

Solar charge panel overheated smartwatch
Hey, hope you're well.
Not sure if this is the ideal place to post, but seems reasonable given that it relates to the charging of the battery.
I used this solar charge panel to charge my OnePlus Watch 2, and it's worked generally fine in the past, though on this occasion the watch became exceedingly hot, and I got a temperature warning which I've never seen before.
I charged using a USB A cable.
I've previously charged a power bank which also became rather toasty. I keep the devices out of the sun.
I don't experience this level of heat with traditional charging.
My question is, is it normal for solar charge panels to heat devices to this level? Are there workarounds?