Amazon.com : Synergy Digital Camera Battery, Compatible with Canon EOS 40D Digital Camera Battery Lithium-Ion (1500 mAh) - Replacement for Canon BP-511 Battery : Electronics
Duracell Camera Battery - Is it any good? - YouTube
Duracell DR9967 Li-ion Camera Replaces Battery for LP-E10: Amazon.co.uk: Electronics & Photo
Synergy Digital Camera Battery, Compatible with Canon EOS 40D Digital Camera Battery Lithium-Ion (1500 mAh) - Replacement for Canon BP-511 Battery : Electronics - Amazon.com
Amazon.com: BM Premium LP-E19 High Capacity Battery for Canon EOS R3, EOS 1D X Mark III, EOS 1D X Mark II, EOS 1DX, EOS 1Ds III, EOS 1D IV, EOS 1D III Cameras : Electronics
Amazon.com: BM Premium LP-E19 High Capacity Battery for Canon EOS R3, EOS 1D X Mark III, EOS 1D X Mark II, EOS 1DX, EOS 1Ds III, EOS 1D IV, EOS 1D III
Amazon.com: BM Premium LP-E19 High Capacity Battery for Canon EOS R3, EOS 1D X Mark III, EOS 1D X Mark II, EOS 1DX, EOS 1Ds III, EOS 1D IV, EOS 1D III Cameras : Electronics
Best Buy: Duracell Battery for Canon 8mm Camcorders DR12AA
Amazon.com: BM Premium LP-E19 High Capacity Battery for Canon EOS R3, EOS 1D X Mark III, EOS 1D X Mark II, EOS 1DX, EOS 1Ds III, EOS 1D IV, EOS 1D III Cameras : Electronics
Seems, I just got a counterfeit LP-E6NH battery (see comments for more details) : r/canon
BEST BATTERIES FOR YOUR SPEEDLIGHTS: A SHOWDOWN - Improve Photography
Amazon.com : Synergy Digital Camera Battery, Compatible with Canon EOS 40D Digital Camera Battery Lithium-Ion (1500 mAh) - Replacement for Canon BP-511 Battery : Electronics