+1 on Ratch's comment on standardizing to AA (NiMH)... after 2004 I switched to Eneloop AAs for my area, task and head lights, weather alert and AM/FM radios... while I have a 7W Goal Zero charger, I used a power strip to connect multiple NiteCore chargers when I ran the generators keeping the computer, TV, and refrigerator up for Irma, the solar is relegated to a back up position ... if you live in storm country, invest in a generator