DC Boost Converter, XH-M411 DC 3-35V to 5-45V Output Voltage, Adjustable Step Up Voltage Regulator Module for Solar Panels

Used this with a laptop charger to bring back a dead Ryobi 40v battery. It worked perfectly and saved me a ton of money on buying a new battery.

These work great. I've boosted 25.6v to to 36 volts without any issue. Order with confidence.

Arrived damaged, the Heatsink was knocked off the circuit board. Other than that it worked fine, just needed to be repaired.

Works as advertised.

I bought this to run 48 V lights on my 36 V golf cart. It worked perfect. Very easy to install and the lights went from down to bright. Would buy it again if I had to. Love the low good price as well.

This seems well made but mine arrived in very minimal packing and the heat sink had gotten knocked off. If you have some heatsink paste/glue that's not a big deal (unfortunately I don't). More importantly, in testing it out I find it has a very dangerous behavior: if the input voltage falls to the range of 3.0 - 3.5 volts, the output jumps way up to 30 or even 50 volts! A moderate load (100 mA) seems to prevent this. I know it's not designed for that input voltage range but one hopes that if the input is too low it stops working in a benign way. I can imagine lots of situations with a light load and a battery running low where this behavior would be unexpected and disastrous. I read many reviews of another similar device with the same kind of behavior so I don't think this is my mistake or a faulty device. I think this is a design error.

Used to boost a rechargeable battery pack for testing purposes. Works as expected. Pulsating power output light probably due to small output from transformer.It brought the power pack back to life.

I have a 48V computer fan that I needed to use for a project. I bought this to boost the voltage from 12V to 45V. I'm actually running it about 40V and it works great. The fan consumes about 400ma and the total current draw from the 12V supply is about 1.2-1.5a total. It's about 1.2 when the fan is running steady but spikes to 1.5a when I power up the fan. That's certainly reasonable for this powerful of a fan. I'm happy with the product and would not hesitate to buy it again.