Does anybody have DAYGREEN DC2DC or step up/down Converter

[CaptainRivet]

Hi all,

Does anybody have DC2DC charger or converters (Step up/down) from daygreen www.daygreen.com and can tell their experience. Chinese company which only make these, nothing else and good webpage with local warehouses for quick shipping.
They look really good especially for marine as 100% watersealed and have a wide range to choose from. All are output current limited, so you can use them as battery charger, compared to eg Victron Orion Series (Not Orion TR/TR-smart DC2DC chargers) which state you can boost charge battery but fuse blows because they are not limited.

I am particularly interested in (but all reviews to any other model are welcomed)
DC2DC charger/Converter step up 12 to 28 or 29,4V optimum 30 or 40A output with remote (they call it ACC):
https://daygreen.com/products/12v-24...d-acid-charger

step down converter 24V to 13-13,8V in different amperage’s,
Especially this big one 120A:
https://daygreen.com/collections/24v...tage-regulator
A friend of mine using this to power the 12V 900W windlass on his boat with 24V LFP. Works well for almost a year now.

My Electrodacus BMS will switch the DC2DC charger/converter off via the remote if LFP battery is full means a cell reached what I programmed (3,60V at the moment). These will be also switched off by the battery monitor Victron BMV712 which monitor the lead starter battery already when starter is below 12,8V (or whatever I want) via the relay output, not draining the starter battery. So full DC2DC functionality. Switch on by ignition cable.
Means I actually don‘t need any additional functionality that Victrons Orion TR-smart has build in where you pay 280Euro for 24V/15A output, you actually get 12/13A when they run longer…
What especially obvious, the step down are much cheaper then step up but they all use the same circuit and parts, it’s just reversed. With daygreen prices are similar, with Victron and Mastervolt they differ factor 2-3…

[mcarthur]

I was looking at Daygreen's as well - so I'm keen to hear.

Mine would be 48-12 buck converters, big ones at 100a or so.
The 13.8v seem to be designed - in their words - for golf cart batteries rather than normal 12v. Hence I thought the 48-12 were more applicable than the 48-13.8 for running 12v appliances (MFD, VHF, etc.) off the 48v battery bank. But I'm happy to be explained the opposite if it's true...

[CaptainRivet]

Originally Posted by mcarthur

I was looking at Daygreen's as well - so I'm keen to hear.

Mine would be 48-12 buck converters, big ones at 100a or so.
The 13.8v seem to be designed - in their words - for golf cart batteries rather than normal 12v. Hence I thought the 48-12 were more applicable than the 48-13.8 for running 12v appliances (MFD, VHF, etc.) off the 48v battery bank. But I'm happy to be explained the opposite if it's true...

Very simple your 12V equipment is designed to be working in 10-15V Range. the more they get the better they work. 2nd you have voltage drop in your cables and in 12V not uncommon is 0,6-1V at the end and if your boat is older even more due to some corrosion at the connection (not much you need replacing but it’s there).
So if you convert from a 24V house to 13.8V and have 1V drop effectively 12.8 reaches your equipment. I would actually go even higher if adjustable, important is how many volt reaches your equipment not going over 14,5V. Especially Motors and pumps run and perform better and last longer the more they get so I have directly a Victron Orion TR 12/12 30A before fresh waterpump and fridge compressor and even bump it up from any voltage 9-18V (typically I have around 11,8 till 12,4V without) to stable 14,6V…they run like charm and actually need less amps due to less heat losses. For them less voltage means more amps=more heat in the coils of the motor or pump which kills the isolation lacquer over time=dead earlier.

[mcarthur]

Thank you CapnRivet.
I read that as the 48-13.8 is better (generally, and for our boat) than the 48-12 - correct?

While not helping your original question (though keeping it up the front page for the day ), for 48V the Calex 3000 is a bidirectional buck-boost 3000W converter. I wish they were more readily available, but the Daygreen is much cheaper (eek) and available (hmm).

[CaptainRivet]

Originally Posted by mcarthur

Thank you CapnRivet.
I read that as the 48-13.8 is better (generally, and for our boat) than the 48-12 - correct?

While not helping your original question (though keeping it up the front page for the day ), for 48V the Calex 3000 is a bidirectional buck-boost 3000W converter. I wish they were more readily available, but the Daygreen is much cheaper (eek) and available (hmm).

correct. Even better is an adjustable ouput.
This Orion Series is quite reasonably priced and has adjustable output.

https://www.amazon.com/-/de/dp/B01BF...72&sr=8-3&th=1
they also have 2 step down 24V->12V with 70A for 150 and adjustable output so I will go with them. the markup is quite small here to daygreen, Victron quality and 5 years warranty

[Miyalk]

Re-freshing an old thread, looking at the Daygreen 24v to 13.8V 200A, but its about $1000AUD whereas I can buy 3 of the Victron Orions in 70A and parallel them for under $600.

