Mal-power protection circuit

I am trying to design a circuit to protect my electric bicycle charger from power supply fluctuations. These are the likely power supply fluctuations that regularly occur here
1. Continuous Low voltage (as low as 80 V) [220 Volt system here]
2. Sudden bursts of Low or 0 Voltages (I don't know how that occurs, but sometimes that occurs)
3. Sudden high Voltage. (Sometimes Ultrahigh due to lightning)
4. Constantly On-Off-On-Off-On-Off Supply for a long time. (I hope you understand what I mean)

So, I would like to protect the charger from virtually every kind of power supply fluctuations.

Currently I have a mind of doing this
1. Use a step-down transformer that converts 200 Volts to 12 Volts and use a zener diode to only turn on a Relay (that supplies power to the charger) when the input voltage is above 200 Volt.
2. Similarly use another zener diode to turn-off the relay when input voltage is above 240 volts.

But I don't currently have ideas whether this can protect sudden changes. I also need to be protected from problem No. 4.
So, any help will be greatly appriciated.

Looks like my question or at least way of asking it was quite incorrect. (No reply for so long). I will try to come up with new way of putting it. If you need any clarification, please proceed!

You would probably be best of using a SMPS based battery charger. The good universal ones have a 100 - 250 VAC input range and will power down if the voltage gets to low.

I have a ready made charger that came with the bicycle and its guaranteed (only 6 months though). Moreover I am not Authorized to use other chargers. Why should I use other chargers? Afterall it has been working fine. Its SMPS, I think. (How do you confirm It?).
The only thing the charger seems to be lacking is I think some protection circuits. (I'm sure of this because, I already damaged two chargers due to this)

What do you think of my initial idea?

Okey, lets go one by one.
First I need to make a circuit that switches on a relay only after 5 minutes of stable supply of the mains (this is to protect problem 4 of OP).
My initial Idea is to use a monostabale 555 circuit. But I am not sure how would I able to trigger and retrigger it when mains supply constantly switching ON and OFF.
So, first lets seek answer for this?