The typical (USB type) Lithium Ion battery charger outputs 5.0 volts. The batteries themselves are likely 3.6-3.7v, so in theory you might be able to charge with 3 alkaline batteries, (4.5v), though this may be a bit skimpy achieve a maximum charge.
HOWEVER lithium batteries are prone to overheating during charging, and you may run a high risk if charging without some kind of resistor to slow the process. I'm sure you can get better and more specific information if you search the net asking about charging lithium batteries.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.