Smell when Charging

Starting last week, we noticed the smell of burning rubber, resister, or dust coming from under the passenger seat (where half the batteries are) during charging.
We of course have not charged our Ford Think since then.
I took the seat cover off but didn’t see any smoke, nor any evidence of anything burning or having been burned.
Anybody out there ever have a similar experience??
I plan on calling the company that installed the new Gel batteries a few months ago to come back and check it out.
But I wanted to know if anyone had anything I should take a closer look at before they are available to make the trip out.

Ken Hansen

Check all connections for bright and tight.

Start the charger and see if any of the connections get hot.

Temperature sensor located on negative terminal of battery #6 under the passenger seat, if it has the Delta Q charger. Could be an issue they do go bad.

We had OC Monster Carts come out. Turns out it was the original fuse box. Once we got the seats out we could see the smoke coming from there. They installed a bypass. All good now!