I went for a quiet local ride today and just a short way out of town I came across a broken down driver.
About 8km from town. Seems he had a flat battery and no phone.
Around a month ago, I bought a digital jump starter when my alternator was a bit dodgy, and got it from the pannier. He had never seen one of these before.
The guy looked at it very dubiously, and said he thought it was totally inadequate for the job because it was so small. (About the size of two cig packets)
HIS CAR FIRED UP IMMEDIATELY, AND i FOLLOWED HIM BACK TO TOWN, WHERE HE STOPPED AT THE AUTO SHOP TO BUY ONE OF THESE UNITS FOR HIMSELF.