How many times can a NiMH battery be recharged? --- 1000 times

 https://www.batterystuff.com/kb/articles/battery-articles/proper-care-and-feeding-of-a-nimh-battery.html

can be recharged up to 1000 times in overnight slow charge mode, while 2100 to 2400 mAh rechargeable batteries can be recharged up to 600 to 800 times in overnight slow charge mode.