Even though SEMA has received  most of the attention this week, there’s an arguably more important gathering going on right now at COP26 in Glasgow, Scotland. A small, recently-formed company called ZipCharge has debuted a portable EV charger at the United Nation’s annual climate change conference. And even though the device has some disadvantages, it it could help drivers with range anxiety.

This is similar to the portable battery our own Jason Torchinsky thought up years ago, and this one’s called the ZipCharge Go. The company claims it will provide 20 to 40 miles of range. That’s a big difference! Likewise, the charging time varies from 30 to 60 minutes. The range and time depends on the EV model being charged, the EV’s capacity and external temperature.

The Go itself charges from household plugs, meaning there’s no special equipment needed. It uses a Type 2 socket, which is standard in the EU, but differs from the J1772 plug used in the American market. So, you couldn’t just buy one and have it delivered to the U.S. when it goes on sale next year.

The ZipCharge Go’s sales model is also unclear. The BBC reports that the outright price is unknown, but a monthly subscription could cost £49, or around $66. That’s way too much, if you ask me! Also, subscriptions suck.

Speed? I am speed. Go up to 19mph for 5 hours over a max range of 13 miles, thanks to a 350W brushless motor, with all the safety features you could need.

In a way, it’s a modern companion to a spare tire — though full-size spares are sadly not common anymore. I know I’d want both a spare tire and spare battery next to my luggage if I were 0n a road trip in an EV.

ZipCharge even compares it to a suitcase, and it does look like generic rolling luggage, though it’s heavy at about 50 pounds. But the company doesn’t think the utility of the Go is limited to its use as a spare battery. It says the portable charger is good for top-ups while out and about, or for those who don’t have a charger at home. Like, say, folks who live in an apartment building.

I’m not sure I agree, because I probably wouldn’t leave it connected to my car unsupervised, and would be more hesitant to leave it next to my car if I was street-parked. Maybe it’s just me, but it sounds like someone could easily unplug it and roll it away. However, the Go will have cellular connectivity, per the BBC , meant for use with a smartphone app, so it might be easy to track.

Overall, the ZipCharge Go is a good idea. A 20-mile boost is small, but it could be helpful in an emergency. A 40-mile boost, on the other hand, is substantial and might convince someone towards electric who has been on the fence.