Can i use acide battery 6v 4.5AH to run 18V DC motor 404 watts

ekonltd

10 µW
i have an old DC motor rated wattage is 404 watts 18 volt it requires about 22 amps
im planing to use acide batteries in series and parallel 6+6+6=18v multiplies by 4 wich give me 18 AH 18 volt but initial current discharge is only 2.1amps
does it effects the life of batteries if so how long does the battery last

what makes me ask this quistion is that bellow
<i see some chines electricbikes using the same batteries but they works and is everywhere cant imagine it till i see them they works on 60 volts DC motors>

amberwolf

Staff member
i have an old DC motor rated wattage is 404 watts 18 volt it requires about 22 amps
im planing to use acide batteries in series and parallel 6+6+6=18v multiplies by 4 wich give me 18 AH 18 volt

Which specific batteries are you intending to use? A link will help the most.

Which specific controller are you intending to use to control the motor output?

but initial current discharge is only 2.1amps
Do you mean the controller is limited to 2.1A?

Or do you mean the batteries are rated to only discharge at 2.1A max?

Or something else? (be very specific and detailed if possible)

does it effects the life of batteries if so how long does the battery last

Do you mean range, distance travelled? That depends on your specific riding and road conditions, terrain, wind, hills, how hard you use the throttle, speed you go, weight of you and the vehicle you're building and anything you carry.

Or do you mean lifespan, how many months before you have to replace them?

what makes me ask this quistion is that bellow
<i see some chines electricbikes using the same batteries but they works and is everywhere cant imagine it till i see them they works on 60 volts DC motors>
I'm not sure what you're asking there.

ekonltd

10 µW
Which specific batteries are you intending to use? A link will help the most.
lead acide batteries 6v 4.5 ah

ekonltd

10 µW
Which specific controller are you intending to use to control the motor output?
im not using a controller its a brushed DC motor

ekonltd

10 µW
Do you mean the controller is limited to 2.1A?
i mean the battery max discharge limited to 2 amps
Or do you mean lifespan, how many months before you have to replace them?
the motor absorb 22 amps but batteries only giving 2 maps per hour in safe conditions thats why i asked if im using them how long does they work till colapsing

amberwolf

Staff member
lead acide batteries 6v 4.5 ah
Ok, then that plus this info:
series and parallel 6+6+6=18v multiplies by 4 wich give me 18 AH 18 volt
means that you have 18v in series (3s, three batteries in series), and 4 x 4.5Ah for 18Ah capacity (4p, four in parallel).

That's a pretty big heavy battery pack, though, since that's 12 lead acid batteries that each probably weigh about a pound and a half each, plus their wiring and whatever enclosure you use for them; guessing about 20lbs total, and probably the size of a medium toolbox.

A link to the actual batteries might help us know more about them and what they are capable of; without that it's safe to assume they can only provide less than half of the total 18Ah rating at the currents your motor will use. That is normal for lead. (lithium would give nearly all of the rated capacity).

im not using a controller its a brushed DC motor
A brushed DC motor usually still uses a controller in these types of scooters.

If there is no controller then that means you only have options for either no speed (stopped) or full speed, and are using just a large heavy switch to turn the motor on and off while riding.

If you have variable speed control of the motor, you have a controller operated by a throttle of some type (potentiometer, or hall, etc).

If so, that controller will have a current limit, which should be marked on it's label. There are some really cheap ones that don't monitor or limit current per-se, but they dont' usually last very long under any serious load.

It would help us help you if you would show us everything you are actually using, preferably with links to where they were purchased if bought online (the info on the pages will help us help you). it would help even more if you also tell us what your purpose is for the project and what exactly you need it to do for you, under what specific riding conditions and terrain, etc. Then we could help you make sure that what you are building will actually do those things for you.

i mean the battery max discharge limited to 2 amps
What limits it to that? The batteries have nothing to limit them and cannot do this.

A motor controller with a 2A current limit could do that, for your application. Such a controller would probably not even be able to move your scooter down the road, though it would probably spin the wheel off ground..

If you mean that they are rated for only that much current, then that means you need to get a motor controller that can only draw that much current, as a 22A-capable motor (or system that draws eleven times as mcuh as the battery is mean to supply) will severely stress the batteries and damage them.

the motor absorb 22 amps but batteries only giving 2 maps per hour in safe conditions thats why i asked if im using them how long does they work till colapsing
That's pretty easy:

2Ah / 22A = hours it will operate.

That would be 0.09 hours, or about 5 minutes.

In reality, lead acid will only give about half the capacity (Ah) it's "rated" for at anything ohter than very tiny currents, so you will probably get (much) less than half of that runtime, so probably about 2 minutes.

However, without a controller, a motor will draw much more than it's label/nameplate shows, if the load is high enough--there is nothing but resistance in the wiring to stop it from drawing infinite amps and burn up.

So with no controller to limit the current, then assuming the batteries can handle the current, and the load on the motor is high enough, you could have less than a minute of operation.

Also, without a controller that has the proper LVC (low voltage cutoff) for an 18v system (around 15-16v or higher), you'll need a voltmeter that you can see while riding so you can stop before you damage the batteries by draining them too far. That's normally around 5v-5.5v for a 6v SLA (around 10-11v for a 12v SLA), so around 15-16v for your setup.

Do you have an ammeter that can measure the actual current in your system? You'd probably need a clamp-on type to measure currents above 10A, though many generic multimeters can measure up to 10A directly. It would be helpful to you to know how many A each part of your system is actually seeing.

ekonltd

10 µW
thanks for all the info i moved to using lithium 18650 batteries they are better at discharge than lead acide batteries
im now in period of testing capacity of each one to generate suitable pack for my needs in help of rePackr - 18650 pack builder
i like the forum also your responses its nice to be here

nicobie

Moderator
Staff member
thanks for all the info i moved to using lithium 18650 batteries they are better at discharge than lead acide batteries
im now in period of testing capacity of each one to generate suitable pack for my needs in help of rePackr - 18650 pack builder
i like the forum also your responses its nice to be here