Will be using the step down converter to power all existing 12V house loads including anchor winch, so I feel like 200A is about where I need to be?

So Daygreen or Victron. (everything else I have is Victron.)

[CaptainRivet]

Originally Posted by Miyalk

Re-freshing an old thread, looking at the Daygreen 24v to 13.8V 200A, but its about $1000AUD whereas I can buy 3 of the Victron Orions in 70A and parallel them for under $600.

Will be using the step down converter to power all existing 12V house loads including anchor winch, so I feel like 200A is about where I need to be?

So Daygreen or Victron. (everything else I have is Victron.)

What anchor windlass do you have?
How much max current do you need when you exclude the windlass?

Instead the 200A version I recommend 2x100A one https://daygreen.com/en-en/collectio...=7132747268129.
They are just 150 AUD and you have redudancy.
But I would get a new 24V motor for your 12V windlass and job done. A new 24V motor is normally around 300 to 400Euro and if the old 12V motor has already some years of operation that's the way to go.
Most likely one 70A Victron will do it then.

My buddy also had 12V watermaker and one 12V power whinch plus 12V windlass was new (he bought the boat 10 month ago), that's why he went with the big step down converter that can power this all.

[Miyalk]

Thanks, need 125A max for the Lofrans winch, if every single thing was drawing current at the same time it would be less than 75A so 200A total would be fine.

The 2x100A is a good idea, Aus prices are in USD so its $460AUD roughly - less than 3 of the Victrons for sure. Just have to check the Greendays can be paralleled too.

Winch idea is a good one, would just have to check what price the winch motor would be in Aus.

[CaptainRivet]

Originally Posted by Miyalk

Thanks, need 125A max for the Lofrans winch, if every single thing was drawing current at the same time it would be less than 75A so 200A total would be fine.

The 2x100A is a good idea, Aus prices are in USD so its $460AUD roughly - less than 3 of the Victrons for sure. Just have to check the Greendays can be paralleled too.

Winch idea is a good one, would just have to check what price the winch motor would be in Aus.

So you have a 1000W Lofrans windlass...no it's not only 125A, that's normal operation. Image it's stuck under a rock or deep buried and you have to break it loose...you will see up to 280A for short periods, I have a 1000W too. Each of the converter should be able to manage that, tight but should work.

But i highly recommend get the 24V motor and you have piece of mind and one thing less that can break, it's 400Euro + taxes.
Ask for shipping rates from www.svb.de, I know they ship Aussi and NZ. If changing motor, change the oil in the windlass gears as well...they tell you it's lifelong but oil also ages and well then the life is shorter.
I always change all fluids if I buy anything with motors or gears, you never know how old it is, what quality was used and how it was used. Prevents damage and gear lasts longer, That 30$ for a bit oil is much cheaper then a new windlass or new gears.
Lifelong means max around 8 years...then even the best oil aged where its beyond its spec plus the containments in it.

[Miyalk]

Thanks again, its 1500W (125A), agree it can load up more than that, but the 150A breaker will trip pretty quickly in that case.

The 24v motor for the Tigre is going to be about $1000 landed in Aus, not sure I want to spend that much on going down that path!

Food for thought anyway!

[bhenry]

Try Jimmy Green marine. I just ordered a 24v tigres motor delivered to US west coast for $710.00.
Good folks to work with too!

[Miyalk]

Ok, my latest thought, why not just wire the anchor winch to the Stbd engine battery, (this engine has the larger 120A alternator) and run it off that? Then my house batteries will only need one small converter for all the other 12V load.

I already only use the winch when the engines are running as I presumed it was wired to an engine start battery!

[CaptainRivet]

Originally Posted by Miyalk

Ok, my latest thought, why not just wire the anchor winch to the Stbd engine battery, (this engine has the larger 120A alternator) and run it off that? Then my house batteries will only need one small converter for all the other 12V load.

I already only use the winch when the engines are running as I presumed it was wired to an engine start battery!

Yes you can do that and connect it to the starter battery. Assume that's lead, will work.
The converter solution for windlass kinda make sense for the small windlasses till max 1000W, a 1500W will surge into the 350-400A area easily and your windlass breaker has usually a time delay build in for that it's not tripping then but that surge is high enough to at least blow the fuses, most likley over time kill the 2x100 or 200A converter as thats the double what they are rated for, for sure when the anchor is stuck. That 150A breaker will trip at around 250A load....

Suggest you maybe look also on the long run when your leads are dead for eg 100AH LI-time trolling battery replacing the lead and use it to drive all 12V loads too. That Li-time BMS can do 500A and you can series connect them.

Means you have a 12V starter/house lithium and a 24V lithium house. So the only converter you need is one 24V to 12V and one 12 to 24V so you can transfer energy from one to the other. Wait for the release of Victron orion XS 25A 24 to 12 and 12 to 24V.
Actually the best case as your engine will stay 12V.