how many watts is my 3 amp charger?
- Thread starter recumbent
- Start date
recumbent
100 kW
JS Tyro said:
I double checked my charger after a long ride and it still reads only 11 watts of power. This is my light duty, 3amp charger that i carry with me on my bike.
This meter is a generic brand "UMP" meter and indeed can be inaccurate at lower wattages.
Our electric cost here in B.C. Canada is 6cents per KW/H, but get a discount if payed a week after bill is recieved, which we all do with ebanking ofcourse.
Sorry if my numbers are wrong, but i still don't know what is correct.
julesa
10 kW
- Joined
- Jun 23, 2008
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- 950
11 watts? I think your watt meter isn't working right.
How long does your charger take to give your battery a full charge, 6 or 7 hours?
48v x 12Ah = 576 watt-hours
576 watt-hours / 11 watts ~= 52 hours
I bet it takes a lot less than 52 hours to give you a full charge.
How long does your charger take to give your battery a full charge, 6 or 7 hours?
48v x 12Ah = 576 watt-hours
576 watt-hours / 11 watts ~= 52 hours
I bet it takes a lot less than 52 hours to give you a full charge.
Yeah 56x3 is 167w. So your AC charger at the plug is drawing 11 watts because 110x1.5 is 166 watts hmmm perplexing I say.
I call shenanigans! What if your charger is a 24v at 3a? That would be 72w. What if it is 12v at 3a that is 36w. Lets just say that the portable charger is actually what the numbers say 11w. I bet that your charger is 56v at .3w hmmm naw that would be 50ish watts. i = e /r, e = i * r, p= e * i, ohm made it easy for us. So when your out recharging in public it will take you 52 hours
The connector you use to connect the charger to the battery is broken?
I call shenanigans! What if your charger is a 24v at 3a? That would be 72w. What if it is 12v at 3a that is 36w. Lets just say that the portable charger is actually what the numbers say 11w. I bet that your charger is 56v at .3w hmmm naw that would be 50ish watts. i = e /r, e = i * r, p= e * i, ohm made it easy for us. So when your out recharging in public it will take you 52 hours
The connector you use to connect the charger to the battery is broken?
This is completely absurd. Lets say you actually draw 11 watts that is about two nightlights of power.
For example 110v x .1 = 11 or 56x.2 So you have to have 285 ohms of resistance in the path to your 3 amp charger.
Plugging some numbers into a ohms law we get for example resistance = voltage / current. So 56/3 = 18ohms. Lets say you have 18 ohms of resistance in your path. Power equals current squared times resistance. So 3x3x18 = 162watts. If you are only drawing 11 watts you have to have about 285 ohms of resistance.
One ohm is the resistance value through which one volt will maintain a current of one ampere.
Damn, how is there 285 ohms of resistance between your charger and your batteries is more the question?
For example 110v x .1 = 11 or 56x.2 So you have to have 285 ohms of resistance in the path to your 3 amp charger.
Plugging some numbers into a ohms law we get for example resistance = voltage / current. So 56/3 = 18ohms. Lets say you have 18 ohms of resistance in your path. Power equals current squared times resistance. So 3x3x18 = 162watts. If you are only drawing 11 watts you have to have about 285 ohms of resistance.
One ohm is the resistance value through which one volt will maintain a current of one ampere.
Damn, how is there 285 ohms of resistance between your charger and your batteries is more the question?
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