[brightside]

Thus, to find amps substitute the volts and watts in the formula:
Current_(A) = Power_(W) ÷ Voltage_(V) [links]

[numlock1982]

Convert volts to amps by entering the voltage and the electrical power in watts, or the resistance of the circuit.

[Babylon]

amps = watts ÷ volts
amps = 100 W ÷ 120 V
amps = .83 A [links]

[maniexx]

Watt’s Law states that current = power ÷ voltage. Power is measured in watts and voltage is measured in volts. [links]

[Tilka]

Voltage is the potential difference in an electrical circuit, measured in volts. It might be easier to think of it as the amount of force or pressure pushing electrons through a conductor. To convert volts to amps, a measure of current, it’s possible to use a formula defined by Watt’s Law. [links]

[Anaxagoras]

Amp-hour ratings are how manufacturers rate a battery's electrical capacity, in the same way you might rate a bucket's water capacity in gallons. Manufacturer amp-hour ratings are helpful when comparing different batteries and different brands, but be forewarned: all isn't necessarily what it appears to be on the label.

[friendsofkim]

Manufacturers test and rate batteries according to a certain discharge time -- in the automotive industry, usually 20 hours. In theory, that doesn't affect the actual amp-hour rating, but it does make a difference on how long your battery will last if you consistently discharge it outside of that 20-hour parameter. If you're using a standard battery rated for a 20-hour discharge, and you routinely kill it in an hour with a banging stereo, or 150 hours with a tiny trunk-light bulb that won't shut off, then the battery won't be long for this world. [links]

[mcmoneysack]

In theory, you can calculate the run-time for any of your battery's accessories by dividing the amp-hour rating of the battery by the amp draw of the accessory. You might have to convert from watts first. For instance, if you want to know how long you can bang a 1,000-watt stereo system on a heavy-duty 100-amp-hour battery, start by dividing the wattage by the voltage -- 12 volts, in this case -- to arrive at an 83.3-amp draw for the stereo system. Divide the battery's 100-amp-hour capacity by 83.3, and you get 1.2 hours, or about 1 hour and 12 minutes of tunes before the battery dies.

[siudit101]

David Deane I have a question. I want to run a 4000#winch from a portable battery. The winch sucks 240 amp and would run for 20 min max. Should I use a deep cycle RV battery?? and at what AM- HR rating??

[yebyen]

Kindly shed light on my query. If i have a 12V inverter system, using a 1* 200AH battery and a 48V inverter system which requires 4*200AH battery to get the system to perform. For the 48V system, is the amp hrs calculated as 800AH (4*200ah) or is it still only 200AH since it is connected as a 48V?

[ploum]

Alex I have a small 12 volt, 2.5 amp cab fan. I need to know what type of 12 volt battery to run it for up to 8 hrs at a time. here

[Prado]

BatteryStuff Tech /kb/articles/battery-articles/battery-bank-tutorial.html [links]

[jontaylor]

It isn’t good to run a battery all the way down to zero during each charge cycle. For example, if you want to use a lead acid battery for many cycles you shouldn’t run it past 80% of its charge, leaving 20% left in the battery. This not only extends the number of cycles you get, but lets the battery degrade by 20% before you start getting less run time than the design calls for

[LaidBack]

Account for the efficiency of the inverter, say 85%

[MYurong20]

Thus you would need a 50 amp hour sealed lead acid battery to run the amplifier for 1 hour at 20 amps average draw. here

[DanielLeerasiri]

20*1/3600 + 0.1(3599)/3600 = 0.1044 amps average current. [links]