Hey everyone, I'm relatively new to the solar scene and recently got a mini solar system (50W panel, PWM controller, and a 9Ah battery) just to charge my mobile devices. It's been working fine, but now I'm thinking about upgrading to a bigger setup. I've got my eye on a LONGI Hi-MO X6 LR7-54HTH (455W) panel and I'm curious about what I need to successfully manage this more powerful system. I've done a bit of research and believe I'd need a battery with at least 200Ah capacity and possibly an MPPT controller like the Qoltec MPPT 30A. Or is a 20A controller sufficient? I've been advised that a bigger battery is essential to handle the influx of power from a larger panel, and I understand that the charge controller regulates this, but it's still causing some confusion for me. Also, should I opt for a LiFePo4 battery or an AGM one? I've read that 24V systems are typically more efficient compared to 12V systems, but LiFePo4 batteries are significantly pricier. I'm leaning towards 12V AGM batteries for budget reasons. Finally, will this system be able to run a single 50W load continuously while also allowing me to use a few other devices through an inverter during the day? Thanks for your help!
1 Answer
You've got a lot of great questions, and I can see you've done some homework! First off, the advice you received about needing a larger battery is generally correct, especially to prevent overloading with that big panel. However, with a decent MPPT controller, you can indeed manage that situation safely. I recommend ditching the PWM controller entirely—those can turn into a real headache when scaling up, especially if they fail and connect directly to the battery. An MPPT controller from a reputable brand like Victron would provide better reliability and features like current limiting, which is critical when working with larger panels.
For battery choice, LiFePo4 is indeed a better option long-term, but if you're just getting started and want to play around, AGM could be a good way to go. As for voltage, 24V systems generally give you better efficiency, so definitely consider that direction if you want some long-term benefits. If you're looking into causing less hassle down the line, investing in a Venctron 100/20 MPPT would be a smart move. It'll give you the flexibility to learn as you go!
Thanks for all the insights! I'm sold on the Victron controller now, and I really appreciate the advice on battery types. Do you think leaning towards AGM for now is wise, especially with still having the potential to upgrade later?