Jerry DuBois was making a good living operating his own company – one that makes seed counters for Pioneer and Monsanto. He didn’t really need to start another business. West Des Moines-based DuBois Engineering Co. sells its product in at least 10 countries and “we do pretty well,” its owner and founder said.

But give an inventor-type like DuBois a problem and he can’t stop himself from solving it.

DuBois’ problem? One night last year he was on a nice evening bicycle ride on the Great Western trail from Des Moines to Cumming and Martensdale, when his cycling companion’s bike broke down.

The companion got a ride home, but there wasn’t room for DuBois’ bike in the car, so he decided to ride back to Des Moines by himself.

No worries, he thought. He had not one, but two “little Walmart lights” on his bike.

“I was out at 11 o’clock at night. You can’t even see five feet in front of you on a pitch black trail even with the lights. It was slow going. You have to go about walking speed,” he said.

So DuBois designed a more powerful headlight setup with a rechargeable lithium battery. Then he saw how often bicyclists used their mobile phones on their rides – checking GPS, playing music, calling each other - and how much in demand phone charging outlets are on organized rides. So he invented a heavy-duty charger that fits into a bicycle water-bottle rack.

DuBois was marketing those products for the first time at the Iowa Bike Expo at Community Choice Credit Union Convention Center at Veterans Memorial Saturday through his new business, Johnson Charger.

"We got a pretty good response," he said.

Johnson Charger wants to position itself as selling high-quality accessories for serious recreational cyclists, which might also appeal to hikers, campers or other outdoor enthusiasts. The charger sells for $250 ($350 if you buy the model with the built-in MP3 player) and the bike headlights sell for $275.

He's planning to market the product this summer on the "Register’s Annual Great Bicycle Ride Across Iowa.”