Hi Hans, Don't make it more complex than it is. An MPPT (Maximum Power Point Tracking) is used on solar panels to get the most out of it but you do not have to add such a device.
If I am right a Lipo battery needs a certain way of charging and so you need a special Lipo battery charger. I made a Cat repellent some time ago using a small solar panel. And since I am using three NiMh batteries (so 3.6 Volt) I use a small charging current for keeping the batteries charged. The batteries are connected to the solar panel only via a diode (Shottkey in this case because it has a low voltage drop). For your info. You can find the schematic diagram here: https://www.instructables.com/Cat-Repellent/ Kind regards, Rob ________________________________ Van: [email protected] <[email protected]> namens hans <[email protected]> Verzonden: woensdag 29 juni 2022 11:22 Aan: jallib <[email protected]> Onderwerp: Re: [jallib] sun power use Such a prompt response! I bought a solar charger with a built-in 5000mAh battery. It delivers a beautiful 5 Volt but with a minimum load of 150 mA. Opened the case and the lipo delivers 3.5 Volts. So I soldered a few more wires to it. Hence my question. It's still so much fun. Now i have to discover what a MPPT is. regards Hans Op woensdag 29 juni 2022 om 09:59:30 UTC+2 schreef [email protected]: Hi Hans, Most PICs can operate at 3 Volt, below a screenshot from the datasheet. I only use F versions. [https://groups.google.com/group/jallib/attach/28f73b2c4d2ca/image.png?part=0.1&view=1] Just check the datasheet for the PICs that you have. I have done several projects using a PIC that is supplied by batteries so operating at 3 Volt or lower. What I do not know for sure if when you program the PIC if it should be at 5 Volt, maybe only if you use Low Voltage Programming, so I normally program the PIC when it is connected to a 5 Volt power supply but in the application it can run even on a supply voltage as low as 2 Volt. If you have peripherals that work at 5 Volt you could always use a step-up converter to step-up the power supply from 3 Volt to 5 Volt. Kind regards, Rob ________________________________ Van: [email protected] <[email protected]> namens vsurducan <[email protected]> Verzonden: woensdag 29 juni 2022 09:11 Aan: [email protected] <[email protected]> Onderwerp: Re: [jallib] sun power use You may continue to use it at 5V if the energy extracted from the PV is drawn via a MPPT ( maximum power point tracking) IC and your solar panel assures the current needed for your electronics. Many panels have 6V open at 0.3A or 0.5A short circuit current Actually any actual PICmicro will run on 3.3V ( including those rated for 5V) if the internal oscillator is set to maximum frequency intended only for 3.3V. Most of the low power PICs ( LF series) will run down to 2.2V ( some down to 1.8V) so you may connect the solar panel directly on your LDO without MPPT or PWM. best wishes On Wed, Jun 29, 2022 at 9:57 AM hans <[email protected]> wrote: Hello all, I don't want to reinvent the wheel. Until now I have always used 5 volts supply voltage, but because of a solar panel I would like to work on 3 volts. Which processors should I use and what should I pay attention to? Thank you in advance, greetings Hans -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/3220a563-f63f-435b-b0a6-c088cc777aaen%40googlegroups.com<https://groups.google.com/d/msgid/jallib/3220a563-f63f-435b-b0a6-c088cc777aaen%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/CAM%2Bj4quz-mvFLM7nuWmPg0YBcQCGNLDqw09bJMr%3DbKpmALa9TQ%40mail.gmail.com<https://groups.google.com/d/msgid/jallib/CAM%2Bj4quz-mvFLM7nuWmPg0YBcQCGNLDqw09bJMr%3DbKpmALa9TQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/b59b60f5-848e-4d33-b9d9-a6bc2b872dabn%40googlegroups.com<https://groups.google.com/d/msgid/jallib/b59b60f5-848e-4d33-b9d9-a6bc2b872dabn%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/GVXP195MB1637E6A59B7619F80BB4F423E6BB9%40GVXP195MB1637.EURP195.PROD.OUTLOOK.COM.
