Need to charge a 7.4v 2000mAh Li-Polymer Battery

Seve OB

As the title says I need to charge a 7.4v 2000mAh Li-Polymer Battery. I actually have 2 batteries for the same product, but the second one has no "Li". The second one is not the battery that came with the product.

It is a handwarmer, but the problem is when I was given it, I got no charger. It came from the good old U S of A. I think I can buy a charger for it online, but it is about €50 by hte time they have added up all the charges and then I'll probably be hit with a customs bill when it gets here!

Anyway, I've gone to Maplins where figured I would probably walk in and pick a charger up handy enough but they had nothing.

Now I have a charger that fits, but that kind of reminds me of when one of the kids got electricuted in the snapper and Jimmy asks them why they put their fingers in the socket to be answered "cause it fit"

Anyway, the charger is input 100-240v 50-60hz, and output 5v
I'm guessing the output is really all that matters. is it safe to charge a 7.4 v battery with a 5v charger?

by the way, there are no lights on either to let me know if charging is taking place or completed

ps i hope this is the right place to pose such questions, if not a mod can move it please

Seve OB

ok, i think i found a better place to post but cant seem to delet this thread