Led drivers for 12v off grid system

Greetings!
I'm trying to get my head round the best way to power LEDs from a 12v off grid system. Forgive me if I'm not clear in what I want, this is because all of this stuff is fucking confusing when you're high as a kite all the time! But anyway, here's my situation: I've got a 525w solar panel setup with 400ah of batteries, I can expand this in the future once I've got things off the ground, but right now I just want to experiment and see what I can do in a 3ftsq space and pushing my power limits to the edge. I know how to grow weed well enough, check my diaries from years ago before I got busted and got more into "hands off" growing

I want to power 4x CXBs @ 50w each - from my 12v batteries. I have been wondering about using an inverter to run a meanwell HLG led driver, but the 15% efficiency loss of using an inverter combined with a further 5% loss of the driver got me thinking, there must be a way to convert 12v to 36v @ 1.4a so I can run my 4 LEDs at 200w with minimal efficiency loss. Anyone got any experience with running pure 12v off grid systems? I think that 200w might be a bit too much for my solar system as it is, but I will see how it goes, and maybe drop it down to 100w if it's sucking my batteries' balls dry!

I've run solar to power a lot of things in the past, but not a grow. I can tell you right now that 400ah of batteries and 525w of solar ain't gonna be optimal for 200w of lighting, even at 12/12 lighting schedule. I have a buddy running his 1kw grow with 4800ah and 3500w of solar, for reference. I don't know how much excess he's running, but when it comes to controlling flowering and vegetative cycles I would prefer to have more capacity. A cloudy day could throw your plants into flower far ahead of schedule. Then again, you could just grow autos.

By my calculations, 200w is gonna draw about 400ah over 24 hours, the panels will provide a chunk of that, if needs be I can drop it down to 100w and run each cob at 25w, or 2 at 50w if it's cloudy. Like I said, this can all be expanded, I'm just looking to set something up to play with at first. I will probably do an auto or two at first because I've got shit loads of freebies to use, and like you say, if the power goes tits up, it's not the end of the world.
My question at the moment is how to drive the LEDs, on ebay there is tons of 12v>36v constant current open pcb drivers that all claim 95% efficiency for peanuts, like £4. Are these actually worth using instead of an inverter and MW HLG drivers?

badgerbadger said:

By my calculations, 200w is gonna draw about 400ah over 24 hours, the panels will provide a chunk of that, if needs be I can drop it down to 100w and run each cob at 25w, or 2 at 50w if it's cloudy. Like I said, this can all be expanded, I'm just looking to set something up to play with at first. I will probably do an auto or two at first because I've got shit loads of freebies to use, and like you say, if the power goes tits up, it's not the end of the world.
My question at the moment is how to drive the LEDs, on ebay there is tons of 12v>36v constant current open pcb drivers that all claim 95% efficiency for peanuts, like £4. Are these actually worth using instead of an inverter and MW HLG drivers?

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No need to throw watts away with inversion, why convert from 12vdc to 100's of volts ac only to then convert back again? Wot you need is a 'Buck converter' tho i'm pretty sure the up shift type have a specific name (buck is high to low), these simple efficient circuits are cheap as chips too!

Boost converter is what I've been looking at, I've ordered one for £3, will see how it performs...

badgerbadger said:

Boost converter is what I've been looking at, I've ordered one for £3, will see how it performs...

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$3 one will be way too low wattage and will overheat most likely.

Doesn't meanwell make 12vdc drivers? I'll probably get back to this thread later for calculations but you're right, stay away from inverters and use a vdc driver instead.

LUXdrive A011-D-V-700 will drive one CXB-3590 at 25 watts. Sorry but this is best I've bing'd so far. http://www.luxdrive.com/content/FlexBlock_A011_V1.pdf https://www.superbrightleds.com/moreinfo/component-led-accessories/led-driver-flexblock-dc-buck-boost-constant-current/1058/2537/

200 Watts for 24 hours is 4800 Watts. A 400Ahr lead acid or gel battery is only good for 50% so that would give you 200Ahrs times 12Volts equals 2400 Watts and that is before conversion losses. Looks like you are going to need more batteries or cut down on hourly consumption. I don't know how much loss there is in converting from 12 Volts to 36 Volts. Long term if you are going to get more batteries think about a 48 Volt system which will require rewiring your panels and getting a new charge controller. You will save money on wiring because the higher voltage will need less Amps for the same Watts consumed.

freemanjack said:

$3 one will be way too low wattage and will overheat most likely.

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This is the thing I've ordered for a trial, if it runs hot I will stick a heatsink to it, it claims to be 96% efficient, but we'll see about that! http://www.ebay.co.uk/itm/191827311442.

As for my power needs, I'm definitely gonna need to beef up the system to run this, but I'll see how it copes with just one cob at a time..

Edit: I can adjust things to dramatically reduce my power consumption, ie. 3 cobs for 18hrs a day (150w÷12×18=225ah) almost half of my initial requirements.

badgerbadger said:

This is the thing I've ordered for a trial, if it runs hot I will stick a heatsink to it, it claims to be 96% efficient, but we'll see about that! http://www.ebay.co.uk/itm/191827311442.

As for my power needs, I'm definitely gonna need to beef up the system to run this, but I'll see how it copes with just one cob at a time..

Edit: I can adjust things to dramatically reduce my power consumption, ie. 3 cobs for 18hrs a day (150w÷12×18=225ah) almost half of my initial requirements.

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Well it claims to handle 250w, i'll be very interested to hear how it works, please keep us updated. Individual cheap boost converters on each cob would make multiple kilowatt rigs far more affordable as 12/24v dc transformers are ten a penny compared to anything 30v or above.

just a guess but i think you'd do better if you rewired your panels and battery bank and bought a new charge controller that was 48V. then you could run cobs directly off either 48V battery voltage or ~52V charging voltage from panels with no additional conversion (tho fuses would be wise with a massive DC supply like that)