I'm trying to optimize my solar setup and was wondering about the limits on power input to the battery bank. I currently have two Victron MPPT controllers with a max solar input of 1200W and 800W respectively, plus a third one running 400W from a separate array. These are all bifacial panels on a white roof, so I might be getting a bit more output in full sun. I'm thinking about adding another 600W to the 800W array to fully utilize the 100/50 controller. Additionally, I want to know if it's feasible to add another 1200W array with another 100/50 controller, but I'm uncertain about any potential limitations on the battery side. My battery bank consists of 8x100Ah batteries configured in series/parallel at 24V, and I'm also using a Victron Smart Shunt and balancer.
3 Answers
For your LiFePo4 batteries, remember that the maximum charge rate is basically 1C—meaning you can push about 9600W into your setup. However, for better battery life, charging at around 0.5C is recommended. Since you have quite a bit of wattage available, make sure you’re monitoring your charge rates to avoid overdoing it!
LFP batteries can handle higher charge rates compared to lead-acid ones, so you should be good to push more watts if needed. Just keep an eye on your individual battery charge rates; the more battery cells you have in parallel, the more you can manage without issues. If you're considering big expansions, maybe look into a management system like a Cerbo GX to keep charge limits in check.
With multiple solar arrays and controllers, you might want to orient some panels east or west to even out your charging throughout the day. This way, you won’t be trying to push all that power into your batteries at midday. I've got one charge controller with my panels in multiple directions and it helps balance out the production.
Totally agree! I've utilized a similar setup and it works wonders for my energy production throughout the day.