Sure, I'm open to using a solar trickle charger -- or the same thing plugged-in. I don't move the bike. So, I am not worried about cords and the like. I just want a cost effective solution that does the job. I thought a wall-wart was the simplest and cheapest solution, but I have just enough...
I have a LifeFitness exercise bike. It uses a Hawker Energy Sealed Lead Rechargeable Battery that is three cells with a rating of 6 volts at 2.5 AmpHours for 1019 Watts.
The battery is recharged by usage of the bike. However, the bike is designed for commercial use and the battery discharges...