Issues with battery not made for new engine??

[Supersereal]

I swapped a B18C (GSR) engine into my 95 Civic coupe and I didn't upgrade the battery from the old engine (the D16). And now am having my lights dim and other such issues.

Do I need to get a bigger battery for the new engine? Or maybe my battery is just losing power?

Any help would be greatly appreciated!
Thanks in advance.

 

[eg6sir]

was it doing this before the swap? check the alternator, usually the suspect w/ dimming

 

[josh_crewdson@y]

X2. check your alternator since that's the only thing that has changed in the charging system.