Hola Fabricio,
I would not expect too much from any „recovery“ function in a battery charger. It only works with NiMH/NiCd batteries and basically it is nothing else but a simple charge-discharge-charge program. A $ 20 budget is quite a challenge but if you are willing to spend a bit more than this I can recommend buying the Vapcell S4 Plus charger.
HKJ tested it and came to a quite positive conclusion.
https://budgetlightforum.com/t/-/59947
The updated version from 2020 has got some improvements. You can buy the charger from Vapcell on AliExpress or from Sofirn‘s webshop.
https://vapcell.aliexpress.com/store/group/VapCell-batteries/1084158_513344502.html