Li-po battery connection

Hi, i somehow ended up with two lipo batteries, one is 7.4V 2000mAh and the other 3.7V 2000mAh. Is it safe to connect them together? If so in series or parallel? and what kind of voltage and current would i get in each combination? picture of the batts in the link. pls advise.. Thxs!

Definitely not in parallel!

You can connect the batteries in series and you will get 11.1V. The current draw will be determined by what you hook up to the batteries. The 2000mAh rating tells you how much energy they store (on a good day you can draw 2000mA for 1 hour, or 1000mA for 2 hours, etc. though this is a big simplification).

Definitely be careful in charging the batteries. You can't just put them in series and hook them up to an arbitrary charger.

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