Solar panel charging circuit

in power supply by DP | 2 comments


Solar panel charging circuit:

A special circuit is needed when charging a battery from a Solar Panel. When the solar panel is not providing any power the battery might start draining current into the panel. One common solution is to have a diode in series with the charging circuit to keep the current from going back to the solar panel. The problem with using a diode is the voltage drop across the diode reduces the available voltage for charging.

This circuit is great because the LTC4357 prevents the current back feeding into the panel without having the voltage drop limitation of the diode circuit

Via Electronics Lab.

This entry was posted in power supply and tagged , , .


  1. There are some clever and low-part-count ways of doing this without any specialized controller. The LTC4357 looks really cool and is almost certainly ideal for the use, but you’re paying a lot for the operating voltage range compared to what you can get with a couple fets. The other thing is, you lose a lot by simple switching of a solar cell into a load like this. a switching controller, perhaps even maximum power point tracking, isn’t much more expensive for a huge performance increase.

    Maybe I’ll reply in blog-post format when I get a chance, there’s a lot to discuss here!

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