You'd only need one, and then you'd have essentially the lightbulb solution I mentioned. It would limit current to a safe level but it would not allow your charger to properly charge the battery without over-charging.Perhaps, a resistor inline with each terminal clip?
Yes, in the end, you're right. I'm of the mind to just get a 6V charger. Perhaps, a trickle unit for long term usage.You'd only need one, and then you'd have essentially the lightbulb solution I mentioned. It would limit current to a safe level but it would not allow your charger to properly charge the battery without over-charging.
A dedicated charger is your best (easiest, fastest, cheapest) bet, IMHO.