Program: 145983
Project: 145983
Buggy source:
@Override public void updateEntity(){
  super.updateEntity();
  if (worldObj.isRemote)   return;
  int energyReq=ENERGY_MAX - currentEnergy;
  if (currentEnergy < 0)   currentEnergy=0;
  if (currentEnergy < ENERGY_MAX && !(!this.isRSActivated && this.getCurrentBehavior() == EnumBehavior.RECEIVEONLY)) {
    ItemStack sl=slots[2];
    if (sl != null && sl.getItem() == Items.redstone) {
      if (energyReq > 500) {
        this.decrStackSize(2,1);
      }
      currentEnergy+=500;
    }
 else     if (sl != null && sl.getItem() instanceof ISpecialElectricItem) {
      ISpecialElectricItem item=(ISpecialElectricItem)sl.getItem();
      if (item.canProvideEnergy(sl)) {
        int cn=energyReq < 128 ? energyReq : 128;
        cn=item.getManager(sl).discharge(sl,cn,2,false,false);
        currentEnergy+=cn;
      }
    }
  }
  if (this.isUsing) {
    for (    EntityPlayer charger : chargers) {
      currentEnergy-=5;
      this.doHealing(charger);
      if (worldObj.getWorldTime() % 15 == 0) {
        worldObj.playSoundAtEntity(charger,"String_Node_Str",0.3F,1.0F);
      }
      if (currentEnergy <= 0) {
        this.chargers.clear();
        this.isUsing=false;
        worldObj.playSoundAtEntity(charger,"String_Node_Str",0.5F,1.0F);
      }
    }
  }
  if (slots[0] != null && slots[0].getItem() == Items.potionitem) {
    int dmg=slots[0].getItemDamage();
    List<PotionEffect> list=Items.potionitem.getEffects(dmg);
    PotionEffect effect=list.get(0);
    if (mainEff < HEALTH_MAX) {
      if (effect.getPotionID() == Potion.heal.getId()) {
        if (currentEnergy > 5) {
          currentEnergy-=5;
          prgAddMain++;
        }
 else         currentEnergy=0;
        if (prgAddMain >= PROGRESS_TIME) {
          this.setInventorySlotContents(0,null);
          mainEff+=(effect.getAmplifier() == 0 ? 12 : 18);
          prgAddMain=0;
        }
      }
 else       if (effect.getPotionID() == Potion.regeneration.getId()) {
        if (currentEnergy > 5) {
          currentEnergy-=5;
          prgAddMain++;
        }
 else         currentEnergy=0;
        if (prgAddMain >= PROGRESS_TIME) {
          this.setInventorySlotContents(0,null);
          if (dmg == 8193)           mainEff+=36;
 else           if (dmg == 8257)           mainEff+=96;
 else           if (dmg == 8225)           mainEff+=38;
          prgAddMain=0;
        }
      }
 else       prgAddMain=0;
    }
    if (mainEff > TileHealthCharger.HEALTH_MAX)     mainEff=HEALTH_MAX;
  }
 else   prgAddMain=0;
  if (slots[1] != null && slots[1].getItem() == Items.potionitem) {
    int dmg=slots[1].getItemDamage();
    List<PotionEffect> list=Items.potionitem.getEffects(dmg);
    PotionEffect effect=list.get(0);
    if (TileHealthCharger.availableIds.contains(effect.getPotionID()) && sideEff < EFFECT_MAX) {
      if (this.sideEffectId == 0 || effect.getPotionID() == sideEffectId || this.sideEff == 0) {
        this.sideEffectId=effect.getPotionID();
        if (currentEnergy > 5) {
          currentEnergy-=5;
          prgAddSide++;
        }
        if (prgAddSide >= PROGRESS_TIME) {
          this.setInventorySlotContents(1,null);
          sideEff+=effect.getDuration();
          prgAddSide=0;
        }
      }
 else       prgAddSide=0;
    }
    if (sideEff > TileHealthCharger.EFFECT_MAX)     sideEff=EFFECT_MAX;
  }
 else   prgAddSide=0;
}

