solar trickle charge?

I have adopted bank charging, and I'm in the process of figuring out how to carry chargers to work since I understand that SLA batteries need frequent charging for longer life. Out of curiosity ... has anyone tried a solar trickle charger to maintain the health of SLA batteries until you can get home to your bank chargers? Of course, you'd need sunny days and those aren't always available, but theoretically, if the sunlight were available, would it help to take care of a battery until charging later?