Yes, the Nimh that came with. Has worked well so far, no complaints whatsoever. I used the scanner all day everyday and charged all night on this recent cruise, getting longer battery life than my SDS100. I think I like the audio on the TRX-1 better than SDS100, somewhat deeper and richer sounding to me. They (TSA) did not even look into my carry on backpack with several radios in it - my TRX-1, Yaesu FT2DR, a pair of Uniden SX-327s, my Canon digital SLR camera and iPad, and the worthless little H777 HT my bro-in-law purchased for onboard coms. I was a bit surprised, but I have Delta Sky Miles and TSA Pre-check, so that always helps I guess. They wave me on thru and just told me to take my hat off.