Hi Jake,
I think your equation is incorrect. For parallel (trivial) and series RC circuits driven by an arbitrary v[t] I get the solutions below. (Sorry about Out[4] -- this new code system seems awkward at best.)
In[1]:= parallelEq = i[t] == c v'[t] + v[t]/r
Out[1]= i[t] == v[t]/r + c Derivative[1][v][t]
In[2]:= (* trivial *)
DSolve[parallelEq, i[t], t]
Out[2]= {{i[t] -> (v[t] + c r Derivative[1][v][t])/r}}
In[3]:= seriesEq = v'[t] == r i'[t] + i[t]/c
Out[3]= Derivative[1][v][t] == i[t]/c + r Derivative[1][i][t]
In[4]:= DSolve[seriesEq, i[t], t]
Out[4]= {{i[t] -> E^(-(t/(c r))) C[1] + E^(-(t/(c r))) \!\(
\*SubsuperscriptBox[\(\[Integral]\), \(1\), \(t\)]\(\*
FractionBox[
RowBox[{
SuperscriptBox["E",
FractionBox[
RowBox[{"K", "[", "1", "]"}],
RowBox[{"c", " ", "r"}]]], " ",
RowBox[{
SuperscriptBox["v", "\[Prime]",
MultilineFunction->None], "[",
RowBox[{"K", "[", "1", "]"}], "]"}]}], "r"] \[DifferentialD]K[1]\)\)}}