Larger LED driver


G’day, I bought a 300w LED from Ebay auction, anyway i opened it up and it has 2, 45w drivers! So my question is if the LED’s are 3w (100 LED’s) can i swap the drivers for 150w ones?

Cheers, Brendan.


Two answers to that question.



If you use them, they may work for a while and then quit completely.

No, they’ll cause your lights to burn out faster or they won’t work at all.

Wattage isn’t the only issue here. It just is part of the formula. Voltage plays a big part as well. Ohms law is where I’m coming from.

Each LED requires voltage, power, and current and it provides resistance.

If the actual rating of the LED is 12 volts, and you have 45 watts, then the other two readings will be approximately 3.75 amps and 3.2 ohms. If you change the power (watts) to 150, the readings change to 12.5 and 0.96. If your LED’s are rated at higher than .96 ohms the lights might become very dim or quit working all together.

Here’s a bit of text from a manual ( Understanding LED drivers,

“According to the NEC (National Electrical Code), LED drivers should be paired with LEDs that use 20% less than their maximum rated wattage (with the exception of AC LED drivers). Drivers should not be paired with an LED that is at or exceeds the driver’s maximum wattage to avoid overstressing the driver components. For example, if you have a driver that can operate a maximum of 96 watts, it should only operate LEDs that use 77 watts at most (96 x 0.8 = 76.8).”

This sounds like it’s telling us to go ahead and use the much higher wattage driver. But, I think you’re talking about replacing two of them with one. If it’s wired in series it will lower the voltage output, if it’s wired in parallel, it will lower the current.

Hope that didn’t confuse the issue more. If it was me, I would have to rewire the entire circuit to make it do what I want without losing something.


Yup, what old goat has stated is exactly correct. Most LED systems actually only use about half the actual watts they claim their system is rated at. They like to say 300 watts because it uses 100 x 3 watt LEDs but in actuality when you plug it into a wattage usage meter it will show you it only is really using about half, or in your case even less at only about 90 watts. So no you do not want to use two 150 watt drivers unless you want the LEDs to burn out on you very fast. If you want to figure out the math you could potentially run each strip with the properly matched 75 watt driver, all things like ohms, amps and volts need to be taken into consideration to have an actual watts being used of about 150, but even this when done correctly might cause LEDs to burn out sooner than they should. Your system was likely designed around the drivers it is using and any changes could make it inoperable. True wattage usage is one of the things I look at when shopping “off brand” LEDs as an indicator of overall quality and performance. I wouldn’t worry about it too much, it would likely be cheaper and more reliable to just buy another low powered 300 watt system to double your light intensity rather than trying to rebuild the one you have with expensive new internal parts.


Hi all, sorry for late reply I’ve had problems logging in.
Thankyou for your replies! I purchased 2 vipar c2x2’s and im going to use the generic LED panels i have for side lighting hopefully it works well! But unfortunately i am still waiting for my replacement seeds (2 months so far)so if they are still in the post they will probably be stuffed by now! But thanks for replying, can anyone recommend a reliable seed bank that ships to Australia?

Cheers, Brendan.


I’m thinking of buying a xl750 kind grow light , what are your suggestion ?