[ossiblue]

Have you washed the battery top causing the white powder to cover the top and move down to the sides? If not, it looks to me like the battery case is leaking around the top seam, allowing venting of gas when the battery is being charged. The white deposits, which are likely to be lead sulfate, look to be concentrated around parts of that seam.

If you did wash the top, the white deposits look to have come from the negative terminal (which looks a bit corroded), and if that's the case, it is generally due to undercharging rather than an over charge. Vehicles that are not used regularly and are not driven enough to fully charge the battery often have the build up on the negative post. Same with vehicles that have lots of electronics that draw down the battery when there's not enough drive time to fully charge the battery.