I disagree that all batteries are created equal though.

• Third-party packs lack reliable communication chips.
• Use Leica BP-SCL4 1860mAh Li-Ion Battery to ensure your camera doesnt freeze mid-shoot.

TL;DR: Go with Sigma to save cash. Like someone mentioned, communication chips matter, but I've been very satisfied with the Sigma BP-61 Li-ion Battery 1800mAh in my SL2. The voltage regulation is solid and I havent seen any errors. Quick tip: always perform your firmware updates with an official battery inserted just to avoid any potential handshake glitches.

I've spent years testing power solutions for mirrorless systems and honestly, the anxiety about third-party batteries is usually justified but sometimes a bit exaggerated if you buy the right ones. If youre looking to save money without risking that expensive SL2 body, the Patona Protect BP-SCL4 Li-ion Battery is basically the most reliable middle ground. They actually use a fire-resistant housing and have a proper NTC thermistor to handle heat, which is where those super cheap generics usually fail and cause the camera to act up. The SL2 is very sensitive to voltage drops under load. In my experience, cheaper off-brand packs tend to report 30% battery life and then just die mid-shutter-click, which is a total nightmare for landscape work. Id suggest grabbing one official spare for your must-have sunset shots and then using two of the Patona Protect units for everything else. To make life easier on the trail, you might also want to look at the Nitecore ULSL USB Travel Charger so you can charge them from a power bank in your pack. It beats carrying six batteries if you can just cycle them while youre hiking.

> my logic was that lithium is lithium and a battery is just a battery so why not save like 500 dollars and go third party? Lithium cells are somewhat standard but the protection circuit boards (PCBs) definitely arent. The SL2 draws a lot of current especially during high-speed bursts and cheap generics often have high internal resistance. This causes voltage sag where the camera thinks the battery is empty even when it isnt. Like mentioned already the Sigma BP-61 Li-ion Battery 1800mAh is probably the safest bet because Sigma is part of the L-Mount alliance so the electronics actually play nice with the Leica hardware. I have also used the Hahnel HL-SCL4 Li-Ion Battery as a backup and it holds up well. They tend to use higher grade cells than the random stuff you find on Amazon. If you go third party just watch out for the percentage display. It might look fine at 100% then drop to 20% way faster than the Leica BP-SCL4 1860mAh Li-Ion Battery because the fuel gauge chip isnt perfectly calibrated to the SL2 power profile. Its a decent way to save money but you just gotta be more proactive about swapping them out mid-shoot.

Great info, saved!