The datasheet for the L298 motor driver says its maximum DC output is 2A for each of its 2 channels.

 

You don’t add up the voltages of your devices when they are connected in parallel. If you have 2 - 5V motors, then you need 5V (not 10). But you do need to add up the needed current. If each motor needs 1A then you have to supply 2A. If a load needs varying amount of current, then you add the peak current. For motors, the peak current is the stall current.

Current loading is the sum of all currents drawn by your loads (devices). You always need a little more current than the total. Start with 20% more. If the servos are RC servos (model servos), in my experience they need 1A apiece. Those motors may draw as much as 2A. You can measure the current draw with a DMM set to measure current in series with the motor. This varies a bit if everything doesn’t run at the same time. But it gives you a starting estimate.

But a power plan or current loading can use estimated values. Having said that 4x1A * 4x2A = 12A. I left out the ESP32 because it draws a couple of orders of magnitude less than the motors. If the batteries can supply 2.2Ah, then they might last as little as 10 minutes if the supply can supply 12A. Note that Ah is a different unit than amps.

Given your buck converter can supply a maximum of 3A, it’s going to be severely overloaded. Internal protection will shut it down. And then nothing will work. As you have found.

You need to get better estimates of the current required for the motors and do a power plan of your own. Then with this information, you’ll have to design a power supply that will work.

 

Can you tell me what that is? So I can find it

??? This response makes no sense.

 

NOBODY makes an 18650 Li-Ion battery that is as high as 8000mAh so you got cheated with fake batteries.
Name Brand 18650 Li-Ion batteries are 3300mAh maximum. Some cheap ones sold at AliExpress are rated at 19900mAh!

??? This response makes no sense.

I'm sorry

 

How much current can a 18650 produce?

A fake 18650 battery produces nothing or only a tiny current. Here is one:

 

The step down module is lm2596 and is rated 4.5v - 35v to 1.25 - 30v with maximum current 3 amps

I'm using sg90 servos, from the data sheet the stall current is 650±80mA

I don't know what current loading is

The current load is how much current your motors will draw. In particular, the maximum current the might draw. That, plus the needed voltage, is your starting point for determining every thing else. No point picking a motor driver unless it is compatible with the voltage and current requirements of the motor. No point picking batteries until you know what you need the batteries to do.

With nothing better to go on, you can use the stall current as a starting point. The actual draw should always be less than that. So I'd play it safe and design for one ampere per motor (unless you want to actively limit it to a lower value for some reason).

How long do you need this to run on one battery charge? Your first cut could assume that each motor will need 650 mA continuously and see how much battery you would need to support that. If that size and weight of battery is acceptable, you've got your battery chosen. If it's too much, the iterate the design. One approach would be to actually measure how much the motors consume under the expected loading and see if a battery that can support that is acceptable. If it isn't, then you have more fundamental problems to deal with and should start with your current budget by determining what the largest battery you can tolerate is and what your average current draw needs to be below in order for it to last long enough to be deemed acceptable. Then you start looking for actuator designs that fit within that current budget.

 

Can it produce 5 amps?
I have no info of the discharge rate

18650 is basically a battery size. Lots of different batteries from lots of different manufacturers exist with that package size. You need to look at the websites/datasheets for the specific battery you want to use.

But a quick look at a few manufacturers pages shows that continuous discharge currents of up to 20 A are not uncommon.

Keep in mind that a 5 A draw from a 2500 mAh cell will deplete it in about half an hour (which, when you get right down to it, is pretty impressive). Probably quicker, since the capacity rating is likely at a lower current draw, but that should put you in the ballpark.

 

A fake 18650 battery produces nothing or only a tiny current. Here is one:

And a fake 100 lb bag of cement might only weigh 10 lb. So what?

 

The current load is how much current your motors will draw. In particular, the maximum current the might draw. That, plus the needed voltage, is your starting point for determining every thing else. No point picking a motor driver unless it is compatible with the voltage and current requirements of the motor. No point picking batteries until you know what you need the batteries to do.

With nothing better to go on, you can use the stall current as a starting point. The actual draw should always be less than that. So I'd play it safe and design for one ampere per motor (unless you want to actively limit it to a lower value for some reason).

How long do you need this to run on one battery charge? Your first cut could assume that each motor will need 650 mA continuously and see how much battery you would need to support that. If that size and weight of battery is acceptable, you've got your battery chosen. If it's too much, the iterate the design. One approach would be to actually measure how much the motors consume under the expected loading and see if a battery that can support that is acceptable. If it isn't, then you have more fundamental problems to deal with and should start with your current budget by determining what the largest battery you can tolerate is and what your average current draw needs to be below in order for it to last long enough to be deemed acceptable. Then you start looking for actuator designs that fit within that current budget.

Thank you so much for the help

 

And a fake 100 lb bag of cement might only weigh 10 lb. So what?

He showed a photo of his no-name-brand batteries marked with 8000mAh which is impossible then they are probably fake.

 

I110

He showed a photo of his no-name-brand batteries marked with 8000mAh which is impossible then they are probably fake.

It has a brand mitsuyama. When I looked at their website, there's a description all the the way at the bottom with the text "real capacity 1100 mah". I didn't saw it at first.
What does real capacity means, is it different than normal capacity?

 

I110

It has a brand mitsuyama. When I looked at their website, there's a description all the the way at the bottom with the text "real capacity 1100 mah". I didn't saw it at first.
What does real capacity means, is it different than normal capacity?

Maybe "real capacity" is different from "imaginary capacity".

 

I have 3 18650 batteries connected in series, but it's not enough. Can I deliver enough power with 4 18650 batteries?

Please tell us how you determined it is not enough, giving us any data you collected and the conditions under which it was collected.

 

He showed a photo of his no-name-brand batteries marked with 8000mAh which is impossible then they are probably fake.

You already made the point that it was probably fake. That has no bearing on his question regarding how much current an 18650 battery can deliver.

 

I110

It has a brand mitsuyama. When I looked at their website, there's a description all the the way at the bottom with the text "real capacity 1100 mah". I didn't saw it at first.
What does real capacity means, is it different than normal capacity?

The higher number is almost certainly pure marketing hype, but we can't discern what it may or may not mean unless you provide a link so that we can see what it actually says.

 

The higher number is almost certainly pure marketing hype, but we can't discern what it may or may not mean unless you provide a link so that we can see what it actually says.

https://mitsuyama.id/product/baterai-8000mah-li-ion/
Here is the link

 

https://mitsuyama.id/product/baterai-8000mah-li-ion/
Here is the link

My guess is that, if brought to court, they would claim that the 8000 mAh is not any rating at all, but merely part of the model name.

The fact that they are clearly trying to deceive you should be more than sufficient reason to not do business with them -- there is zero basis upon which to conclude that anything they do or claim is legit (and more than a little basis upon which to conclude that it likely isn't).

 

My guess is that, if brought to court, they would claim that the 8000 mAh is not any rating at all, but merely part of the model name.

The fact that they are clearly trying to deceive you should be more than sufficient reason to not do business with them -- there is zero basis upon which to conclude that anything they do or claim is legit (and more than a little basis upon which to conclude that it likely isn't).

Should I just get a lipo battery?

 

That unknown 18650 battery is not a 3300mAh Name Brand like LG or Panasonic.
There are also fake LiPO batteries sold.

I never buy unknown cheap fakes online, I buy LiPO batteries from a local hobby store I trust.

 

Those motors run at 6v and take around 300-500mA depending on how bad the gearbox is. They burn out & die at 9v. Below 4v they have little torque because there is so much friction in the gearbox, so don't expect smooth starts