Dead Car Battery Starter for EVs?

by Wen
(Vancouver, BC)

I got an "emergency battery charger" kit for my regular car - the kind you plug into the cigarette lighter when you're miles from nowhere with a dead car battery. It's light, you just carry it around in the glovebox.

My question is, could I use something like this in an EV to recharge my batteries? I don't want to get stranded.

Hi, Wen -

Yes, I've seen these too! You can get something like this
black and decker 12v battery booster pretty cheap (around 50 bucks, maybe less), it's lightweight, and if your EV runs out of charge on a cold winter's night, you can plug this in to your cigarette lighter and be on your way, yes?

Actually, no.

This device is a battery booster, which means that over a period of 10-20 minutes, it will transfer enough juice from itself to your starter battery to get you on the road again, if your car is a gas-guzzler. It only replaces the surface charge, it doesn't actually do much charging.

Your electric car, on the other hand, drinks deeply from the batteries, and requires a real investment of electrons to get up and moving again. If those batteries are drained, no amount of surface charge is going to get you up and moving again.

(It seemed like such a good idea, didn't it?)

To read more about the nature of "deep cycle" batteries vs. the "starter" type, read my deep cycle battery article.

Regards,
Lynne