Stick with AGM or go lithium for backup power in the South?

[King_Troad]

Down here in Mississippi, it’s still hitting the high 80s some days, and I’m starting to wonder if lithium really holds up long-term in this kind of heat. I’ve been running AGM batteries for years in my backup system like no fancy maintenance, just steady performance... but everyone keeps pushing lithium like it’s bulletproof.
For folks running lithium setups in hot, humid areas, how’s it holding up after a year or two? Are you seeing capacity loss, or is it mostly marketing that they’re “fine” in any climate?

 

[Anlucia_Light]

that “works anywhere” pitch is a bit of marketing spin. Lithium’s great on efficiency, but constant high temps accelerate degradation. AGMs can take the heat better, they just can’t go as deep or last as long if cycled often. Depends what you value more.

 

[blu3 li4m]

Are you seeing capacity loss, or is it mostly marketing that they’re “fine” in any climate?

well, capacity loss in hot, high-SoC environments is a real chemical fact. After two years in a consistently hot (like 104°F) environment, lithium batteries can lose significantly more capacity than they would at 77°F.
The specific amount depends on the quality and the battery's operating temperature management.

 

[Alan]

that Southern humidity doesn’t do electronics or batteries any favors. A few users have mentioned lithium holding up fine if it’s shaded and properly ventilated, but outdoor setups take a beating. Do you plan to keep your system in the same space as your AGMs, or are you considering moving to a climate-controlled area if you switch?