@Override @SideOnly(Side.CLIENT) public void addCheckedInformation( ItemStack itemStack, EntityPlayer player, List<String> toolTip, boolean advancedTooltips) { final NBTTagCompound tag = itemStack.getTagCompound(); double internalCurrentPower = 0; double internalMaxPower = this.getMaxEnergyCapacity(); if (tag != null) { internalCurrentPower = tag.getDouble("internalCurrentPower"); } final double percent = internalCurrentPower / internalMaxPower; toolTip.add( GuiText.StoredEnergy.getLocal() + ':' + MessageFormat.format(" {0,number,#} ", internalCurrentPower) + Platform.gui_localize(PowerUnits.AE.unlocalizedName) + " - " + MessageFormat.format(" {0,number,#.##%} ", percent)); }