# dc wattage increase

Discussion in 'General Electronics Chat' started by alchemy, Dec 13, 2014.

Dec 12, 2014
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2. ### MikeML AAC Fanatic!

Oct 2, 2009
5,450
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You put in a minimum of 100W, and you will get out a maximum of ~96W.
It will put out 220W if you put in 231W.

Real clever spec sheet writing to make you think that it will put 220W in you only put in 100W.

3. ### alchemy Thread Starter New Member

Dec 12, 2014
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Hi Mike thank you
how can i increase my wattage while using a 100w panel or if i must i will use a 250w panel.
i need to charge 6x 48v batteries while i only use the 1 panel ? the motor is 48 vdc load 1.8kw
Regards Sharon

Apr 5, 2008
15,798
2,384
Hello,

What are you trying to do?
You can charge the batteries with the panel and run the motor for about 1/17 of the time the 100 Watt panel has charged the batteries.

Bertus

Dec 12, 2014
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6. ### MrChips Moderator

Oct 2, 2009
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3,451
Under full load your motor draws 1800W/48V which is close to 40A.

Two solar panels delivering 200W @48V can only supply 200W/48V which is about 4A.

You cannot run the motors from the solar panel. The purpose of the solar panel is to recharge the batteries.
With one 100W solar panel, you need to be in full sun for 20 hours for every hour of run time, or 5 hours of charging for every 15 minutes of run time.

7. ### alchemy Thread Starter New Member

Dec 12, 2014
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Thanks
I have 6x 48v batteries each one been 60w and i have a solar controller, i can you my 120w panel.Can you help me with the formula,
here is a link that i would like you to read please,i am wondering if its true or not ?

8. ### #12 Expert

Nov 30, 2010
16,664
7,311
Formula: watts times hours equals watt-hours.
100 watts times 18 hours = 1800 watt hours.
1800 watts times 1 hour = 1800 watt-hours.

There is no such thing as a machine that can convert 100 watt-hours into 101 watt-hours.
That is called perpetual motion.
The smartest people on the planet believe that is impossible and always will be impossible.

9. ### MrChips Moderator

Oct 2, 2009
12,623
3,451
What #12 means is that you cannot create extra energy from nothing.

Power is measured in watts. Energy is measured in watt-hours.

You can put 100W for 2 hours into a battery.
Then you can recover 200W for 1 hour assuming 100% efficiency.

#12 likes this.
10. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,500
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Have you ever hear about Law of Conservation of Energy?