresh air mate!! Thank you! Will probably reach out more if that's ok for advice as i go along. Very similar to my idea how you have your setup. I kinda chuckled when asked why I need so much power, and your going to 6KW +1.6KW...lol lol lol.
So as i have single lead for each engine, 1 alternator will be DC to DC converted from 12V to 48V for main bank chargingoff engine. Second alternator charging two new 300 amp hour lithiums via victron xs DC to DC charger. Already have the 2 100watt solar and smart victron controller working, so that will just stay as is connected to new 12v batteries. The planned 1.6 watt of bifocal panels will go through 2 smart victron 48v controllers to 48v bank. Going with 2 1600BTU 48V air-conditioning units for entire boat and getting rid of my 120v units.
What do you think of 3 100Ah 48V epochs for my main house bank?
This sounds fascinating, have zero clue about it "3kW 48-12 Calex (which is bidirectional)."
Trying to suss out whether it is a good idea to use victron 12V solar controller between my 48V bank and my 12V bank as a charging system if in desperate need to top up the 12v bank. Not sure if want to go DC to DC converters from 48V bank direct to 12v systems.

 

[yabert]

Will probably reach out more if that's ok for advice as i go along

Please stay public
Tips, advices and experiments are nice to learn. I plan 45' solar cat (11 kW of solar) with 48V battery and regular 12V stuff.
I didn't understand why do you like 48V system, but now, with 2 1600BTU 48V air-conditioning units + all others stuff, I understand your need for power.

I also used Victron 100/20 and they are awesome for the price. They will fit well with two 400W panels in series if VOC is low enough.
I used mine with two 500W panels and it work well, but VOC is low at 40V.

 

[shrspeedblade]

I'll be interested to follow your experiences, as I'm starting a sailboat conversion to 48v propulsion with a 12v house battery (Vatrer, already have it) and solar panels.