Fixed version (ground truth):
@Override public void updateEntity(){
  super.updateEntity();
  ++ticksExisted;
  if (worldObj.isRemote)   return;
  int energyReq=ENERGY_MAX - currentEnergy;
  if (currentEnergy < 0)   currentEnergy=0;
  if (currentEnergy < ENERGY_MAX && !(!this.isRSActivated && this.getCurrentBehavior() == EnumBehavior.RECEIVEONLY)) {
    ItemStack sl=slots[2];
    if (sl != null && sl.getItem() == Items.redstone) {
      if (energyReq > 500) {
        this.decrStackSize(2,1);
      }
      currentEnergy+=500;
    }
 else     if (sl != null && sl.getItem() instanceof ISpecialElectricItem) {
      ISpecialElectricItem item=(ISpecialElectricItem)sl.getItem();
      if (item.canProvideEnergy(sl)) {
        int cn=energyReq < 128 ? energyReq : 128;
        cn=item.getManager(sl).discharge(sl,cn,2,false,false);
        currentEnergy+=cn;
      }
    }
  }
  if (this.isUsing) {
    for (    EntityPlayer charger : chargers) {
      currentEnergy-=5;
      this.doHealing(charger);
      if (worldObj.getWorldTime() % 15 == 0) {
        worldObj.playSoundAtEntity(charger,"String_Node_Str",0.3F,1.0F);
      }
      if (currentEnergy <= 0) {
        this.chargers.clear();
        this.isUsing=false;
        worldObj.playSoundAtEntity(charger,"String_Node_Str",0.5F,1.0F);
      }
    }
  }
  if (slots[0] != null && slots[0].getItem() == Items.potionitem) {
    int dmg=slots[0].getItemDamage();
    List<PotionEffect> list=Items.potionitem.getEffects(dmg);
    PotionEffect effect=list.get(0);
    if (mainEff < HEALTH_MAX) {
      if (effect.getPotionID() == Potion.heal.getId()) {
        if (currentEnergy > 5) {
          currentEnergy-=5;
          prgAddMain++;
        }
 else         currentEnergy=0;
        if (prgAddMain >= PROGRESS_TIME) {
          this.setInventorySlotContents(0,null);
          mainEff+=(effect.getAmplifier() == 0 ? 12 : 18);
          prgAddMain=0;
        }
      }
 else       if (effect.getPotionID() == Potion.regeneration.getId()) {
        if (currentEnergy > 5) {
          currentEnergy-=5;
          prgAddMain++;
        }
 else         currentEnergy=0;
        if (prgAddMain >= PROGRESS_TIME) {
          this.setInventorySlotContents(0,null);
          if (dmg == 8193)           mainEff+=36;
 else           if (dmg == 8257)           mainEff+=96;
 else           if (dmg == 8225)           mainEff+=38;
          prgAddMain=0;
        }
      }
 else       prgAddMain=0;
    }
    if (mainEff > TileHealthCharger.HEALTH_MAX)     mainEff=HEALTH_MAX;
  }
 else   prgAddMain=0;
  if (slots[1] != null && slots[1].getItem() == Items.potionitem) {
    int dmg=slots[1].getItemDamage();
    List<PotionEffect> list=Items.potionitem.getEffects(dmg);
    PotionEffect effect=list.get(0);
    if (TileHealthCharger.availableIds.contains(effect.getPotionID()) && sideEff < EFFECT_MAX) {
      if (this.sideEffectId == 0 || effect.getPotionID() == sideEffectId || this.sideEff == 0) {
        this.sideEffectId=effect.getPotionID();
        if (currentEnergy > 5) {
          currentEnergy-=5;
          prgAddSide++;
        }
        if (prgAddSide >= PROGRESS_TIME) {
          this.setInventorySlotContents(1,null);
          sideEff+=effect.getDuration();
          prgAddSide=0;
        }
      }
 else       prgAddSide=0;
    }
    if (sideEff > TileHealthCharger.EFFECT_MAX)     sideEff=EFFECT_MAX;
  }
 else   prgAddSide=0;
}