Just re-charge it!
A few weeks ago, I took the opportunity to attend a car show at the Bob’s Big Boy in Burbank, California. While I was there, a guy with an electric car came in with his kids. I was sitting with a friend who has a classic truck at the show.
When the guy came around where I was, he was holding an extension cord looking for a plug to recharge his battery in his new electric car. I told him that if he parked his car next to mine, I could recharge his battery while he was there.
He pulled his car over to where mine was parked and plugged his extension cord into the invertor I installed under the hood. For the next 4 hours, my invertor was generating 110V AC, charging his battery. I did not even have the engine running, but the battery on my car never dropped below 13.1 V DC. The solar cell I have on the dash kept the battery fully charged. At about 7:30, he informed me that his battery was fully charged.
It’s always nice to help out a total stranger once in a while. I found out that he has 2 other Honda cars at home, so I WILL be seeing him again.