Phone heats up while charging and won't turn on

Good day people! Our home just got struck by the typhoon Odette, and for 6 days, I was not able to charge my phone. The phone in question is 6 years old, and in fact it still works good, although my only problem was the fast battery drainage which would only make my phone last for 6 hours without charge. I cut my usb cable charger and plugged the positive and negative wires into a battery I found, and I accidentally sticked them to the wrong portion, which results in the charger wires smoking. After that, my phone after charging it with the correct wires placed, the led indicator stays on for a while and heats up when charging. Should I get this to a battery repair shop or should I just charge it more (our electricity just came back now). Thank you in advance for the answers.