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I am making a robot with the following components:

Here's my power calculation:

enter image description here

Note that the current for the DC motors I used is the current under maximum efficiency from the table in the datasheet. Should I be using this or the stall current which is much higher? Could someone please verify the power calculation? Also, if the power calculations are correct, any advice in terms of picking a power supply. I am thinking of using LiPos that would give something like 30Wh.

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    \$\begingroup\$ Your 'thinking of' number of 30 Wh sounds suspiciously like your 'total power' plus a bit. Note that W and Wh are dimensionally different units. Wh is used to compute run time. W is used to compute power consumption. You need your power supply's peak power output to exceed the peak power consumption of your loads. You need your power supply's Wh to exceed the product of the average consumption of your loads, and your desired run time. \$\endgroup\$ Commented Aug 6, 2024 at 5:37

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A lipo is a good choice for this. It's likely that your motors can both stall sometimes, or at least draw very high current for short periods of time. Your power rail will need to handle that. Luckily lipos can provide enormous burst current. Look at the burst C rating. You can easily find one as high as 50C, which is 100A for a 2Ah battery!

The table you posted is more like what you might use for a battery life calculation; but it won't be accurate for that either. The raspberry pi will not always draw 3A, and the motors will not always be running.

You will want to calculate the worst case burst current, and make sure your circuit and battery can handle it. For the battery, look at the the C, and burst C ratings.

You will also want to calculate the average power required. You will need to estimate the pi's usage given it's workload, as well as how much the motors will draw on average, and at what duty cycle. Once you've done that you can make some battery life estimates to determine how many watt hours your battery will need. You should also check against the C rating, but it's unlikely you will exceed that.

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