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Using Arduino => General Electronics => Topic started by: Audiph on Dec 08, 2018, 03:04 am

Title: Battery's Current
Post by: Audiph on Dec 08, 2018, 03:04 am
Just a quick question for y'all. Is there any battery that can give out lots of current? Can a rechargeable battery do just that? I have a 2 dc motor and an L298n driver project. When I tried to run it using 12v AA batteries, it will run but it will stop minutes after. But when I used 2 12v paralleled batteries, It can last longer but not too long :D Any help from you guys will be much appreciated. Btw, here's the specs of what DC motor I used.

DC Gear Motor 12V 178RPM - SGM37-3530
Gearbox: Spur Gear
Rated Voltage: 12V (6 to 12V Range)
Nominal voltage: 12 V
Free-run at 12 V: 178 RPM
Free-run current at 12 V: 120 mA
Stall current at 12 V: 1.2 A
Stall torque at 12 V: 8.4 kg.cm
Gear ratio: 1.56
Reductor size: 24 mm
Max Power: 4.8W
Weight: 200g
Title: Re: Battery's Current
Post by: JohnRob on Dec 08, 2018, 03:25 am
A couple to thoughts:

1) Given the specifications the motor current cannot be determined.   Assuming the motor is turning then the current is somewhere between 120 ma and maybe 1 amp.  The actual current will depend on the load.   Do you have a meter to measure the current.

2) How long are you looking to run for?   Beware if you say "as long as I can" then I would suggest an automotive 12 V battery.

Title: Re: Battery's Current
Post by: srnet on Dec 08, 2018, 09:31 am
You might understand what 'lots of current' and 'it will stop minutes' and 'not too long' means, unfortunatly the forum does not.

If you want help, try to be more specific. 
Title: Re: Battery's Current
Post by: PerryBebbington on Dec 08, 2018, 11:07 am
Just a quick question for y'all. Is there any battery that can give out lots of current?
Have a look at industrial batteries (https://www.batterygiant.com/industrial-equipment-battery/), I'm sure you will find a battery there that will give lots of current.
Title: Re: Battery's Current
Post by: slipstick on Dec 08, 2018, 11:10 am
Yes there are many batteries that can provide "lots of current" and run for a long time. The more current they can provide and/or the longer they can run at high currents the bigger, heavier and more expensive the battery will be.

I'm guessing that 3S (11.1V) lipo batteries may be the sort of thing you need. They come in all sorts of capacities so you can probably choose one that can run those motors for the length of time you need between recharges.

If you want more detailed answers let's have some numbers. How much current for how long?

Steve
Title: Re: Battery's Current
Post by: TomGeorge on Dec 08, 2018, 02:15 pm
Hi,
I have a 2 dc motor and an L298n driver project.
There is some of your problem, L298, you loose up to 2V across the controller because it is old tech.
You need a MOSFET motor driver.
Tom... :)
Title: Re: Battery's Current
Post by: MarkT on Dec 09, 2018, 04:55 am
Your AA batteries may be cheap ones - avoid cheap ones like the plague, many have almost no capacity
at all.

Known, good brand, high capacity, rechargable batteries are the way to go.  Expect to find upto 2.5Ah
in AA size.
Title: Re: Battery's Current
Post by: wvmarle on Dec 09, 2018, 03:54 pm
Proper AA batteries can provide enough current to heat themselves up to the extent the exterior melts. That takes a few minutes, but after that still some charge left.

For motors, rechargable batteries are best. They're good at high current applications, alkalines less so.

For motor driver, consider the TB6612FNG.
Title: Re: Battery's Current
Post by: MarkT on Dec 10, 2018, 01:53 am
Cheap no-brand rechargables are no good though, you get what you pay for, always try to
choose branded batteries for which datasheets exist (yes, batteries have datasheets)...