My video shoots use a lot of AA & AAA batteries. I tried Li then NiMH rechargeables, to ensure I start shoots with fully charged batteries, and avoid mounds of half-spent batteries after a shoot (to figure out how to get the value out of).
But every single brand of rechargeable I've bought has been terrible. Even brand new, they hold WAY less mA-hr than alkaline. And the claimed low self-discharge rate of NiMH has turned out to be marketing-speak garbage. Most of mine lose 20-50% of their charge in a day or so. Some take a few months to get that bad. Others start off that bad right out of the retail packaging.
I've always bought big name brands with lots of reviews, and mostly >4/5 stars. But this has not helped at all.
My question: has anyone found tricks or brands for better results? Periodically fully discharging mine has not helped.
This AA & AAA rechargeable battery performance is in marked contrast to the device-specific OEM batteries (for cameras/camcorders/DARs/etc.) and most USB external batteries, which tend to perform well for at least 2-3 years. So, apparently the technology exists to make a battery that doesn't lose capacity and lose charge so quickly. But no one seems to be putting that better build tech into AAs & AAAs.
FWIW, my experience with AAAA rechargeables has been even worse, with about half leaking white powder from the cathode upon first charge (using an excellent/proven-good charger), and all getting returned. (I see Amazon has since stopped selling the ones I'd tried.)