So I recently sold my n80 and when I sold it I sold it with the charger that originally came with the nokia 3100b from AT&T Wiress with the adapter needed to charge the N80.

So I have this N80 charger here now. can this charge a 3100b? the problem is that this charger has circular pins instead of the straight prongs and the connector is the smaller one for the n80.

Yesterday I bought a cheap chinese charger for my 3100b but honestly don't know how smart it is re: shutoff when battery full for instance. Do even the cheap ones do this today?

I know there's an adapter to adapt from big to small but is there an adapter for small to big? the output on this charge is 5v/890ma where as on the cheap one
it's 8.5v/400ma

The charger is the same - electric part. But the adapter must be changed. When is the opposite, Nokia sell the phones with CA-44 adapter. You want the opposite. If it exist, is possible.

Ive never seen the opposite but yeah, it must be avaialable or possible.