Dear Sir/Madam,

I have a full charged 24V 12AH battery, I want to discharge it quickly, is there any simple stuff I can home make and discharge it? I have a 24V motor but I don't want to damage it for too much of time.

Best regards,

Kelvin.

 

Put a load on it. A simple one can be power resistors. Take care not to discharge too fast or too low.

 

First question - why?

Beyond that, one power resistor will do the job. On the datasheet for the battery, look up the maximum discharge current and use Ohm's Law to calculate the resistor value. then use Joule's law to calculate the peak power. Use a resistor with at least twice the power rating.

A more rapid way is with a constant-current load circuit, usually an opamp and a power transistor. The transistor will need a large heatsink, possibly with a fan (which can be powered by the battery).

As above, discharging the battery to too low a terminal voltage value can damage it, or at least reduce its energy storage capacity. If you cannot monitor the battery during discharge, a small comparator circuit can disconnect the resistor when the voltage drops to an unsafe level.

A dual opamp such as an LM358 can perform both functions.

ak

 

As AK said, Why?
Are doing some kind of life-cycle test on the battery?

 

Go to an automotive parts supply store and get two 12V headlight bulbs. Wire them in series for a 24V 100W load.

Or get a dual beam headlight bulb and connect to the low and high beam filaments in series (no connection to the common pin).

Note: the lamp will be very bright and very hot.

 

Or get a dual beam headlight bulb and connect to the low and high beam filaments in series (no connection to the common pin).

That will likely blow the high resistance filament, since it will have more that 12V across it, especially since the low resistance filament will have a lower resistance than rated, carrying less than rated current.

 

Curse you, Georg Simon.

ak

 

Curse you, Georg Simon.

Not fair to blame the messenger.

 

I have a full charged 24V 12AH battery, I want to discharge it quickly, is there any simple stuff I can home make and discharge it?

Make nichrome or even iron wire spiral with required resistance
and put it to distilled water filled jar for cooling.

 

Connect it to an AC Power Inverter and plug in your TV, fan...ect. Enjoy your favorite tv-show!!

 

I discharge the battery because I need to change the connector but I don't have any good discharger at home.

@iimagine, sound good idea but what is AC power inverter? As I know the TV, fan require 220V AC input, my baterry has only 24V.

 

It converts your DC power to household AC power
Google 24V DC to AC Power Inverter

 

I discharge the battery because I need to change the connector but I don't have any good discharger at home.

What connector? You do not discharge a battery to change a connector. Change the connector. Just don't create a short while doing so.

 

Dear Sir/Madam,

I have a full charged 24V 12AH battery, I want to discharge it quickly, is there any simple stuff I can home make and discharge it? I have a 24V motor but I don't want to damage it for too much of time.

Best regards,

Kelvin.

@Kelvin Lee
It is rarely a good idea to fully discharge a battery. The battery life will be shortened or ended if you discharge it too much. Just be careful and do as @MrChips suggested.