battery for dell laptop

The battery in my Dell laptop is dead, finished,
defunct. I need to replace it and since Dell wants
about $165 for it, I decided to check out other
sources. I was given the website for a company
that is well rated.

They do indeed have a replacement for my battery and
for only $65, however the specifications on theirs
are slightly different and I wonder if that could
cause problems. Would anyone reading this happen to know anything
about this kind of thing in general?

For instance the voltage on my original is 14.8
while the one they offer as replacement is 14.4.
And my original says 3800 mAh (whatever that is),
while their replacement is 4000 mAh. Would these
these particular differences should cause a problem?

best, Aaron in N. Hollywood