# How to charge and use a battery powered with Solar Cell Panel **URL:** \ **Category:** General Guidance\ **Created:** [October 24, 2021, 7:49pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100 "2021-10-24T19:49:25Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 7:49pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/1 "2021-10-24T19:49:25Z")
Hi! Im building a MPPT Solar Charger for a LiPo battery (2 Cells, 7.4V, 910 mAh). My design is using a Synchronous Buck Converter, that transform the 20 Voc and 0.33 A Isc from the Solar Cell Panel to charge the battery. While I didnt test the design in real situation, the simulation in PSpice is giving me some troubles when I insert a load that has to be powered from the battery. Arduino will be also powered from the battery, because the Solar Panel will be used just for charging the battery. Can anyone help me to understand how to power the load while the battery is charing? PS: If you need more information just ask. πŸ™‚ This is the schematic: ![Schematic](https://europe1.discourse-cdn.com/arduino/original/4X/4/2/0/4201e230bec2390107c65b4f7ae7f78da4c73d67.png) ---
**Author:** ![gilshultz](https://avatars.discourse-cdn.com/v4/letter/g/67e7ee/32.png) [@gilshultz](https://forum.arduino.cc/u/gilshultz)\ **Post date:** [October 24, 2021, 8:33pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/2 "2021-10-24T20:33:56Z")
Since I cannot find the schematic, maybe it did not post. I will take a SWAG and say connect the load to the battery. You need to be aware in your design of the charger that not all power is going into the battery. ---
**Author:** ![anon94801460](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon94801460](https://forum.arduino.cc/u/anon94801460)\ **Post date:** [October 24, 2021, 8:40pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/3 "2021-10-24T20:40:43Z")
Buck convertors don't work well with a solar panel, because solar panels are primarily current sources, with the current proportional to the illumination. The combination tends to oscillate or fail completely. By far the simplest approach is to just have the solar panel directly charge the battery, with cutoffs or current limiting to control the charge as required by the battery chemistry. Then you draw current from the battery. ---
**Author:** ![hammy](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/hammy/32/238813_2.png) [@hammy](https://forum.arduino.cc/u/hammy)\ **Post date:** [October 24, 2021, 9:09pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/4 "2021-10-24T21:09:50Z")
You need to look carefully how lipo’s are charged - there are some power management chips about for this purpose that will allow charging and supplying a load - but not easy to use . Using a lead acid battery would make life easier ---
**Author:** ![Idahowalker](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/idahowalker/32/238858_2.png) [@Idahowalker](https://forum.arduino.cc/u/Idahowalker)\ **Post date:** [October 24, 2021, 9:16pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/5 "2021-10-24T21:16:28Z")
> [@captain\_europe](#): > > Im building a MPPT Solar Charger for a LiPo battery (2 Cells, 7.4V, 910 mAh). Post your schematic for a MPPT solar charge controller for LiPo's. Your solar panels are producing 20V? What is the power rating of your solar panel as well as its real voltage rating loaded and unloaded? ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:21pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/6 "2021-10-24T21:21:59Z")
Updated with schematic ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:22pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/7 "2021-10-24T21:22:38Z")
Its rated 10W, but in real use is like 6.5W ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:24pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/8 "2021-10-24T21:24:16Z")
The project it is planned for a Cubesat (at least the prototip), so that type of batteries arent allowed to be used. ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:26pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/9 "2021-10-24T21:26:33Z")
Could you take a look at my recently upload schematic, please? πŸ™‚ ---
**Author:** ![Idahowalker](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/idahowalker/32/238858_2.png) [@Idahowalker](https://forum.arduino.cc/u/Idahowalker)\ **Post date:** [October 24, 2021, 9:41pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/10 "2021-10-24T21:41:35Z")
Will you be winding the coil or will you purchase one for the MPTT Charge controller. You state > [@captain\_europe](#): > > Cubesat A LifePo4 will work down to -40C uninsulated. ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:47pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/11 "2021-10-24T21:47:25Z")
I bought one of 500 uH ---
**Author:** ![anon94801460](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon94801460](https://forum.arduino.cc/u/anon94801460)\ **Post date:** [October 24, 2021, 9:49pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/12 "2021-10-24T21:49:40Z")
The schematic is incomplete. Please post the details of the PSpice models you are using for the sources labeled Solar, PWM\_H and PWM\_L. ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:54pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/13 "2021-10-24T21:54:39Z")
Yeah, sure! ![Schematic_2](https://europe1.discourse-cdn.com/arduino/original/4X/e/c/4/ec4f3c3e45001ae27c58851d0355ec62eb95d385.png) Updated ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:56pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/14 "2021-10-24T21:56:16Z")
Which topology do you recommend me for a Cubesat? The requirement is that the battery has to supply always the power for the loads, and the solar panel has to charge the battery when the Cubesat is on the sun side. ---
**Author:** ![anon94801460](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon94801460](https://forum.arduino.cc/u/anon94801460)\ **Post date:** [October 24, 2021, 9:56pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/15 "2021-10-24T21:56:35Z")
You are using a voltage source for Solar. That won't work, because a real solar panel is mostly a current source. ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 9:58pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/16 "2021-10-24T21:58:08Z")
Mmm...So, I should use a current source instead a Vdc + Resistance instead? I used a Thevenin equivalent. ---
**Author:** ![anon94801460](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon94801460](https://forum.arduino.cc/u/anon94801460)\ **Post date:** [October 24, 2021, 9:59pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/17 "2021-10-24T21:59:19Z")
You could look up what other people do, and avoid flailing around. This is one guide to modeling solar cells using SPICE: [https://nanohub.org/resources/12259/download/Users\_Guide.pdf](https://nanohub.org/resources/12259/download/Users_Guide.pdf) ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 10:05pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/18 "2021-10-24T22:05:01Z")
Yeah, but that isnt the problem of my simulations I guess...Because with the Thevenin equivalent Im building a current source too. ---
**Author:** ![anon94801460](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon94801460](https://forum.arduino.cc/u/anon94801460)\ **Post date:** [October 24, 2021, 10:13pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/19 "2021-10-24T22:13:17Z")
Good luck with your project! ---
**Author:** ![captain\_europe](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@captain\_europe](https://forum.arduino.cc/u/captain_europe)\ **Post date:** [October 24, 2021, 10:26pm UTC](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100/20 "2021-10-24T22:26:10Z")
I wrote here asking for help, not for luck πŸ˜… [Next page](https://forum.arduino.cc/t/how-to-charge-and-use-a-battery-powered-with-solar-cell-panel/918100.md?page=2)