Timeline for How can I use two 18650 cells with a 5 V, 4 A load?
Current License: CC BY-SA 4.0
19 events
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| Mar 28, 2023 at 16:36 | history | edited | ocrdu | CC BY-SA 4.0 |
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| Mar 28, 2023 at 14:10 | answer | added | winny | timeline score: 1 | |
| Mar 28, 2023 at 13:56 | comment | added | winny | Draw a schematic and/or block diagram with your attempt? | |
| Mar 28, 2023 at 13:55 | comment | added | Stremon | I understood that the first time you said, thanks. It doesn't help one bit to figure out how to connect and use both at the same time in a safe way, which was the whole meaning of my question here. But if you don't know you don't know. | |
| Mar 23, 2023 at 7:17 | comment | added | winny | As I said, buy one to do the charging. Buy another to do the 5 V output. | |
| Mar 23, 2023 at 4:07 | comment | added | Stremon | ok, that I understood the first time, my question is: how? | |
| Mar 21, 2023 at 21:27 | comment | added | winny | That’s the trick, use two parts. | |
| Mar 21, 2023 at 19:34 | comment | added | Stremon | ok I looked into it, sadly it doesn't really help for my questions haha How do you split up the charge and discharge, and what kind of component to I need to regulate the 18650 charging and have a proper/safe 4A discharge? Dealing with the supply, PSU,USB C or other, or buck/boost converting aren't a problem for me. But dealing with batteries is new to me. I only need help with the charging/discharging part, because I cannot find any readily available and well documented circuit that allows to do it at such power. | |
| Mar 21, 2023 at 19:17 | comment | added | Stremon | thanks, I will look into it. | |
| Mar 21, 2023 at 19:12 | comment | added | winny | I see. There is nothing stopping you from making a 5 V 4 A buck converter. Have a look at TI webench, Linear/Analog devices or any other PMIC vendor. To make things easier, split the charge and discharge into two separate parts. | |
| Mar 21, 2023 at 19:06 | comment | added | Stremon | So 4 things there; 1. I wasn't talking specifically about USB at all in my question, beside the power delivery solution, that can be easily covered with a PD emulation chipset (which I already have). Any 5V power supply, even one with a DC barrel, will do. 2. while USB C PD, quick charge or other similar standard have power negociation, the generic USB power supply are nothing more than 2 wires. 3. the devices I want to power only have VCC and GND, nothing else. 4. the power supply part isn't a problem, my question is only about the charging/regulation side of things. | |
| Mar 21, 2023 at 15:18 | comment | added | winny | Does not matter. You still need power negotiation per port. | |
| Mar 21, 2023 at 14:54 | comment | added | Stremon | I am not talking about PC USB here, there is no data, only power. USB chargers can go way over what standard USB-A do. Same with externally powered USB HUB. | |
| Mar 21, 2023 at 14:43 | comment | added | winny | That’s because of the USB-A limitation. You need to provide a 2 A handshake for each output. 4 A isn’t allowed over USB-A. | |
| Mar 21, 2023 at 14:41 | comment | added | Stremon | Thanks for the answer. Yeah I plan to power 2 usb devices that each take a bit less than 2A. Afaik we can boost voltage but current is only relative to what the charger can provide, and since most charging circuits are limited to 1 or 2A, I can't find what I need sadly. | |
| Mar 21, 2023 at 9:55 | history | edited | JRE | CC BY-SA 4.0 |
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| Mar 21, 2023 at 9:35 | comment | added | winny | Welcome! I would prefer 2P configuration in order to not have to bother about balance charging. Regarding 4 A not available, most offerings have 2 A USB-A in mind but there is nothing stopping you from bucking or boosting to 5 V and 4 A. Do you plan to use USB-A outputs or something completely different? | |
| S Mar 21, 2023 at 9:28 | review | First questions | |||
| Mar 21, 2023 at 15:30 | |||||
| S Mar 21, 2023 at 9:28 | history | asked | Stremon | CC BY-SA 4.0 |