Thanks for this, great info. After researching the batteries that were in my trimmer, I found out they were 750mAh. I purchased a 4 pack of 1000mAh batteries on Amazon for $10. They were called "1.2V Ni-MH AAA 1000mAh Rechargeable Battery w/Tabs." The tabs were a little longer than the original batteries and were covered in insulation. The insulation was easily removed and I just bent the tabs back over themselves so they wouldn't short anything out.