L298m Module power enquiry

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Dears,

hope you all having nice time.

I'm making a joystick controlled 4WD car(4 motors) using AVR and L298m module. when I power the L298m module with 12 v it works perfectly. but i tried to use 9v battery, it didn't work. the module red LED gets weaker when i'm trying to move the car and no motor rotates (the motor just ticks for once). and I already saw projects using two 18650Li-ion batteries which equal 7.4v.

 

what I missed? and is the battery type matters in such projects?

 

thanks

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Last Edited: Fri. Dec 13, 2019 - 08:43 PM
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9V batteries are miserable little buggers. One simply cannot supply the power needed to run 4 motors and they drain really fast when they do. 9V batteries are intended for applications that need a few milliamperes or a little more. That is your problem, not the control module. It would be the case with ANY control module because the problem is the battery.

 

18650 batteries can deliver a LOT of power. They are much more suitable for such a project.

 

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

Last Edited: Fri. Dec 13, 2019 - 08:40 PM
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Thank you sir for you quick reply, it was a helpful answer

 

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9V batteries are about the worst on the planet...there is no capacity, since most of the battering is metal casing, separating all the individual cells....even 2 AAA batteries probably has more energy than a single 9V battery.

The L298 is also a rather horrible driver, since you toss out several volts into the trashcan & you are only starting with 9 or 5 or 12V.  Use a mosfet driver & toss more like 0.2 V or maybe 0.5 V into the trash.  Why waste your battery power on just heating up driver chips?
Take a look at DRV8871 or other such chips.   TB6612  as well (avail from sparkfun too)

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