powering arduino and Motors with a 3S lipo battery .

Using Arduino General Electronics
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hello ,

i have a 3 Cell lithium-ion battery (3 3.7V Li-Ion cells hooked in series) connected to a BMS(battery management system) (this one : BMS ) , to power the arduino , i connected the Battery to a DC-DC 5v set buck converter (this one : buck ) , the Arduino works well .

now aside from that , i am powering 2 kinds of motors , 5v motors and a 12v motor .
for those , the 11.1v output(when fully charged) of the battery is directly connected to H-BRIDGE chips (L293) controlled by the arduino . operating a 12V motor with a 11.1V supply is as far as i know acceptable , and when it comes to the 5v motors , they are all controlled via a PWM arduino signal with a 50% duty cycle , therefore the voltage never goes beyond 5.5v on their rails .

now the problem is here : as the battery loses charge , the voltage goes from 11.1v to around 8v then 7.5v , the voltage on the 5v motors will therefore become around 3.7v , and on the 12v motor around 7v , the current therefore becomes higher . i did read online that that might get the motors to overheat and therefore go bad over-time .
do i have a problem here ? and if do , how can i fix it ?

thank you very much

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The L298 driver will drop 2 to over 4V, by itself, due to the bipolar output transistors (depending on current). You might want to look at some of the modern MOSFET output drivers available from places like Pololu. Google "pololu dc motor drivers".

What is the capacity of your battery (mAh)?

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groundFungus:
The L298 driver will drop 2 to over 4V, by itself, due to the bipolar output transistors (depending on current). You might want to look at some of the modern MOSFET output drivers available from places like Pololu. Google "pololu dc motor drivers".

What is the capacity of your battery (mAh)?

thank you very much for your attention sir , i am very sorry for responding this late i had an urgent obligation .

for my lithium ion cells , the capacity is 2C , and the capacity is 2600mAh , the manufacturer indicated that the maximum discharge current is 5A , yet my BMS has a cut-out of 4A .
so the maximum discharge is around 4A i guess .

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