I've carried out a reasearch on batteries and have found some models fitting DR1000.
VARTA PLF 503759 -This is the newer version of "original" one, I believe (about 1000mAh):
VARTA LPP 503759 8HH -This is the newest version of the "original" (1400mAh):
Dianionics DLP 543759 - This one looks good as well (about 1300mAh):
Yoku Energy 573450 - The worst one (about 900mAh):
I'd like to buy LPP 503795 8HH or Diaconics DLP 543759 but I can't get any of them in my country. I would highly appreciate if someone could help me.