Not even bothering with the white wire anymore. Last fall I bought a wall wart trickle charger to keep my SLA topped up because even riding for days at a time wouldn't add much charge to it and now I know why. I'm just using the trickle charger to charge my nicads now which takes about 3 hours.
I just remembered, I have a dedicated nicad/nimh charger somewhere in the basement from back before I switched to lipos in my airplanes. That'd charge my packs unattended in about an hour.