Results are in.
My "40v" batteries measured 40.64v fresh off the charger.
The batteries are labeled as 5Ah 180Wh. My discharger maxes out at 150 watts, so I couldn't set the discharge to 5Ah (1C). Instead I set the discharge to constant 150 watts. I set discharge termination at 30v.
The first battery took 1:05 to deplete 4507mA and 164Wh.
The second battery took 1:04 to deplete 4402 mA and 159 Wh.
I've used the batteries for 1.5 years to mow the lawn, blower, and chainsaw during the ice storm. I consider the use to be normal.
An hour discharge is pretty unusual, as the mower would deplete the battery in probably an hour or less, the chainsaw in probably 40 minutes, and the blower perhaps 25. In other words, I roughly approximated a 1C discharge test and obtained 91% of the rated capacity.
Perhaps they have degraded 9% already. New batteries degrade rapidly at first.
I'll have to buy some knock off Aliexpress batteries and see how they compare. My dad bought a 4 battery 120v Ryobi inverter for reasons unknown. He's already got 2 tri-fuel gensets, a PTO Harbor Freight 240v genset, and now the Ryobi 120v inverter. I'd classify him as a moderate prepper without a plan.
