I'm newbie here. Working with an ESP-09, because of its size. I'm just making it show some text on an OLED screen and handle a few buttons. It's my first time messing around with LiPo batteries, and I've heard they can be a bit risky if you don't use them right.
Saw this post and honestly, it's a bit confusing. It seems like a hassle to have a charger, a regulator, and a load sharing circuit all in one.
So my plan is to hook up my LiPo battery with a connector to a regulator and run my circuit as usual. My setup isn't doing anything critical, so I don't mind if it cuts out suddenly or doesn't show battery levels. I just want to get it working. When the battery runs out, I'll just unplug it and connect it to a separate charging circuit untill it's charged. And then Rinse and repeat.
Does this sound like an okay approach, especially to avoid dealing with load sharing?
Also, I'm trying to decide between a linear or switching regulator. I know linear ones can get hot, And switching ones have more noise. But is that a big deal for this small of a scale?
And one more thing. Got any tips on charging modules? ChatGPT suggested these two: MCP73831 Module TP4056 Module
Would love to hear your thoughts and suggestions to help me figure this out. Thanks!
I think your system will work ok, but with a few caveats. What kind of battery will you be using? You don't want to be removing the battery from a holder because that opens up the possibility of putting in it backwards, which could blow your circuit. So you want a connector of some kind that can't be connected backward.
The TP4056 module has battery protection built in, but if you'll be disconnecting the module to run the device, you still need protection for over-discharge. So you may need to use a protected battery. You could leave the TP4056 module connected to the battery all the time, and just plug in the external USB power when you want to charge. Then an unprotected battery would work fine. You may not need power sharing depending on how much current your project draws. Do you know what that is?
I've used many TP4056 modules, and they work fine. I don't know about the other one, except that it only charges up to 500mA. The TP4056 does 1A by default.
I don't know how much headroom a switching buck converter would need. You'll want to operate down to maybe 3.5V battery voltage, and if it were me I would use a very low dropout linear regulator. The MCP1700 goes up to 250mA, which might be enough for an ESP8266.
I'm using a LiPo AS501235; 3.7V; 160mAh; 0.592Wh, but I might switch it up later. I'm planning to fix it inside the casing with the battery connector easy to get to. This way, when it's time to charge, I can just unplug it and hook it up to my charging module. The module will be its own thing, separate from the main case, and I'm not worried about how big it gets.
Also I use an OLED SSD1306; 0.91"; 128x32 and few buttons. It's going to display text or images that change when you press the buttons. I'm not sure how much current it's going to need, though.
As I said I'm newbie, so sorry if I'm asking something obvious.
So I guess I need a linear regulator to go from 3.7V down to 3.3V, and something to stop the battery from over-discharging? Is there a way to combine these two things? Also, can I charge the battery with them still connected? Like, could I connect the battery to an over-discharge protector, then to the regulator, and have that go to the battery connector? Then, when I need to charge, just plug the connector into a TP4056 module and charge it all up, even with the protector and regulator still hooked up?
Is there an MCP1700 module? As I don't know if I could use just MCP1700 and how? Something like a linear regulator module seems easier for me since you just connect pins you need and that's it.
What will the ESP-09 be doing? Will there be any radio activity?
The display will probably use up to about 8mA depending on how much of the display is populated, plus a bit more when transferring data to it. But the ESP8266 could use many times that, depending on what it's doing.
That's a very small battery. You'll have to change the charge current setting on either charger to get it down to a reasonable level. But lithium polymer batteries are typically protected, so you shouldn't have to worry about that.
I'm not going to try to teach you electronics here. You need to watch a lot of Youtube videos on this stuff. Here's one that looks relevant
That 100 mA or so peak that you see for the ESP is really that: peaks, lasting milliseconds. That's why you need a 100 uF cap for decoupling placed close to the power pins of the processor. A 250 mA regulator is indeed enough.
For battery charging there are cheap ready-made modules available.
Also consider a LiFePO4 battery. The voltage output of those can be used with an ESP8266 without regulation (nominal 3.2V, fully charged 3.6V which is the upper limit of the ESP).
@ShermanP Thank you for the insights, really appreciate you sharing your knowledge. I'll definitely educate myself further on the things you mentioned. However, given my current knowledge and the time it'd take to learn everything properly, I think I'm going to pivot to a different solution for now.
I'm switching to a 3.2V LiFePO4 AAA 10440 280mAh battery. This should allow for a direct connection to the 3.3V? It also fits the size requirements and I'm working on making it easily removable from the case for recharging. I'm using Lii PD2 charger.
What do you think about this new alternative?
Hopefully, one day I can revisit this problem.
