Haven't found the size mismatch - yet, but haven't you made a copy-paste mistake here :
Accu 10 {
type = "accumulator",
name = "accumulator-10 ",
icon = "__HTO__/graphics/accumulators/icons/accumulator-10.png",
flags = {"placeable-neutral", "player-creation"},
minable = {hardness = 0.2, mining_time = 0.5, result = "accumulator-10"},
max_health = 350,
corpse = "medium-remnants",
collision_box = {{-0.9, -0.9}, {0.9, 0.9}},
selection_box = {{-1, -1}, {1, 1}},
fast_replaceable_group = "accumulator",
energy_source =
{
type = "electric",
buffer_capacity = "50MJ",
usage_priority = "terciary",
input_flow_limit = "3000kW",
output_flow_limit = "3000kW"
},
picture =
{
filename = "__HTO__/graphics/accumulators/accumulator-9.png ",
priority = "extra-high",
width = 124,
height = 103,
shift = {0.7, -0.2}
},
charge_animation =
{
filename = "__HTO__/graphics/accumulators/accumulator-9-charge.png ",
width = 138,
height = 135,
line_length = 8,
frame_count = 24,
shift = {0.482, -0.638},
animation_speed = 0.5
},
charge_cooldown = 30,
charge_light = {intensity = 0.3, size = 7},
discharge_animation =
{
filename = "__HTO__/graphics/accumulators/accumulator-9-discharge.png ",
width = 147,
height = 128,
line_length = 8,
frame_count = 24,
shift = {0.395, -0.525},
animation_speed = 0.5
},
discharge_cooldown = 60,
discharge_light = {intensity = 0.7, size = 7},
working_sound =
{
sound =
{
filename = "__base__/sound/accumulator-working.ogg",
volume = 1
},
idle_sound = {
filename = "__base__/sound/accumulator-idle.ogg",
volume = 0.4
},
max_sounds_per_type = 5
},
},