hi i'm new with esp8266, i want to build smoke detector with all of this component (esp8266 ch304, li-ion battery 2600mah 3.7volt, mq2 sensor, buzzer and a fan ( the fan work well with that battery)), how can i power Nodemcu with that li-po battery, did i need to buy some thing else? (i also have 180k 1w resistor)
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Look-up the voltage specifications of the battery.
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Look-up the voltage specifications of the Nodemcu.
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Do they match?
3a. If yes, you're good to go;
3b. If no, then you'll need some stuff to go between them...
Adding: Check if the fan works well enough from 3.7 volt. Else a stepup converter is needed.
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What is the purpose of the fan ?
I do not see a li-po battery in your picture. I can see a 18650 li-ion battery. These are not the same. Normally, li-po batteries have a protection circuit built-in. Normally 18650 li-ion batteries do not have a protection circuit built in. If that is the case, you will need to buy a protection circuit, otherwise using this type of battery is dangerous. It could itself cause a fire.
This is a li-po battery. You can see the protection circuit under the yellow tape.
This is a 18650 li-ion cell without protection:
With this type, it is important to add an external protection circuit.
This is an 18650 li-ion cell with protection:
The protected cells sometimes have a visible circuit board at the base of the cell, and a metal band running along the length of the battery, which allows the protection circuit to sense the battery's voltage.
Because of the protection circuit, this type of cell is a little longer:
Button top Size approx. Diameter 16.5 x Length 66.7mm
Protected Button top Size approx. Diameter 16.5 x Length 69.3mm
As you can see, the protected cell is 2.3mm longer than the unprotected cell. This can make them difficult to fit into some designs of holder.
This may be difficult. NodeMCU boards have a regulator with a large voltage drop. They may only run when the li-po cell is fully charged, and stop working long before the li-po is empty.
A Wemos Mini is similar to a NodeMCU but better because it is more compact and has a regulator with a low voltage drop, so can continue working until the li-po cell is empty.
the room i work kinda big i need to smoke go in mq2, just make sure that work like i thought
the fan work well with that battery, btw thank for that
this code i use in this link with blynk, it can send message to me went it nearly emty
I advise you to use a protection circuit and not rely on messages. You could miss the message, the battery could be drained too far and become damaged. Then, when you re-charge the battery, it could catch fire.
Because you are building a smoke detector, you should make sure that the detector itself does not cause a fire.
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He's said it twice:
Good.
You can use a combined charging protection and discharge protection module like this:
Take care. The type below look very similar but only protect the battery during charging and don't protect against over-discharging. They are only ok to use with batteries that already have built-in over-discharge protection circuit:
Also available are very small over-discharge protection board like this one:
You may notice this picture is labelled "charger board". It is not. You must be careful because the on-line sellers on eBay and other sites do not understand the technical capabilities of the items they sell. (The same sellers will often sell bikinis and stick-on plastic fingernails.)
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