I've set up a solar system for my off-grid shop, featuring a Victron 150/35 MPPT charger paired with a LiTime 12.8/230Ah smart battery. My system has two 405w solar panels connected in series and I run about 400w of LED lights. While the setup charges my battery efficiently, I've noticed that during the day when I'm using the lights, the charger stays in 'float' mode and doesn't supply power directly to them, allowing the battery to discharge instead. Interestingly, when I adjusted the float voltage from 13.6 to 15v, the output increased to 420w, which powered the lights and stopped the battery drain. It seems like the battery's BMS keeps the voltage steady at around 13.5v until it's close to 50% capacity, preventing the Victron from ramping up its output when needed. I'd love to know if there's a way for my panels to directly power the lights without drawing from the battery until absolutely necessary. Is this feasible with my current setup?
2 Answers
Honestly, it sounds like your system is operating as it should by design. If it tries to drop into compensating mode too early, it would risk overcharging. You'll want to keep an eye on how much load is running versus what the panels can offer during the day. Maybe try reaching out to Victron support; they might have additional hardware or advice on enhancing your setup.
It sounds like your float voltage is set right at about 13.4-13.6, which is good. But here’s the deal: once your battery hits that float state, the charge controller switches to maintenance mode and will only kick back into bulk charging when the battery is low enough. This means it can't power the lights directly when things are at float. You might want to consider adjusting your system to allow it to output more power at that point, but it’s designed to maintain the battery primarily.
Exactly! Your system is really smart in how it manages power. Once you're at float voltage, the charger is more focused on keeping the battery topped off rather than providing power directly to your devices. It’s definitely a balance between charging and direct supply.