@gregvp said in Fork of BigClive AA Battery Trickle Charger: I have a project on my list to make a NiMH capacity tester using as the load a boost regulator loaded with a range of resistors. But at my current rate of progress through the list, I'll be dead first. Luckily, if you want to do some testing before you die, you can get pretty decent load testers for cheap these days. Not sure how accurate they are in an absolute sense, or how accurate you would need them to be for your particular purposes, but for anything I do they seem "good enough" and provide repeatable capacity numbers. https://www.aliexpress.us/item/2255800047204598.html?spm=a2g0o.productlist.0.0.1e963f191wOpcX&algo_pvid=8930e84c-2b17-4afd-9458-68d1aabbc9bc&algo_exp_id=8930e84c-2b17-4afd-9458-68d1aabbc9bc-20&pdp_ext_f={"sku_id"%3A"10000000947167753"}&pdp_npi=2%40dis!USD!13.43!9.67!!!!!%402101d8b516678388477845208e191c!10000000947167753!sea&curPageLogUid=kEzSSWx2qqOU I agree with your comments regarding the likely use of niMH batteries. Not sure what load to pick, but I do need to pick some kind of reference load--maybe 1C?--so that I have some way of gauging whether or not the cells kept 24/7 in the forked BigClive trickle charger degrade noticeably more than cells which aren't. In the end I suspect Calendar aging will be the biggest effect, but I won't know for sure unless I run the experiment.