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Adafruit Motor Shield V2.3-Power Supply and Motor Ratings
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Adafruit Motor Shield V2.3-Power Supply and Motor Ratings

by bodat86 on Mon Sep 28, 2020 11:16 am

Hi AF!

I've searched posts in this category but I'm not finding answers I need. Two questions:

1) I'm using 2 DC motors from Pololu. Their rating is 12V, 80 mA, stall extrapolation is 1.6A. Will the shield work for them? From what I've read, the shield will work. Just checkin'.

2) I'm powering the shield with 6 AA (9v) alkaline for prototyping. I would like to use rechargeable Lithium batteries. I was thinking 4 ea. 3.7v, making 14.8v. Or shall I use 3 making 11.1v? Can the shield take that voltage? If not, any suggestions?

Thanks!
Bo

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Re: Adafruit Motor Shield V2.3-Power Supply and Motor Rating

by adafruit_support_bill on Mon Sep 28, 2020 11:43 am

The datasheet for the driver is here: https://cdn-shop.adafruit.com/datasheet ... 121101.pdf

1) I'm using 2 DC motors from Pololu. Their rating is 12V, 80 mA, stall extrapolation is 1.6A. Will the shield work for them? From what I've read, the shield will work. Just checkin'.

It will work if you don't stall the motors. The continuous current rating of the TB6612B drivers is 1.2A. They do have a 3A 'peak' rating, but that is only for very brief peaks of a few milliseconds - such as during motor startup.

2) I'm powering the shield with 6 AA (9v) alkaline for prototyping. I would like to use rechargeable Lithium batteries. I was thinking 4 ea. 3.7v, making 14.8v. Or shall I use 3 making 11.1v? Can the shield take that voltage? If not, any suggestions?

14.8v is too high. These chips are rated for an operating voltage max of 13.5v. Also note that your motor ratings are based on a 12v supply. If you increase the supply voltage, the current draw will increase proportionally as well.

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Re: Adafruit Motor Shield V2.3-Power Supply and Motor Rating

by bodat86 on Mon Sep 28, 2020 12:24 pm

Thanks Bill!

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Re: Adafruit Motor Shield V2.3-Power Supply and Motor Rating

by carloseflores on Wed Oct 28, 2020 11:22 am

Hello,

I have some similar questions.
I want to use two 1.3A motors connected to the Motor Shield V2.
Is the 1.2 amps a limit per motor or for the whole shield?

Considering that the limit of 1.2 is per motor, can I get away with the two 1.3 motors using a heat sink in the chips? Or should I limit the motor to ~80/90%?

Thank you!

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Re: Adafruit Motor Shield V2.3-Power Supply and Motor Rating

by bodat86 on Wed Oct 28, 2020 12:40 pm

Hi all,

I got around this issue(s) by using 12V motors (lower amps) instead of 6V motors, and a 12V buck/boost converter. No matter my voltage input, I get 12V out.

bodat86
 
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Re: Adafruit Motor Shield V2.3-Power Supply and Motor Rating

by adafruit_support_bill on Wed Oct 28, 2020 12:42 pm

The limit is 1.2A per motor. But if you will be driving both channels at that level for extended periods, a heat-sink would be a good idea.

I want to use two 1.3A motors connected to the Motor Shield V2.

A current rating without a specified voltage and load is meaningless. Motor specs usually include a recommended supply voltage, a 'no-load' current and a 'stall current' rating. Both current ratings are valid only for the specified supply voltage. If you change the supply voltage, the current draw will change proportionally.

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Please be positive and constructive with your questions and comments.