Q) Is it okay to use a phone charger to charge the speaker?
A) It is best to use a 5v or 5v:1a charger. Anything with a higher charge will blow the speaker battery (i would apply this to most bluetooth speakers). A phone charger is usually 5v:2a. The easiest thing to do is charge through the USB on your computer if you can't find a 5v or 5v:1a charger right away.