Does dirty power shorten the life of a laptop battery?

Question

I have a two year old laptop that has spent most of it's life in a third world country where the power is very dirty*. Does the dirty power shorten the life of the battery or will it have no effect?

I'm no battery expert but my gut feeling is that it won't make any difference because the transformer will only give my a specific voltage regardless of the input voltage.

Is this correct or will the transformer be subject to the principal of garbage in, garbage out?

*Dirty as in subject to spikes and/or brownouts in the power supply.

Answer 1

Short answer: no, nothing will happen because of dirty power.

Notebook power supply does not contain just a transformer; it is switched-mode power supply, and that involves much deeper level of conversion, output control and efficiency. For example, typical supply can work both on 220V and 110V networks. Moreover, there is another switch-mode converter inside your notebook which charges the battery, so the power that charges the battery is "double-converted". Basically it means that any spikes were filtered away.