Continue to Site

# [SOLVED]wattage conversion question

Status
Not open for further replies.

#### Manny the Manny

##### Newbie level 2
I have made a parallel circuit that supplies power to three Noctua NF-A4x10 FLX
Premium Fans (each has an input of 12V/5A/0.6W). I wanted to use a 12v 5000 mAh UPS Battery (SLA1055). The problem is that when I tried to look up the output wattage using various online calculators, it has a 60 Watt output. I want to know if:
B.)Is there a way to reduce the wattage?
C.)Any battery recommendations?
Image to simplify:

First of all, 12V at 5A is 60W,not 0.6W. My guess is you read something wrong, and its .05A, not 5.0A.

Second of all, the battery will only put out as much power as is required, NOT its rated maximum.

Thirdly, I don't know how you calculated a 60 Watt output from the battery. Just because it's a 5000 maH battery, doesn't necessarily mean it will put out 5 Amps for one hour any more than it means it will put 5000 Amps for 1000th of an hour. You need to look at the data sheet for the battery to determine its maximum output current.

Manny the Manny

### Manny the Manny

Points: 2
Thanks, I'm self-learning electronics so the clarification is very useful. Thank you for helping me with the most detailed and effective response I have ever had!

Wow, I'm flattered!

Yes, that's a common misconception among noobies, that a power source will put out it's rated power regardless of the load. But think of it in terms of your house: you probably have service for something like 100 amps at 120 V (or maybe 240, depending on where you live). That doesn't mean you're cellphone charger is going to have to dissipate 12000 Watts. (Let's hope not...)

Status
Not open for further replies.