batterry questions

[dav]

I have some questions about batteries.
once again, i dont know if this is the right place to post in or
if there already is a thread on this somewhere. If there is give me link

#1 can LIPO batts be drained all the way?
#2 can other rechargeble non LIPO batteries be drained all the way?
#3 what is mah? i know ma is milliamps.

thanks for all the help

 

[Bionic-Badger]

1) You usually can, but it's not good for them.
2) Try NiMH batteries. As with all batteries, you don't want to over-discharge them, which can damage the battery.
3) MilliAmp-Hours. Combined with voltage, it's a measure of energy capacity in convenient units that allow you to gauge how long your battery will last at a given current output.

 

[jonasa0601]

Bionic-Badger

If i got a battery where it says "3.7V 1000mAh" it will last at the current 3.7V for 1000hours?? That isn't true. Can you explain?

 

[john_lawson]

read this
it shows a 1000 ma batt subjected to 1000 ma drain  would last only 1 hour
http://rechargeablebatteryinfo.com/rechargeable-battery-terminology.php

 

[jonasa0601]

Thanks John. But what has that to do with the voltage?

What can the voltage sign on an item in your home tell you? (How much it needs ofc, but what does it tell about your item since it needs the amount it does. Lots of things needs 220V, why?)

Sorry for using this thread, but i was just wondering

 

[dav]

thanks for the help guys

 

[john_lawson]

usually a higher voltage unit draws less amps saves money
most electric motors at my work are 460 volts although they can be wired for 220/240 we usually don't run them that way
what exactly are you asking i'm far from a electrical technician maybe others could jump in and help here :-?

 

[rocketparrotlet]

Bionic-Badger

If i got a battery where it says "3.7V 1000mAh" it will last at the current 3.7V for 1000hours?? That isn't true. Can you explain?

No. It would last for 1 hour at 1,000mA. Or 2 hours at 500mA. At least in ideal circumstances, which don't exist. But that's the basic idea, anyways, and it shouldn't be too far off from that.

-Mark

 

[jonasa0601]

John Lennon

Okay, so if the voltage is higher, the amps are more effective? If it has high voltage, the amps are "tight" or what? Like consentrated I hope you know what i mean.

 

[Bionic-Badger]

You should probably read up on it from a website dedicated to the topic. Volts and Amps are two different things. Combined, they produce power. They are also related through resistance and Ohm's law Voltage = Current * Resistance. The best analogy is the water analogy: voltage is like the potential energy the water has from one point to another (how high up it is relative to another point), and current is how much flow there is at a given point (how fat the pipe would be to transport that water between the two potentials). Resistance would be like turbines in the pipe that slow down the flow, producing power. Even a pipe without turbines (a wire) has resistance, though very small. The greater the voltage difference on either side of the resistance, the greater the current.

The 120V and 220V mains in your homes are alternating current (AC), not direct current (DC). DC is what most lasers run on. Unlike DC, in AC there's no "+" or "-" because the current is alternating back and forth. This is why you can plug most devices into the wall without needing to worry about plug "polarity." Some plugs do make a distinction between the two prongs. There is a distinction, which you can read elsewhere; however, it is not like "+" and "-" on a battery.

How do you use AC? Well, you can convert it to DC and use it. Then you'll have current flowing in one direction. You can also take advantage of the alternating current to do things like spinning a motor, since the motor alternates as well. Or maybe you could power a light bulb, since the tungsten filament acts as a resistance and will produce heat and light so long as there is current.

 

[jonasa0601]

Bionic-Badger

I've read on the voltage-amps-resistance for hours, but i don't understand it. At my age i'm good at english, but maybe i need to read it in danish to understand it? It pisses my off
I guess i'll ask a teacher at my school. :/

 

[Bionic-Badger]

Well when in doubt, just trust in the knowns (laws, etc.), even if they seem not to make sense. It's even more "odd" with semi-conductor devices because they can produce specific conditions which may not seem "natural" in a circuit.

A good place to start is to analyze the DDL laser driver. The regulator forces a voltage drop between two pins, and you can figure out what the current will be based on only that and the resistances.

 

[RA_pierce]

Example:

1000mAh battery
/500mA current draw
= 2 hr approx. battery life per charge

1000mAh battery
/1000mA current draw
= 1 hr per charge

Just divide the mAh rating by the amount of current your device is pulling and that should give you a rough estimate of how long your battery will last.

 

[33846]

About 4 months ago it was VERY hard for me to understand ohm's law, voltage, amps, resistance, and every other electronic device, but i just read it over and over again until i got it. now I can build DDL drivers and other little devices, just don't give up you will get it eventualy.

 

[dav]

one more thing-
if i have a charger for 3.6v batts, can i use any batts that are 3.6v regardless of mah?

 

[Bionic-Badger]

Yup, you can. They'll just generally charge faster.