Eric_Jensen
New Member
- Joined
- Jul 10, 2022
- Messages
- 4
I'm planning to build a modest solar generator in order to have a bit of battery backup during a power outage. I have no plans to power the whole house for an extended time - just enough to keep the fridge on for a while, and power a few small lights, etc.
I'm planning on modeling it on this milk-crate build from Will Prowse (probably with a larger battery), which is a slightly modified version of the one in this video. I actually prefer the design in the video (with the AC power going into the MPPT rather than directly into the battery as in the first link), so that the MPPT can manage the battery charging cycle. (As I understand it from the comments on the video, the modification was to avoid problems with having the AC power and solar connected at the same time, which I wouldn't do - though I might also add some in-line diodes as suggested in the video comments.)
My questions involve trying to understand better how the MPPT controller handles different current loads, especially for non-solar input sources:
Thanks for helping me understand all of this better! I appreciate people taking the time to read and answer questions in this community.
I'm planning on modeling it on this milk-crate build from Will Prowse (probably with a larger battery), which is a slightly modified version of the one in this video. I actually prefer the design in the video (with the AC power going into the MPPT rather than directly into the battery as in the first link), so that the MPPT can manage the battery charging cycle. (As I understand it from the comments on the video, the modification was to avoid problems with having the AC power and solar connected at the same time, which I wouldn't do - though I might also add some in-line diodes as suggested in the video comments.)
My questions involve trying to understand better how the MPPT controller handles different current loads, especially for non-solar input sources:
- If I have a controller that is rated at, say, 15 A, does the controller manage that limit itself (only drawing 15 A or less), or is it on the user to design a system that will never provide more current than that?
- Does the answer to #1 change for controllers that allow programming of the max battery charge current, like the Victron SmartSolar? For example, if the max charge current is set to 10 A on, say, a 15 A controller, does that mean that it would not draw more than ~10 A (with possible differences based on different input vs. charging voltages, e.g. if charging at 13 V, 10 A, I understand that it would need to draw 130 W, resulting in input current of 130 W / 12 V = 10.8 A if connected to a 12 V source).
Thanks for helping me understand all of this better! I appreciate people taking the time to read and answer questions in this community.